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417 Cards in this Set
- Front
- Back
each amino acid in a polypeptide chain is referred to as a ______
|
residue
|
|
the major component of extracellular matrix
|
proteoglycans
|
|
cytochromes
|
carry out electron transport in the ETC
proteins which require a prostetic heme group to function |
|
conjugated proteins
|
proteins containing nonproteinaceous components
|
|
glycogen
|
storage form of glucose, synthesized by liver. mostly found in muscle and liver cells.
Except for digestive tract and kidney, all cells absorb glucose via facilitated diffusion. |
|
insulin
|
increases the rate of facilitated diffusion for glucose and other monosaccharides.
|
|
in the absence of insulin, only ______ and ______ cells are capable of absorbing sufficient amounts of glucose via the facilitated transport system
|
neural and hepatic
|
|
plants form ______ and ________ from glucose
|
starch and cellulose
|
|
2 forms of starch
|
amylose and amylopectin
|
|
minerals
|
the dissolved inorganic ions inside and outside the cell.
assist in the transport of substances entering and exiting the cell by creating electrochemical gradients across membranes. can give strength to a matrix, such as hydroxyapatite in bone. act as cofactors |
|
cofactors
|
a nonprotein component that assists enzyme or protein function
|
|
coenzymes
|
organic cofactors. often vitamins or vitamin derivatives.
|
|
cosubstrates
|
reversibly bind to a specific enzyme, and transfer some chemical group to another substrate.
Cosubstrate is then reverted to its original form. |
|
what distinguishes cosubstrates from normal substrates?
|
the cosubstrate reverts to its original form.
|
|
an enzyme w/out its cofactor is called _________
|
an apoenzyme
|
|
an enzyme w/ its cofactor is called _________
|
holoenzyme
|
|
the classic indication of a competitive inhibitor
|
overcoming inhibition by increasing substrate concentration
|
|
zymogen / proenzyme
|
an inactive form of enzyme. specific peptide bonds are cleaved to irreversibly activate them.
|
|
positive cooperativity
|
the first substrate changes the shape of the enzyme, allowing other substrates to bind more easily
at low substrate concentrations, small increases in substrate concentration increase enzyme efficiency as well as reaction rate. |
|
lyase / synthase
|
enzyme that catalyzes addition rxns w/out use of energy
|
|
ligase / synthetase
|
enzyme that catalyzes addition rxn, but requires energy from ATP or some other nucleotide
|
|
kinase
|
an enzyme which phosphorylates something
|
|
phosphatase
|
an enzyme which dephosphorylates something
|
|
anabolism
|
molecular synthesis
|
|
catabolism
|
molecular degradation
|
|
substrate level phosphorylation
|
glycolysis and Kreb cycle.
the formation of ATP from ADP using the energy released from the decay of high energy phosphorylated compounds as opposed to using the energy from diffusion. |
|
acetyl CoA
|
produced inside the mitochondrial matrix from pyruvate in a rxn that produced NADH and CO2
a coenzyme which transfers two carbons from pyruvate to the 4-carbon oxaloacetic acid |
|
Each turn of the Kreb cycle produced:
|
1 ATP, 3 NADH, 1 FADH2, 2 CO2
oxaloacetic acid reproduced to start cycle over again |
|
fatty acids and amino acids enter metabolic pathway as:
|
acetyl CoA
|
|
glycerol of triglyerides is converted to _______
|
PGAL
|
|
proton-motive force
|
the proton gradient across the inner membrane of the mitochondria
|
|
oxidative phosphorylation
|
production of ATP through the propulsion of protons across the mitochondrial membrane through ATPase
|
|
products and reactants of cellular respiration
|
glucose + O2 --> CO2 + H2O
|
|
gene
|
a series of DNA nucleotides that codes for the production of a single polypeptide or mRNA, rRNA, or tRNA
|
|
euchromatin
|
regions of eukaryotic DNA that are being actively transcribed by a cell
|
|
heterochromatin
|
tightly packed regions of eukaryotic DNA that are not actively transcribed.
repetitive sequence DNA found here |
|
genome
|
the entire DNA sequence of an organism
|
|
The Central Dogma
|
DNA --> RNA --> protein
|
|
each nucleotide is bound to the next by a __________
|
phosphodiester bond
|
|
the end 3' carbon is attached to _______
|
an -OH (hydroxyl) group
|
|
the end 5' carbon is attached to a __________
|
phosphate group
|
|
replisome
|
a group of proteins that governs DNA replication
|
|
SSB tetramer / helix destabilizer proteins
|
prevent the single strand in the loop from folding back onto itself
|
|
exonuclease
|
one of the subunits in DNA polymerase that proofreeds and removes / repairs nucleotides on the strand
|
|
telomeres
|
repeated nucleotide units on the end of eukaryotic chromosomal DNA that protect the chromosomes from being eroded through repeated rounds of replication
|
|
promoter
|
a sequence of DNA nucleotides that designates a beginning point for transcription
|
|
consensus sequence
|
the most commonly found nucleotide sequence of a promoter recognized by the RNA polymerase of a given species
|
|
variation from the consensus sequence causes...
|
causes RNA polymerase to bond less tightly and less often to a given promoter, which leads to those genes being transcribed less frequently.
|
|
transcription requires a _________, while replication requires a ___________
|
promoter, primer
|
|
template / antisense strand
|
the DNA strand which is transcribed.
