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35 Cards in this Set
- Front
- Back
What are the functions of the plasma membrane?
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1) physical isolation
2) Regulates exchange with environment 3) Monitors the environment 4) Structural Support |
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List the membranous organelles
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> endoplasmic reticulum
> golgi apparatus > lysosomes > peroxisomes > mitochondria |
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List the non-membranous organelles
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> cytoskeleton
> microvilli > centrioles > cilia > ribosomes > proteasomes |
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What are microvilli? What is their function?
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microvilli are membrane extensions containing microfilaments
They increase the surface area to facilitate absorption of extracellular materials. |
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What are Cilia? What is their function?
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Cilia are long extensions containing microtubule doublets
They move material over the cell surface. |
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What are proteasomes? What is their function?
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Proteasomes are hollow cylinders of proteolytic enzymes with regulatory proteins at their ends
They breakdown and recycle damaged or abnormal intracellular proteins |
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What are ribisomes? What is their function?
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Ribosomes are composed of RNA and proteins. They are found both on the surface of the ER and free in the cytoplasm
They synthesize proteins |
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What are Centrosomes and Centrioles? What is their function?
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A centrosome is composed of two centrioles. Both centrioles are composed of microtubules.
The centrosome is essential for movement of chromosomes during cell division and organization of microtubules in the cytoskeleton. |
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What is the golgi apparatus? What are its functions?
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The golgi apparatus is a stack of flattened membranes containing chambers
It stores, alters, and packages secretory products and lysosomal enzymes |
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What are mitochondria? What do they do?
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mitochondria have a double membrane with the inner membrane folds enclosing important metabolic enzymes
Mitochondria produce 95% of the ATP required by the cell |
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What is the endoplasmic reticulum? What does it do?
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The endoplasmic reticulum is a network of membranous channels extending throughout the cytoplasm
It synthesizes secretory products, and participates in intracellular storage and transport |
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What are peroxisomes, what is their function?
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Peroxisomes are vesicles containing degradative enzymes
They catabolize fats and other organic compounds, and neutralize toxic compounds generated in the process |
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What are lysosomes? What do they do?
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Lysosomes are vesicles containing digestive enzymes
They remove damaged organelles or pathogens within the cell |
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What are the functions of the nucleus?
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The nucleus controls the metabolism, stores and processes genetic information, and controls protein synthesis.
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What weight % of the cell membrane do lipids make up?
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42%
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What weight % of the cell membrane do proteins make up?
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55%
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What is a glycocalyx coating?
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The coating on cells formed by the membrane carbohydrates that lubricate, anchor, act as receptors, and act as identifiers for the immune system.
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List the different types of Membrane proteins
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> Anchoring proteins
> recognition proteins > enzymes > receptor proteins > Carrier Proteins > channels |
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What are the functions of the glycocalyx?
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1) lubricate and protect
2) Anchoring and locamotion 3) specificity in binding (receptors) 4) Recognition (immune response) |
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What are the parameters affecting the permeability of molecules across the cell membrane?
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> size
> electrical charge > molecular shape > Lipid/water solubility |
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List the general types of transport through a plasma membrane.
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> Diffusion
> Carrier-mediated transport > Vesicular transport |
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What are the factors influencing diffusion?
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> Distance the particle has to move
> Molecule size (smaller is faster) > Temperature > concentration gradient > electrical forces |
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What types of molecules can be transported through simple diffusion?
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> lipid soluble compounds
- alcohols - fatty acids - steroids > dissolved gasses |
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What types of molecules can be transported through channel mediated diffusion?
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> small, water soluble compounds and ions
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What is Osmolarity?
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Osmolarity is a measure of solute concentration
(number of moles of osmoles (osm) per liter -measures moles of solute particles rather than moles of solute - 1 mole of NaCl = 2 Osmoles of solute because of dissociation |
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What is Tonicity?
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Tonicity describes the osmotic effect of solution on a cell
i.e. shrinks, swells, stays the same. |
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What does it mean if a solution is isotonic?
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It means that there would be no osmotic flow into or out of a cell if it was placed in the solution.
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What is a hypotonic solution?
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A solution that will cause a cell to swell
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What is a hypertonic solution?
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A solution that will cause a cell to shrink
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What is it called when a red blood cell (erythrocyte) shrinks because of osmosis?
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crenation
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What does it mean if a carrier mediated transport is a cotransport or symport?
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It means that it moves two substances in the same direction?
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What does it mean if a carrier mediated transport is a countertransport or antiport?
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It means it moves one substance in and moves the other out.
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What are the three classes of carrier proteins? Their meaning?
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> Uniport - transports a single molecules
> Symport - two dissimilar solutes are obligatorily transported together in the same direction. > Antiport - two dissimilar solutes are obligatorily transported at the same time but in opposite directions. |
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What are the different "types" of transport. Not the types of proteins.
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> Facilitated diffusion (passive)
- requires no additional energy > Primary Active Transport - molecules move against concentration gradient - requires energy such as ATP > Secondary Active Transport - transport mechanism does not directly require energy - transport is driven by the concentration gradient of another solute |
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What are the two types of vesicular transport
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> Endocytosis - the cell takes in macromolecules by forming new vesicles from the plasma membrane
> Exocytosis - transport vesicles migrate to plasma membrane, fuse with it and release their contents |