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116 Cards in this Set
- Front
- Back
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3 domains in evolutionary order
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bacteria, archaea, eukarya
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pyrococcus furiousus- domain?
optimal growth temp? |
archaea- extreme temp environment
optimal growth at 100 degrees C |
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eukarya consists of what 5 kingdoms?
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animal, plant, algae, fungi, protozoa
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thermophilic archaebacteria are what domain
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bacteria
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bacterial cell length
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1-5 micrometers
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eukaryotic cell length
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10-100 micrometers
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What restricts cell size- 3 factors
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surface area/volume ratio
diffusion of molecules maintenance of local concentration |
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cell tricks- refers to what
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creation of compartments(organelles) to hide increased concentrations
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T/F all organelles have a lipid bilayer
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True, and all organelles are intracellular structures carrying out specific functions
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lipid bilayer enclosing nucleus is connected to the _______
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Endoplasmic reticulum
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production of rRNA occurs where specifically?
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nucleolus!
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gates for proteins and soluble materials to enter/exit the nucleus
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nuclear pores
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mitochondria have ___ (1/2/3?) bilayer membranes
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2
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mitochondrial structure includes 4 parts
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1 outer membrane
2 intermembrane space 3 inner membrane; infoldings = cristae 4 the matrix |
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processes that occur in mitochondria
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krebs cycle, respiration, atp production
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oxygen is used to generate energy in the _______
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mitochondria
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what type of dna do mitochondria have
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ribosomes
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what separates rough from smooth ER?
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ribosomes are only on the rough
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T/F- Ribosomes severed from microsomes make first a smaller, processed protein and later
a longer form with signal sequence intact |
True
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T/F- Ribosomes severed from microsomes make first a longer, processed protein and later
a smaller form with signal sequence intact |
False
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Rough ER synthesizes what?
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proteins- membrane proteins, secreted proteins, and many others
lipids |
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"N-linked" glycosylation refers to what organelle
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Rough ER
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Smooth ER- functions
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lipid synthesis
site of detoxification of chemicals |
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archae cell size
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1-5 micrometers
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Golgi Apparatus- processes what?
synthesizes what? sorts what? |
Golgi Apparatus
processes (glycosylates) proteins synthesized on rough ER synthesizes glycolipids (polysaccharides) sorts proteins to destinations |
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Role of ER and Golgi in protein secretion:
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ER- initial glycosylation of proteins
Golgi- completes glycosylation of proteins |
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lysosomes come from...
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golgi vesicles
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lysosomes perform what function
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breakdown of major macromolecules- carbs, lipids, proteins to their subunits
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How do lysosomes maintain acidity, and what enzymes benefit from this?
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maintain acidity with proton pumps in lysosomal membrane
contain enzymes called acid hydrolases that are active at acidic pH |
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lysosome is the ______ ____ of the cell
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recycle center
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what are the two recycle centers of the cell
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lysosome
proteosome |
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microbodies, also known as _______, degrade _______ and ________ and _________
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aka peroxisomes
degrade fatty acids, unusual compounds and hydrogen peroxide |
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what do microbodies produce, and then degrade (using what enzyme), and why
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hydrogen peroxide
degrade it using enzyme catalase because it is highly toxic to cells |
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functions of peroxisomes (microbodies)(4)
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1. degrade fatty acids
2. degrade unusual compounds 3. detoxify compounds such as methanol, ethanol and formaldehyde 4. produce and degrade hydrogen peroxide |
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what do plant cells have that animal cells dont?
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extra large vacuoles and chloroplasts
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endosymbiont theory... explain
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bacteria was phagocytosed by eukaryote and was digested, and eventually became mitochondria (and cyanobacteria became chloroplasts)
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T/F- the Smooth ER produces proteins
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False
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describe golgi apparatus
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processing station w/ vesicles fusing to and budding off of it
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functions of vacuoles
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Vacuole Functions
1. store nutrients, water, ions, and waste materials 2. in plants specifically- maintain turgor pressure (to keep plant from wilting) |
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chloroplasts are found only in what two categories of organism?
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plants and algae
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photosynthesis also known as
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carbohydrate synthesis
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Chloroplasts...
contain __ and ___ synthesize ___ and ____ T/F is a plastid |
contain DNA and ribosomes
synthesize protein and lipids is one of the plastids, True |
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Chloroplasts have 5 components
list them |
outer membrane
intermembrane space inner membrane stroma thylakoid membranes: grana |
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cytoplasm
what is it what is in it does it have a membrane like other organelles |
cytosol (viscous gel) with organelles
fat droplets glycogen granules free ribosomes the cytoskeleton *no membrane |
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Cytoskeletal composition
(tubules/filaments and diameter) |
microtubules (tubulin)- 20 nm diam
intermediate filaments(various proteins)- 10 nm microfilaments (actin) - 7nm |
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explain structural error of prions
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prions are proteins that are incompletely folded- they aggregate and then cause disease
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functions of membranes- 5
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cell barrier and permeability regulator
transport processes organization and localization of function signal detection and transmission adhesion and cell-cell communication |
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the fact that lipid soluble substances penetrate the membrane better than water soluble substances tells us that...