|
|
coding / sense strand
|
DNA strand which is not transcribed. protects its partner against degradation
|
|
activators and repressors
|
proteins which regulate gene expression at the level of transcription.
bind to DNA close to the promoter and activate or repress the activity of RNA polymerase |
|
operon
|
the genetic unit usually consisting of the operator, promoter, and genes that contribute to a single prokaryotic mRNA
|
|
activators and repressors are often allosterically regulated by...
|
small molecules such as cAMP
|
|
enhancers
|
regulatory proteins in eukaryotes. function similar to activators and repressors, but act at greater distance from the promoter.
|
|
primary transcript
|
the initial mRNA nucleotide sequence arrived at through transcription
|
|
the primary transcript is processed in 3 ways:
|
1) addition of nucleotides
2) deletion of nucleotides 3) modification of nitrogenous bases |
|
5' cap
|
serves as an attachment site in protein synthesis and as a protection against degradation by exonucleases
|
|
poly A tail
|
the polyadenylated 3' end protecting against degradation by exonucleases
|
|
spliceosome
|
a complex formed from snRNPs associating w/ proteins
recognize nucleotide sequences at the end of introns and excise introns, splicing the exons together |
|
restriction enzymes
|
cut nucleic acid at certain nucleotide sequences along the strand
|
|
palindromic
|
reads the same backwards and forwards.
typically, a restriction site will be palindromic |
|
recombinant DNA
|
artificially recombined DNA
|
|
vector
|
a plasmid or infective virus that is used to place recombinant DNA into a bacterium
|
|
probe
|
the radioactively labeled complementary sequence of the desired DNA fragment
|
|
complementary DNA (cDNA)
|
mRNA is reverse transcribed using reverse transcriptase
adding DNA polymerase to cDNA produces a double strand of the desired DNA fragment w/out introns. |
|
polymerase chain reaction (PCR)
|
1) DNA heated to denature
2) cooled --> primers anneal to complementary ends of DNA 3) polymerase added w/ supply of nucleotides --> new DNA |
|
southern blot
|
identifies fragments of known DNA in a larger population of DNA
|
|
northern blot
|
identifies fragments of known RNA in a larger population of RNA
|
|
restriction fragment length polymorphism (RFLP)
|
identifies individuals (as opposed to genes)
based on premise that DNA of different individuals possesses varying distances btwn restriction sites |
|
degenerative
|
more than one series of three nucleotides may code for any amino acid
|
|
unambiguous
|
any single series of three nucleotides will code for one and only one amino acid
|
|
start codon
|
AUG
acts as a codon for the amino acid methionine. |
|
stop codons
|
UGA, UAA, UAG
U Go Away, U Are Away, U Are Gone |
|
initiation
|
tRNA sequesters the amino acid methionine and settles it at the P site. this is the signal for the large subunit to join and form the initiation complex.
|
|
translocation
|
an elongation step in which the ribosome shifts 3 nucleotides along the mRNA toward the 3' end.
|
|
termination
|
stop / nonsense codon reaches A site. proteins known as release factors bind to the A site allowing a water molecule to add to the end of the polypeptide chain
|
|
Proteins injected into the ER lumen are destined to become __________
|
membrane-bound proteins
|
|
signal peptide
|
a 20 amino acid sequence near the front of the polypeptide that is recognized by a protein-RNA signal-recognition particle
|
|
signal-recognition particle
|
carries the ribosome complex to a receptor protein on the ER. protein grows across the membrane, where it is released into the lumen or remains partially attached to the ER.
|
|
mutagens
|
physical or chemical mutations that increase the frequency of mutation above the frequency of spontaneous mutation.
|
|
point mutation
|
a mutation that changes a single base-pair of nucleotides in a double strand of DNA.
|
|
base-pair substitution mutation
|
one type of point mutation in which one base pair is replaced by another
|
|
transition mutation
|
a base-pair substitution in which A-T is switched for G-C or the opposite
|
|
transversion mutation
|
a base-pair substitution that involves a reversal of the same base pairs.
|
|
missense mutation
|
a base-pair mutation that occurs in the amino acid coding sequence of a gene
|
|
neutral mutation
|
a mutation that causes no change in protein function
|
|
silent mutation
|
a mutation in which the amino acid is not changed
|
|
frameshift mutation
|
results when deletions or insertions occur in multiples other than 3. result in nonfunctional protein.
|
|
nonsense mutation
|
a mutation in which a base-pair substitution or an insertion or deletion creates a stop codon
|
|
duplication
|
occurs when a DNA fragment breaks free of one chromosome and incorporates into a homologous chromosome
|
|
translocation
|
when a segment of DNA from one chromosome is inserted into another chromosome
|
|
inversion
|
the orientation of a section of DNA is reversed on a chromosome
|
|
transposition
|
DNA segments can excise themselves from a chromosome and reinsert themselves at another location
|
|
wild type
|
the original state of the organism
|
|
forward mutation
|
changes the organism even more from its original state
|
|
backward mutation
|
reverts the organism back to its original state
|
|
proto-oncogenes
|
stimulate normal growth in human cells
|
|
oncogenes
|
mutated proto-oncogenes that cause cancer
|
|
carcinogens
|
mutagens that cause cancer
|
|
histones
|
globular proteins around which sections of DNA that are not in use are wrapped
|
|
nucleosome
|
formed from 8 histones wrapped in DNA
|
|
chromatin
|
the entire DNA / protein complex
|
|
heterochromatin
|
condensed chromatin. cannot be transcribed in this form
|
|
euchromatin
|
chromatin that can be uncoiled and transcribed. only coiled during nuclear division
|
|
which 2 cell types remain in G0 permanently?
