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83 Cards in this Set
- Front
- Back
What is the cell theory |
-The cell is the smallest unit of life - all organisms are made of one or more cells -cells only arise from other cells |
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What does the cells shape reflect? |
Its function |
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This is the |
Nucleus |
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What is the largest organelle |
The nucleus |
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What is the function of the nucleus |
Genetic control center; directs protein synthesis |
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What is the rough ER composed of |
Extensive sheets and covered with ribosomes |
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What is the composition of Smooth ER |
Branching tubules with no ribosomes (smooth surface) |
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What is the function of Rough ER |
Protein synthesis and manufacture of cellular membrane |
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The function of Smooth ER |
Lipid synthesis, detoxification, calcium storage |
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Ribosomes |
Small dark granules free in cytosol or on surfaces of Rough ER |
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What is the function of ribosomes |
Interpret genetic code and synthesize polypeptides |
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Golgi complex |
Several closely spaced parallel cisternae with thick edges |
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what is the function of the golgi complex |
-Packages, modifies and separates proteins for secretion from cell. - modifies carbohydrates on proteins |
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lysosomes |
membranous sacs containg acid hydrolases |
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what is the function of lysosomes |
sites of intracellular digestion |
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peroxisomes |
membranous sacs containing catalase and oxidase enzymes |
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in what organs are peroxisomes abundant in? |
the liver and kidney |
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what are the functions of peroxisomes |
detoxification, most important enzyme catalase breaks down hydrogen peroxide |
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mitochondrion |
Rodlike, double membrane structures; inner membrane folded into projections called cristae |
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what is the function of the mitochondria? |
site of ATP synthesis; powerhouse of the cell |
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what is the function of inclusions |
storage for nutrients, waste and cell products |
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centrioles |
paired cylindrical bodies, each composed of nine triplets of microtubles |
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what are the functions of centrioles |
-organize microtubule work -form the spindle as asters during mitosis - form the bases of flagella and cilia |
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microtubules |
cylindrical structures made of tubulin proteins |
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what is the function of microtubules |
-support the cell and give it shape -involved in intracellular and cellular movement -form axonemes (stalk) of cilia and flagella |
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what is the function of the cell membrane |
barrier, communication, transport, |
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what is the cell membrane composed of |
lipids and proteins |
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the heads of phospholipids are _________ and are attracted to _________ |
polar; water |
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the tails of phospholipids are __________ and avoid ____________ |
nonpolar; water |
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the head of phospholipids lie on both the __________ and _________ surfaces while the tails line up in _____________ |
inner, outer, the center |
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cholesterol has both a |
polar (hydoxyl group) and nonpolar (fused ring system) region |
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what does cholesterol do for the cell membrane |
stiffens it |
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integral proteins have both |
hydrophilic and hydrophobic regions |
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Transport |
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the functions of transport |
hydrolyze ATP as an energy source to actively pump substances across membrane |
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receptors for signal transmission |
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function of receptors |
a membrane protein outside of cell with a specific shape that matches the shape of a chemical messenger |
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enzymatic activity |
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function of the enzymatic activity |
catalyzes sequential steps of metabolic pathway |
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cell-cell recognition |
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function of cell-cell recognition |
glycoproteins serve as identification tags |
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cytoskeleton and extracellular matrix (ECM) |
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functions of ECM |
helps maintain cell shape, cell movement, and fixes location of certain membrane proteins |
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cell-cell joining |
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functions of cell-cell joining |
cell adhesion molecules (CAMs) provide temporary binding sites that guide cell migration |
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what makes peripheral proteins different from integral proteins? |
they are not embedded in lipid bilayer |
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function of peripheral proteins |
-helps support membrane from cytoplasmic side -change shape of cell during cell division and muscle contraction |
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glycocalyx is found |
on the surface of animal cells |
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what is glycocalyx composed of? |
carbohydrate portions created by sugars of glycoproteins and glycolipids |
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function of glycocalyx |
-gives identity of molecules -immune system recognition -cell communication by chemical signals |
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Vesicular Transport |
transport of large particles and uses ATP |
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Exocytosis |
V-transport out of cell |
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endocytosis |
V-transport into cell |
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phagocytosis meaning and function |
cell eating- keeps tissue free of debris and infectious microorganisms |
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steps of phagocytosis |
1) cell engulfs large particle by forming a projecting pseudopod (false foot) 2) gets enclosed with membranous sac called phagosome 3) phagosome combines with lysosome and is ingested |
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pinocytosis meaning and function |
cell drinking- cell "gulps" drops of extracellular fluid containing solutes into tiny vesicles |
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Process of exocytosis |
1) membrane bound vesicle migrates to the plasma membrane 2) v-SNAREs bind with t-SNAREs 3) vesicle and plasma membrane fuse and a pore opens up 4)vesicle contents are released to the cell exterior |
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2nd messenger system |
messenger binds to surface receptor (1) receptor activates G protein that is linked to (2) G protein binds to enzyme, adenylate cyclase which converts ATP ---> cAMP the second messenger (3) cAMP activated a kinase in cytosol (4) kinase activates or inactivates other enzyme triggering physiological changes in cell (5) |
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where us microvilli located |
surface of absorptive cells such as intestinal and kidney tubule cells |
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function of microvilli |
shapes cell and increases plasma membrane surface area |
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what are cilia and flagella made of |
centrioles that form base (basal bodies), 2 microtubules that form axoneme (stalk), and arms are composed of protein |
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function of cilia |
moves mucous and trapped substances across surface |
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flagella |
only found in sperm; provides movement |
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protein synthesis |
involves (a) transcription, synthesis of complementary mRNA and (b) translation "reading" of the mRNA by tRNA and peptide bonding of amino acids into polypeptide |
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what coordinates translation? |
ribosomes |
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microfilaments |
form a net work on cytoplasmic side of plasma membrane called membrane skeleton |
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function of microfilaments |
supports phospholipids and microvilli and provides cell movement |
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function intermediate fibers |
help hold epithelial cells together resist stress on cells line nuclear envelope toughens hair and nails (ex: keratin) |
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funtion of microtubules |
hold organells in place maintians cell shape guides organells and molecules from stialk of cilia and flagella |
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Steps of Cell cycle |
-G1 phase the first gap phase: cell is syntehsizing proteins and growing rapidly centrioles start to replicate to prepare for cell division -S phase synthesis phase: DNA is replicated -G2 phase, second gap phase: enzymes needed for division are syntehsized and moved to proper sites -M phase, miotic phase: prophase, metaphase, anaphase, telophase G0 phase- cells that left cycle |
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during mitosis cells |
divide into 2 daughter cells with indentical copies of DNA |
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funtion of mitosis |
generates new cells for growth and repair |
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steps of mitosis |
1) prophase 2) metaphase 3) anaphase 4) telophase |
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in what phase do centromeres split in 2 |
anaphase |
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cytokinesis is the division of the |
cytoplasm |
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sequence of cytokinesis |
myosin pulls in microfilaments this causes crease aroung the cel equator cell pinches into two interphase has begun |
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creasing around the cell equator is called |
cleavage furrow |
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autolysis |
self digestion of dead or degenrate cells |
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when does autolysis happen |
when lysosomes rupture |
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what can cause a lysosome to rupture |
lack of O2 cell is injured excessive amount of vitamin A |
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apoptosis |
"falling away" or programmed cell death |
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apoptosis occurs |
when body of cells are programmed to have limited life span |
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what is an example of apoptosis? |
menstraul cycle |