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lipid is part of the cell membrane
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phospholipids are composed of
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a. fatty acyl chains esterified to positions 1 and 2 of glycerol
b. a phosphate ester and an amino alcohol such as choline, ethanolamine, or serine at the 3 position of glycerol |
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phospholipids are polar, nonpolar, or amphipathic?
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amphipathic is most correct- have charged head group and uncharged nonpolar parts
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self association of phospholipids into bilayer is due to
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hydrophobic interactions
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phospholipids form a _____, rather than a glob like __________s do, becase the polar head group can hydrogen bond with water and thus does not need to avoid water
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bilayer
triacylglycerols form a glob instead |
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function of sterols, and main sterol present in plant and animal membranes (2 different sterols)
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cholesterol main sterol in animal membranes
phytosterol main sterol in plant membranes function to stabilize and strengthen the membranes |
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What did the Langmuir isotherm help us to discover w/ respect to lipid structure?
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1. amphipathic nature of lipids
2. used to determine that the membrane was a bilayer |
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fatty acid tails- # carbons?
avg length in nm? |
12-20 carbons, avg 16-18
length 6-8 nm |
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Whats the difference b/t the inner and outer layers of the lipid bilayer
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outer membrane is enriched with glycolipids
inner membrane PE, PS, PI also differ in level of saturation of fatty acid tails |
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membrane asymmetry...
created during what? by enzymes only on ___ _____ of the membrane enzymes known as _______ |
created during biosynthesis
by modifying enzymes only on one site e.g. glycosylation enzymes known as flippases |
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lipid mobility
slow/fast? types of mvmt? |
move fast- small MW- 800 Da
rotation, lateral, and some flip flop- though rare b/c hydrophobic/hydrophilic mix- requires flippases |
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florescence recovery after bleaching shows what?
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the rate of diffusion of lipids into bleached area
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Tm is what?
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temperature where transition occurs between solid gel-like state and fluid state (like MP)
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3 parameters that affect melting point
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fatty acid length
saturated vs unsaturated sterols |
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differential scanning calorimetry measures what?
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lipid bilayer melting point
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T/F cholesterol H- Bonds with phospholipid head groups?
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False,
hydroxyl hydrogen of cholesterol H-bonds with ester bond of phospholipid fatty acids, not head, and thus perturbs packing of lipids |
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Cholesterol;
-is _____ and thus makes membrane less flexible -has ______ effect on packing tails thus making the membrane more flexible -decreases/increases permeability of membrane |
Cholesterol;
-is more rigid and thus makes membrane more flexible -disrupts the packing tails thus making the membrane more flexible -decreases permeability of membrane |
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cis and trans fatty acids are produced during ___ ________
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partial hydrogenation
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trans-fatty acids raise/lower melting point
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raise
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natural unsaturated fatty acids are almost always cis or trans
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cis
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the ability of an organism to modify its membrane viscosity is known as what?
and how does an organism accomplish this? |
homeoviscous adaptation
occurs by changing carbon chain length, or changing saturation level of fatty acids |
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lipid rafts are also known as...
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microdomains
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microdomains... explain structure
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aka lipid rafts-
cholesterol and lipid (esp. glycosphingolipid) rich structures in the membrane, structure more rigid like an island in the membrane often enriched in signal transduction proteins |
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on a TLC plate, where membrane lipids are placed in a nonpolar solvent, which membrane molecules travel farthest?
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the less polar travel farther
cholesterol travels farthest |
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human erythrocyte protein/lipid ratio
chloroplast thylakoid protein/lipid ratio |
1.14 for erythrocyte
2.33 for thylakoid |
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peripheral proteins are
intrinsic/extrinsic covalent/noncovalent |
extrinsic, noncovalent association with outside of bilayer
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integral proteins are intrinsic/extrinsic
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intrinsic- pass through bilayer
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lipid anchored proteins are
integral/extrinsic |
integral
the lipid part of lipoprotein is anchored in bilayer |
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integral proteins- most common structure is alpha-helical/beta-sheet
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alpha, betas are very rare
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alpha helical transmembrane proteins consist of
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20-30 amino acids and single or multiple helixes
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hydropathy analysis can be used to predict _____
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transmembrane sequences, approx 20 hydrophobic amino acids
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the membrane of erythrocytes is composed of 52%______, 40% ______, and 8% _______ by weight
where are the carbohydrates found? |
the membrane of erythrocytes is composed of 52%_proteins, 40% _lipids, and 8% _carbohydrates
the carbohydrates are found on the lipids and proteins |
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lipid weight _____ Da
protein weight avg ______ Da |
lipid weight 800 Da
protein weight avg 40,000 Da |
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Why is the Beta Barrel membrane protein stable?