|
neurons and muscle cells
|
|
the G2 checkpoint checks for ____________
|
mitosis promoting factor (MPF)
|
|
asters
|
part of the spindle apparatus. microtubules radiating from the centrioles
|
|
centromeres
|
a group of proteins located toward the center of the chromosome from which the kinetochore microtubules grow
|
|
kinetochore
|
a structure of protein and DNA located at the centromere of the joined chromatids of each chromosomes
|
|
disjunction
|
the split of sister chromatids during anaphase
|
|
spermatogonium / oogonium
|
diploid. germ cells b/f undergoing meiosis.
|
|
primary spermatocyte / oocyte
|
the germ cell after replication occurs in the S phase of interphase
|
|
secondary spermatocyte / oocyte
|
haploid. germ cells after cytokinesis following telophase I.
|
|
reduction division
|
describes meiosis I
|
|
nondisjunction
|
if during anaphase I or II the centromere of any chromosome does not split.
|
|
capsid
|
protien coat on a virus
|
|
virion
|
a mature virus outside the host cell
|
|
how viruses are different from living organisms
|
1) require host to reproduce
2) do not metabolize organic nutrients (use ATP from host) 3) not separated from external environment by membrane 4) possess either DNA or RNA, but never both 5) can be crystallized w/out losing ability to infect |
|
receptor
|
a site on the host onto which the virus attaches. usually a specific glycoprotein on the host cell membrane.
|
|
bacteriophage
|
a virus that infects bacteria. nucleic acid injected through the tail after viral enzymes have digested a hole in the cell wall.
|
|
lytic infection
|
cell produces new viruses until it bursts
|
|
eclipse period
|
the period from infection to when the first fully formed virion appears
|
|
latent period
|
the period from infection to lysis
|
|
virulent virus
|
a virus following a lytic cycle
|
|
lysogenic infection
|
viral DNA is incorporated into the host genome, or
DNA is reverse transcribed from RNA and then incorperated into host's genome |
|
temperate virus
|
a virus in a lysogenic cycle
|
|
provirus
|
a virus that is dormant / latent. viral DNA is incorporated into host DNA
|
|
prophage
|
a dormant / latent virus whose host cell is a bacterium
|
|
plus-strand RNA
|
proteins can be directly translated from the RNA.
|
|
retroviruses
|
carry reverse transcriptase in order to create DNA from RNA. DNA is then incorperated into the genome of the host cell.
|
|
minus-strand RNA
|
the complement to mRNA. must be transcribed to plus-RNA before being translated
|
|
viroids
|
small rings of naked RNA w/out capsids. only infect plants
|
|
prions
|
naked proteins. capable of reproducing themselves, w/out DNA or RNA
|
|
antibodies
|
bind to a viral protein
|
|
cytotoxic T-cell
|
destroy infected cells
|
|
vaccine
|
an injection of antibodies or an injection of a nonpathogenic virus w/ the same capsid or envelope, that allows the host immune system to create its own antibodies
|
|
archaea
|
have similarities to eukaryotes
unlike bacteria, the cell walls are not made from peptidoglycan |
|
fixing CO2
|
reducing it and using the carbon to create organic molecules through the Calvin cycle
|
|
autotrophs
|
organisms capable of using CO2 as their sole source of carbon
|
|
heterotrophs
|
use preformed, organic molecules as their source of carbon
|
|
phototrophs
|
organisms that use light as their energy source
|
|
chemotrophs
|
organisms that use oxidation of organic or inorganic matter as their energy source
|
|
nitrogen fixation
|
the process by which N2 is converted to ammonia
|
|
nitrification
|
creates nitrates, which are useful to plants, from ammonia
|
|
inclusion bodies
|
granules of organic or inorganic matter that may be visible under a light microscope
|
|
amphipathic
|
having both polar and nonpolar regions.
describes phospholipids, glycolipids, etc. |
|
micelle
|
a spherical structure formed from amphipathic molecules in an aqueous solution.
|
|
liposome
|
a vesicle surrounded and filled by aqueous solution. contains a lipid bilayer.
|
|
integral / intrinsic proteins
|
amphipathic proteins that transverse the membrane from the inside of the cell to the outside
|
|
peripheral / extrinsic proteins
|
situated entirely on the surfaces of the membrane. ionically bonded to integral proteins or the polar group of a lipid
|
|
role of cholesterol in membranes
|
moderates membrane fluidity
|
|
hopanoids
|
reduce fluidity of the membrane in prokaryotes
|
|
Brownian motion
|
random movement of molecules
|
|
chemical concentration gradient
|
a gradual change in concentration of a compound over a distance
|
|
electrical gradient
|
applies to molecules w/ a charge.
points in the direction that a positively charged particle will tend to move. |
|
semipermeable membrane
|
slows, but does not stop, diffusion
|
|
two aspects of a compound that affect its semipermeability:
|
size and polarity
|
|
passive diffusion
|
diffusion in which molecules move through leakage channels across the membrane due to random motion
|
|
transport / carrier proteins
|
proteins embedded in the membrane that are designed to facilitate the diffusion of specific molecules across the membrane
|
|
facilitated diffusion
|
diffusion occurs down electrochemical gradient through carrier proteins
|
|
selectively permeable
|
the ability of a membrane to select btwn molecules of similar size and charge using facilitated diffusion
|
|
active transport
|
movement of a compound against its electrochemical gradient. requires expenditure of energy in the form of ATP.
|
|
peptidoglycan
|
makes up the cell wall
|
|
gram-positive bacteria
|
stain purple b/c they have thick peptidoglycan cell wall that prevents the gram stain from leaking out.
|
|
periplasmic space
|
the space btwn the plasma membrane and the cell wall in gram+
the space btwn the two plasma membranes in gram- |
|
gram-negative bacteria
|
appear pink when stained b/c thin peptidoglycan cell wall allows most of gram stain to be washed off.
have second phospholipid bilayer outside cell wall. it contains lipopolysaccharides which protect from antibodies and antibiotics |
|
fimbriae
|
short tenticles which attach a bacterium to a solid surface
not involved in cell motility |
|
bacterial flagella are composed of _______
|
flagellin
|
|
source of energy for flagellum propulsion
|
energy comes from a proton gradient rather than by ATP
|
|
binary fission
|
bacterial asexual reproduction.
works like DNA replication. |
|
plasmid
|
a small circle of DNA that exists and replicates independently of the bacterial chromosome
|
|
conjugation
|
the transfer of a replicated plasmid through a sex pilus btwn two bacteria
|
|
F plasmid / fertility factor
|
a bacterial DNA sequence that codes for the sex pilus that allows conjugation
|
|
R plasmid
|
donates resistance to certain antibiotics
|
|
transformation
|
the process by which bacteria may incorporate DNA from their external environment into their genome
|
|
transduction
|
capsid of bacteriophage mistakenly encapsulates a DNA fragment of host cell, then injects harmless bacterial DNA fragments into host cell.
|
|
vector
|
the virus that mediates transduction
|
|
endospore
|
allows gram-negative bacteria to lay dormant when there is a lack of nutrients.
must be activated b/f it can germinate and grow. endospore activated by heating. germination triggered by nutrients. |
|
fungi
|
eukaryotic heterotrophs that obtain their food by absorption rather than by injestion.
|
|
saprophytic
|
to live off dead organic matter
|
|
septa
|
fungal cell walls.
perforated to allow for cytoplasmic streaming |
|
septa are made of _________
|
the polysaccharide chitin
|
|
hyphae
|
multiply branched threadlike structures of the fungal growth state
|
|
mycelium
|
a tangled mass of hyphae
|
|
fungal DNA state is mostly:
|
haploid stage predominates, and is the fungal growth state.
|
|
spores
|
haploid structures that give rise to new mycelia.
|
|
yeast
|
single-celled fungi. rarely produce sexually by producing spores.
|
|
budding / sexual fission
|
a small cell pinches off from the single parent cell.
the most common form of asexual reproduction in yeast. |
|
the two mating types of mycelia:
|
+ and -
|
|
when does asexual vs. sexual reproduction occur in fungi?
|
asexual reproduction occurs when conditions are good, sexual reproduction occurs when conditions are tough
|
|
nuclear pores
|
RNA can exit nucleus through nuclear pores, but DNA cannot
|
|
phagocytosis
|
proteins on the particulate matter bind to proteins on the cell --> matter is engulfed
only occurs in a few specialized cells |
|
pinocytosis
|
extracellular fluid is engulfed by invagination of the cell membrane.
performed in most cells, and in a random fashion; nonselective |
|
receptor mediated endocytosis is associated w/ which protein
|
clathrin
|
|
how does phagocytosis differ from receptor-mediated endocytosis
|
the purpose of receptor mediated endocytosis is to absorb the ligands
in phagocytosis, the ligands exist only as signals to initiate phagocytosis of other particles |
|
cisternal space / ER lumen
|
the space inside the ER
|
|
in the Golgi apparatus, proteins are distinguished based upon which 2 things?
|
the signal sequence and carbohydrate chains
|
|
if a protein doesn't have a signal sequence,...
|
they are packaged into secretory vesicles and expelled from the cell
|
|
secretory vesicles
|
protein filled vesicles which expel proteins from the cell through exocytosis
may also contain enzymes, growth factors, or extracellular matrix components act as the vehicle w/ which to supply the cell membrane w/ its integral proteins and lipids, and as a mechanism for membrane expansion |
|
smooth ER
|
produces triglycerides.
cholesterol formation --> steroid production produces phospholipids detoxification of foreign substances |
|
peroxisomes
|
self-replicating (vs. budding off membranes)
detoxification, oxygen concentration regulation, synthesis and breakdown of lipids, metabolism of nitrogenous bases and carbohydrates. |
|
microfilaments
|
squeeze the membrane together in phagocytosis and cytokinesis
|
|
axoneme
|
the major portion of each eukaryotic flagellum and cilium containing microtubules in a 9 + 2 arrangement
|
|
dynein
|
the protein which makes up the cross bridges connecting each of the outer pairs of microtubules to their neighbor.