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because the beta sheet has H-bonds between its own strands, which wrap into a barrel shape, leaving only hydrophobic sidechains on the outside
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where are beta barrels found?
what organisms |
outer membrane of gram negative bacteria, and some membrane acting toxins
ex. porins |
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why is the alpha helix membrane protein stable?
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satisfies polypeptide backbone H-Bonding, and has hydrophobic sidechains that face outward into lipids
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examples of helix bundle transmembrane proteins?
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HGH receptor, insulin receptor, ATP binding cassette family, MDR proteins, 7TM receptors- G protein linked receptors
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lipid anchored proteins
myristylation and palmytilation refer to proteins anchored where? farnesylation and geranylation? |
lipid anchored proteins
myristylation and palmytilation - anchored at plasma membrane covalent to fatty acids farnesylation and geranylation- in cytosol |
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T/F all membrane proteins can move laterally within the lipid bilayer
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False, only most
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the cell fusion experiment demonstrated what?
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membrane protein mobility
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what are the three components of the cytoskeleton, and explain their structure/names
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microfilaments- actin
microtubules-tubulin intermediate filaments- composed of many types of proteins which are covalently linked to each other |
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asymmetry of membrane proteins-
oligosaccharides of glycoproteins on interior/exterior surface of plasma membrane |
oligosaccharides of glycoproteins are on the exterior surface of the plasma membrane
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How to determine sidedness of membrane proteins...
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use lactoperoxidase- an enzyme that cannot penetrate the plasma membrane
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solutes refers to
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ions and small organic molecules
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what passes through the membrane by simple diffusion?
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gases- O2, CO2, small organic molecules
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facilitated diffusion occurs for passage of what molecules? (3)
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glucose, water, ions
via glucose transporter, aquaporin, and ion channels |
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glucose transport across membrane is simple/facilitated and involves what protein
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facilitated (at least in this case) with GLUT1 protein
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carrier proteins are involved in facilitated/active transport and are also known as __________, and two examples are _ and ___
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facilitated and active
permeases glucose transporter, and anion exchange protein |
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carrier proteins follow linear/michaelis menton kinetics, are specific for metabolite, and can either be uniport or coupled transport
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follow enzyme- michaelis menton kinetics
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porin and aquaporin are types of ____ proteins
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channel
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glucose transporter is a uniport/coupled transport mechanism
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uniport
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anion exchange program is uniport/antiport/symport mechanism?
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antiport
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channel proteins including ion channels, porins and aquaporins are specific/nonspecific for metabolites they let pass through
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specific, except for porins
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porins are ______ proteins found on the outer ________ membrane, in addition to the membranes of _______ and ________ (2 organelles and one domain)
passes metabolites smaller than ______ Daltons |
channel proteins
mitochondrial chloroplasts and bacteria smaller than 5000 daltons |
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functions of active transport (3)
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uptake nutrients, secrete waste, maintain non equilibrium ion concentrations
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T/F uniport symport and antiport can all three be either diffusion(simple or facilitated) or active transport
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True
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P-Type ATPase
P stands for what give example |
phosphorylated intermediate
Na/K ATPase |
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V-Type ATPase
V stands for what, what does it do where found |
vacuole
proton pump in organelles such as vacuoles lysosomes and Golgi complex |
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F-Type ATPase
what does F stand for... whats special about it found in what |
F for flexible- bi-directional can pump protons using ATP or leak protons making ATP
found in bacteria, mitochondria, chloroplasts |
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ABC Type ATPase
whats special about it |
can transport a variety of solutes, not just cations like the other ATPases
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what factors affect rate of diffusion across the bilayer?
which travel fastest |
size, polarity, charge
small, nonpolar, uncharged molecules diffuse the fastest |
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Na/Glucose symporter, glucose transported up/down concentration gradient driven by Na ion (in same/different direction) up/down a Na concentration gradient
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Na/Glucose symporter, glucose transported up concentration gradient driven by Na ion (in same direction) down a Na concentration gradient
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halobacteria use _____ energy to pump protons, instead of ATP
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light
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for what factors are ion channels specific for a certain ion
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size of channel and binding of ion
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what type of active transport involves a phosphorylated intermediate?
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direct active transport by P-type ATPases
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Na/Glucose symporter, glucose transported up/down concentration gradient driven by Na ion (in same/different direction) up/down a Na concentration gradient
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Na/Glucose symporter, glucose transported up concentration gradient driven by Na ion (in same direction) down a Na concentration gradient
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halobacteria use _____ energy to pump protons, instead of ATP
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light
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for what factors are ion channels specific for a certain ion
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size of channel and binding of ion
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what type of active transport involves a phosphorylated intermediate?
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direct active transport by P-type ATPases
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