allows for movement of microtubules --> movement of flagella and cilia |
|
prokaryotic flagella are made from ______
|
a thin strand of a single protein called flagellin
|
|
centrosome
|
the major microtubule-organizing center in animal cells
|
|
centrioles
|
function in the production of flagella and cilia, but are not necessary for microtubule production
|
|
the major component of microfilaments is __________
|
actin
|
|
cytoplasmic streaming
|
responsible for amoeba-like movement. caused by microfilament movement.
|
|
tight junctions
|
act as fluid barrier around cell
|
|
desmosomes
|
join two cells at a single point.
|
|
gap junctions
|
tunnels btwn cells allowing for the exchange of small molecules and ions.
|
|
collagen
|
the structural protein that gives cartilage and bone their tensile strength
|
|
axon hillock
|
generates an action potential in all directions if the electrical stimulus is from the signal received at the dendrites is great enough
|
|
action potential
|
a disturbance in the electric field across the membrane of a neuron
|
|
the resting potential is established by...
|
an equilibrium btwn passive diffusion of ions across the membrane and the Na/K pump
|
|
depolarization
|
voltage gated sodium channels open, allowing Na to flow into the cell, reversing the polarity of the membrane potential so that it is positive inside relative to the outside
|
|
repolarization
|
voltage gated sodium channels close, voltage gated potassium channels open. K+ flows out of the cell making the inside more negative.
|
|
hyperpolarization
|
inside of membrane becomes more negative than the resting potential b/c potassium channels are slow to close.
|
|
electrical synapses
|
composed of gap junctions btwn cells. transmit signal faster than chemical synapses and in both directions.
|
|
chemical synapse
|
unidirectional; slowest step in the transfer of a nervous signal. when action potential reaches synapse, Ca2+ flows into cell, causing neurotransmitters to be released into synaptic cleft
|
|
Brownian motion
|
the random motion of molecules. the means by which neurotransmitters diffuse across the synaptic cleft
|
|
means by which cell prevents overstimulation: (3 things)
|
1) neurotransmitter destroyed by enzyme in matrix of synaptic cleft and its parts recycled by presynaptic cleft
2) neurotransmitter directly absorbed by presynaptic cleft via active transport 3) neurotransmitter may diffuse out of synaptic cleft |
|
second messenger system
|
binding of neurotransmitter to receptor activates another molecule inside the cell to make changes
|
|
myelin
|
electrically insulating sheaths. increases the rate at which an axon can transmit signals.
formed from oligodendrocytes in the CNS formed from Schwann cells in the PNS |
|
sensory neurons are located ______
|
dorsally from the spinal cord
|
|
motor neurons are located __________
|
ventrally
|
|
nerves
|
neuron processes (axons and dendrites) that are bundled together
|
|
somatic nervous system
|
designed primarily to respond to the external environment. contains sensory and motor functions. its motor neurons innervate only skeletal muscle.
voluntary control |
|
autonomic nervous system
|
generally involuntary
|
|
sympathetic
|
"fight or flight" response
part of ANS |
|
parasympathetic
|
"rest and digest" response
part of ANS |
|
the neurotransmitter used by the somatic and parasympathetic nervous systems
|
acetylcholine
|
|
the neurotransmitter used by the sympthetic nervous system
|
epinephrine or norepinephrine
|
|
part of the brain integrating subconscious activities
|
lower brain, consisting of the medulla, hypothalamus, thalamus, and cerebellum
|
|
cerebrum / cerebral cortex
|
the higher brain; stores memories and processes thoughts
|
|
cornea
|
the first place light strikes the eye. most bending of light occurs here.
|
|
when the ciliary muscle contracts...
|
the lens becomes more like a sphere and brings its focal point closer to the lens
|
|
the image on the retina is _______ and ___________
|
real and inverted
|
|
iris
|
the colored portion of the eye which creates the opening called the pupil. controls how much light enters the eye.
|
|
tympanic membrane
|
the eardrum. separates the external auditory canal from the middle ear.
|
|
cochlea
|
detects sound. hair cells and organ or Corti transduce movement into neural signals
|
|
semicircular canals
|
detect orientation and movement of the head
|
|
peptide hormones
|
water soluble, and thus move freely through the blood
have difficulty diffusing through the cell membrane of the effector --> attach to membrane bound receptors instead of diffusing through the membrane |
|
second messenger
|
activates or deactivates enzymes and/or ion channels and creates a cascade of chemical rxns that amplifies the effect of the hormone
|
|
steroid hormones come from...
|
the adrenal cortex, the gonads, or the placenta
|
|
tyrosine hormones
|
the thyroid hormones and the catecholamines
|
|
peptide hormones come from...
|
pituitary, parathyroid, and pancreas
|
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steroid hormones
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require protein transport molecule to dissolve in blood stream
diffuse through cell membrane of effector, combine w/ receptor in cytosol, transported to nucleus where steroid acts on transcription typical effect is to increase # of a certain protein |
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where in cell tyrosine derivative hormones are formed:
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formed by enzymes in the cytosol or on the rough ER
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thyroid hormones
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lipid soluble --> carried through blood by proteins.
bind to receptors in nucleus, increasing transcription of genes |
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hypothalamus
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controls the release of anterior pituitary hormones
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hormones released by the anterior pituitary
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human growth hormone (hGH)
adrenocorticotropin (ACTH) thyroid-stimulating hormone (TSH) follicle-stimulating hormone (FSH) leutinizing hormone (LH) prolactin |
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adrenocorticotropic hormone
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a peptide which stimulates the adrenal cortex to release glucocorticoids via the secondary messenger system using cAMP. Release stimulated by stress.
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glucocorticoids
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stress hormones
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thyroid-stimulating hormone
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stimulates the thyroid to release T3 and T4 via the second messenger system using cAMP.
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prolactin
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promotes milk production of the breasts
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hormones produced by the posterior pituitary
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oxytocin and antidiuretic hormone (ADH)
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oxytocin
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increases uterine contractions during childbirth and causes milk to be ejected from the breasts
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antidiuretic hormone (ADH) / vasopressin
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causes the collecting ducts of the kidneys to become permeable to water, reducing the volume of urine and concentrating the urine.
b/c fluid reabsorbed, increases blood pressure |
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adrenal cortex secretes:
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only steroid hormones; aldosterone and cortisol
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mineral corticoids
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one type of steroid hormone secreted by the adrenal cortex
affect the electrolyte balance in the blood stream think aldosterone |
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glucocorticoids
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one type of steroid hormone secreted by the adrenal cortex
increase blood glucose concentration and effect fat and protein metabolism think cortisol |
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aldosterone
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a mineral corticoid that acts in the distal convoluted tubule and collecting duct to increase Na and Cl adsorption and K and H secretion.
creates net gain of particles in the plasma, which results in an eventual increase in blood pressure. |
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cortisol
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a glucocorticoid that increases blood glucose levels by stimulating the creation of glucose and glycogen in the liver.
degrades fat and proteins. a stress hormone |
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catecholamines
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tyrosine derivatives synthesized in the adrenal medulla.
epinephrine and norepinephrine "fight or flight" stress hormones |
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T3 and T4
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increase the basal metabolic rate (resting metabolic rate)
lipid soluble tyrosine derivatives synthesized in the thyroid |
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calcitonin
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a peptide hormone released by the thyroid gland which decreases blood calcium level by decreasing osteoclast activity.
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endocrine hormones of the pancreas:
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insulin and glucagon
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insulin
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released when blood levels of carbohydrates or proteins are high.
stimulates storage of carbohydrates as glycogen, fat as adipose tissue, and amino acids as proteins increases permeability of cells to glucose and amino acids |
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parathyroid hormone
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increases blood calcium levels by stimulating proliferation of osteoclasts
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epididymus
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where the sperm matures and is stored until ejaculation
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semen is composed of fluid from... (3 things)
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the seminal vesicles, the prostate, and the bulbourethral glands
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all the eggs of the female are arrested as ___________ at birth
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primary oocytes
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zona pellucida
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a viscous substance secreted around the primary oocyte at puberty
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upon stimulation of ________, theca cells secrete ______
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LH, androgen
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androgen is converted to _________ in the presence of ____________
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estradiol (a type of estrogen) in the presence of FSH
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estradiol
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a steroid hormone that prepares the uterine wall for pregnancy
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luteal surge
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just before ovulation, estradiol level rises rapidly, causing an increase in LH secretion. this causes ovulation
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ovulation
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bursting of the follicle
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corpus luteum
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the follicle left behind after ovulation. secretes estradiol and progesterone throughout pregnancy or for 2 wks after ovulation
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corpus albicans
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a degraded corpus luteum that results if the egg is not fertilized
no longer secretes estrogen or progesterone |
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once fertilization occurs, the oocyte...
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goes through the second meiotic division to become an ovum and releases a second polar body
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what stage of development is the egg in when implants in the uterus?
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the blastocyst stage
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human chorionic gonadotropin (HCG)
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a peptide hormone secreted by the egg upon implantation. prevents the degradation of the corpus luteum
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determination
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cells become determined to give rise to a particular tissue early on.
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differentiation
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the specialization that occurs at the end of the development, forming a specialized tissue cell
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induction occurs when...
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one cell type affects the direction of differentiation of another cell type
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mucous cells
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secrete mucus to lubricate the stomach walls so that food can slide along easily and to protect the epithelial lining from the acidic environment of the stomach
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chief cells
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secrete pepsinogen, the zymogen precursor to pepsin
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pariental cells
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secrete HCl
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G cells
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secrete gastrin, a large peptide hormone which is absorbed into the blood and stimulates parietal cells to secrete HCl
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acetylcholine
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increases the secretion of all gastric cell types
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gastrin and histamine
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increase HCl secretion into the stomach
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digestion in the small intestine occurs in the __________
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duodenum
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absorption in the small intestine occurs in the...
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jejunum and ileum
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brush border
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the microvilli that cover the intestinal wall, increasing surface area
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goblet cells
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epithelial cells which secrete mucus to lubricate the intestine and help protect the brush border from mechanical and chemical damage
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the fluid in the duodenum has a pH of _______ due to _______
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6 due to bicarbonate ions secreted from the pancreas
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all enzymes released by the pancreas are _________
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zymogens
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trypsin and chymotrypsin
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degrade proteins into small carbohydrates
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bile
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produced by the liver and stored in the gall bladder
emulsifies fat, increasing the surface area for lipase |
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large intestine
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water and electrolyte absorption
contains symbiotic E coli bacteria which produce vitamins |
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glucose is dragged into the enterocyte by __________
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sodium
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in all cells except _______ and ________, glucose is transported down its concentration gradient via facilitated diffusion
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enterocytes and cells of the renal tubule
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byproduct of gluconeogenesis from proteins
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ammonia, which is converted to urea by the liver and then excreted in the urine by the kidney
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fatty acids combine immediately once they reach the blood w/ _______
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albumin
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VLDLs
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transport triglycerides from the liver to adipose tissue
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intermediate and low-density lipoproteins
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transport cholesterol and phospholipids to somatic cells
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functions of the liver
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blood storage, blood filtration (of bacteria), carbohydrate metabolism, fat metabolism, protein metabolism, detoxification, erythrocyte destruction, vitamin storage
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when the liver mobilizes fat or protein for energy, the blood...
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acidity increases
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function of the kidney
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to excrete waste products, maintain homeostasis of body fluid volume and solute composition, and to help control plasma pH
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urine is created in the kidney and emptied into the ___________
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renal pelvis
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the renal pelvis is emptied by the _________
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ureter
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the first capillary bed of the nephron
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glomerulus
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Bowman's capsule and the glomerulus make up the __________
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renal corpuscle
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fenestrations
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holes in the glomerular epithelium through which hydrostatic pressure forces plasma into Bowman's capsule. screen out blood and large proteins from entering Bowman's capsule.
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proximal tubule
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takes filtrate after Bowman's capsule. where most reabsorption takes place by means of secondary active transport proteins
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antiport
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an integral membrane transport protein that simultaneously transports two different molecules in opposite directions across a membrane
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the net result of the proximal tubule is to...
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reduce the amount of filtrate in the nephron while changing the solute composition w/out changing the osmolarity
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loop of Henle
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dips into the medulla from the proximal tubule. functions to increase the solute concentration, and thus the osmotic pressure, of the medulla.
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permeability of descending loop of Henle
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permeable to water, but not to salts
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permeability of ascending loop of Henle
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impermeable to water, permeable to salts
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distal tubule
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reabsorbs Na+ and Ca2+ while secreting K+, H+, and HCO3-
net effect is to lower filtrate osmolarity |
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aldosterone
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acts on distal tubule cells to increase sodium and potassium membrane transport proteins
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ADH
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increase the permeability of the collecting tubule to water. makes collecting duct permeable to water
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juxtaglomerular apparatus
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monitors filtrate pressure in the distal tubule
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filtration occurs in the _______
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renal corpuscle
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reabsorption and secretion occurs mostly in the ___________
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proximal tubule
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concentrates solute in the medulla
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loop of Henle
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distal tubule enters into the __________
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collecting duct
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concentrates the urine
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collecting duct
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pneumonic for ADH
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Always Digging Holes (in the collecting duct)
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renin
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secreted in the juxtaglomerular apparatus. stimulates the adrenal cortex to secrete aldosterone.
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systole
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occurs when the ventricles contract
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diastole
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occurs during relaxation of the entire heart and then contraction of the atria
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vagus nerve
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innervates the SA node, slowing the contractions of the heart
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which part of the cardiovascular system is wrapped in smooth muscle
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arteries and arterioles
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diaphragm
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skeletal muscle. innervated by phrenic nerve. creates negative gauge pressure in the thoracic cavity when contracted.
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epiglottis
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prevents food from entering the trachea during swallowing
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the oxygen dissociation curve is shifted to the right by... (3 things)
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an increase in carbon dioxide pressure, hydrogen ion concentration, or temperature
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a shift of the oxygen dissociation curve to the right indicates...
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a lowering of hemoglobin's affinity for oxygen
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most carbon dioxide is carried through the blood in what form?
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as a bicarbonate ion
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the bicarbonate ion formation is governed by the enzyme ________
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carbonic anhydrase
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when bicarbonate moves into the erythrocyte, __________ moves out
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Cl-
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fluid is propelled through the valves in 2 ways:
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smooth muscle contracts, and skeletal muscle squeezes during movement
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albumin
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transports fatty acids and steroids, acts to regulate osmotic pressure of blood.
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the majority of leukocytes are _________
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neutrophils
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T helper cells
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assist in activating B-lymphocytes as well as killer and suppressor T cells.
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the lumen of the sarcoplasmic reticulum is filled w/:
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Ca2+
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the myosin head is released from the active site when...
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ATP attaches to the myosin head
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the force of a contracting muscle depends upon... (2 things)
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the number and size of the active motor units, and the frequency of action potentials
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myoglobin
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an oxygen storing protein similar to hemoglobin, but having only one protein subunit.
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slow-twitch muscle fibers
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red from large amounts of myoglobin. contain large amounts of mitochondria.
split ATP at a slow rate --> slow to fatigue, but also have a slow contraction velocity postural muscles |
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fast-twitch A muscle fibers
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split ATP at a fast rate --> contract rapidly.
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fast-twitch B muscle fibers
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low myoglobin content, contract rapidly, contain large amounts of glycogen
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"growth" of new muscle
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does NOT undergo mitosis
when exposed to forceful, repetitive contractions, diameter of muscle fibers increases, number of sarcomeres and mitochondria increases, sarcomeres lengthen. |
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skeletal muscle
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multinucleated. under voluntary control. striated.
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cardiac muscle
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striated. involuntary. mononucleated. separated by intercalated disks containing gap junctions. mitochondria larger and more numerous than in skeletal muscle.
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action potential plateau
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the action potential of cardiac muscle exhibits a plateau after depolarization. the plateau is created by slow voltage-gated calcium channels which allow calcium to enter and hold the inside of the membrane at a positive potential difference.
plateau lengthens the time of contraction. |
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smooth muscle
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involuntary, innervated by autonomic nervous system. mononucleated.
contain intermediate filaments attached to dense bodies spread throughout the cell. contraction of actin and myosin causes intermediate filaments to pull the dense bodies together. |
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spongy bone
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contains red bone marrow.
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compact bone
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hold yellow bone marrow.
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Haversian canals
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tunnels burrowed by osteoclasts in compact bone
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lamellae
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concentric rings formed by osteoblasts
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canaliculi
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canals through which osteocytes trapped btwn the lamellae exchange nutrients
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Volkmann's canals
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crossing canals which connect Haversian canals
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Haversian canals contain...
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blood and lymph vessels
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osteon / Haversian system
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the entire system of lamellae and Haversian canal
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most calcium in the blood is...
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not in the form of free calcium ions, but is bound mainly by proteins, and to a lesser extent, by phosphates and other anions.
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hydroxyapatite
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stores most of the body's Ca2+. give bone strength.
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collagen
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give bone strength
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cartilage
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flexible, resistant connective tissue. primarily composed of collagen. contains no blood vessels or nerves except in its outside membrane.
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epidermis
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avascular (no blood vessels).
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dermis
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embedded by blood vessels, nerves, glands, and hair follicles. Collagen and elastic fibers provide skin w/ strength, extensibility, and elasticity.
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mendelian ratio
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3:1 ratio dominant to recessive
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phenotype
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the expression of a trait
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genotype
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an individual's genetic makeup
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locus
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the position on respective chromosomes
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law of segregation
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alleles segregate independently of each other when forming gametes. any gamete is equally likely to possess any allele.
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inbreeding
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mating relatives. does not change the frequency of alleles, but does increase the number of homozygous individuals w/in a population
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outbreeding
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mating of nonrelatives which produces hybrids or heterozygotes
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law of independent assortment
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genes located on different chromosomes assort independently of each other
in other words, genes that code for different traits, when located on different chromosomes, do not affect each other during gamete formation |
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karyotype
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a map of the chromosomes
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Barr body
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the inactive X chromosome in an inactive somatic cell
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gene pool
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the total of all alleles in a population
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evolution
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a change in the gene pool
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order of taxonomical classification
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kingdom, phylum, class, order, family, genus, species
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plants and fungi use _______ instead of _________
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divisions instead of phyla
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the subphylum vertebrata is in the phylum _________
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chordata
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three domains
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bacteria, archaea, and eukarya
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species
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all organisms that can reproduce fertile offspring w/ each other
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niche
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the way in which a species exploits its environment
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fitness
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the organism which can best survive to reproduce fertile offspring.
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r-selection
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involves producing large numbers of offspring that mature rapidly w/ little or no prenatal care.
high brood mortality rate. population growth curves are exponential. found in unpredictable, rapidly changing environments. |
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K-selection
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small brood size w/ slow maturing offspring and strong parental care.
sigmoidal growth curve which levels off at the carrying capacity. |
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speciation
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the process by which new species are formed.
begins when gene flow ceases btwn two sections of a population. factors include geographic, seasonal, and behavioral isolation. |
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adaptive radiation
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occurs when several separate species arise from a single ancestral species.
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evolutionary bottleneck
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occurs when a species faces a crisis so severe as to cause a shift in the allelic frequencies of the survivors of the crisis.
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divergent evolution
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when species evolving from the same group maintain a similar structure from the common ancestor
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convergent evolution
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when species independently evolve similar structures
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polymorphism
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the occurrence of distinct forms of a phenotype (height, flower color, etc)
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symbiosis
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a relationship btwn two species
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mutualism
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a relationship that is beneficial for both species
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commensalism
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beneficial for one species and does not affect the other
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when a population is in Hardy-Weinberg equilibrium...
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there is no change in the gene pool
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requirements of a Hardy-Weinberg equilibrium: (5 things)
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1. large population
2. mutational equilibrium 3. immigration or emigration must not change gene pool 4. random mating 5. no selection of the fittest |
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genetic drift
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in small populations, random events cause the death of all members having a certain allele
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Urey-Miller experiment
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one of the early experiments attempting to recreate the atmosphere of early earth
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coacervates
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lipid or protein bilayer bubbles. the first cells are thought to have evolved from them. spontaneously form and grow from fat molecules suspended in water.
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the earliest organisms
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existed 3.6 billion years ago. probably heterotrophs subsisting on preformed organic compounds.
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filled the atmosphere w/ oxygen
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photosynthetic bacteria evolved 2.3 billion years ago
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deuterostomes
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organisms whose anus develops from or near the blastopore
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coelom
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a body cavity w/in mesodermal tissue
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chordata
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possess a notocord, pharyngeal slits, a dorsal hollow nerve cord, and a tail
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vertebrae
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a subphylum of chordata that has the notochord replaced by a segmented cartilage or bone structure. have a distinct brain enclosed in a skull.
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