BHSC 1200 CYTOLOGY EXAM
QUESTIONS AND VERIFIED ANSWERS
The Cell - ANSWER-the basic structural and functional unit of all organisms
What are the plasma membranes 4 functions? - ANSWER-physical isolation between inside ICF and
outside ECF, regulating exchange with environment, monitoring its environment, structural support
Hydrophilic head - ANSWER-interacts with ICF or ECF, mainly water
Hydrophobic tail - ANSWER-interacts with the other hydrophobic tails in the other phospholipid bilayer
What are the functions of membrane proteins? - ANSWER-transporters, anchors, receptors, enzymes
Transporters - ANSWER-selectively move something across the membrane
Anchors - ANSWER-join neighbouring cells with filaments to provide shape
Receptors - ANSWER-bind a specific ligand to alter a cell's function
Enzymes - ANSWER-catalyze chemical reactions
What types of membrane transport do NOT require ATP(energy)? - ANSWER-passive transport -
facilitated diffusion, osmosis and simple diffusion
Why doesn't passive transport require energy? - ANSWER-because they go from a high to low
concentration gradient (follows the concentration gradient)
What does equilibrium mean with respect to concentration gradients? - ANSWER-There is no net
movement, or the concentration is distributed equally.
What does the substance have to be in order to be considered simple diffusion? - ANSWER-substance
has to be small enough and hydrophobic/neutral, it needs to be able to sneak between phospholipids.
What do you need in order for facilitates diffusion to work, and why? - ANSWER-you need a protein door
for the concentration gradient, because this transports molecules that are too large or too polar
What are the two components to facilitated diffusion? - ANSWER-Carrier proteins and channels
How do carrier proteins work? - ANSWER-molecule binds to carrier proteins, which change shape
allowing the molecule to pass through
How do channels work? - ANSWER-interact like a gate
What is the main difference between protein channels and protein carriers? - ANSWER-channels - helps
ions pass through that are too polar
carriers - help molecules pass through that are too large
Specific Facilitated Diffusion - ANSWER-each channel or carrier transports certain molecules or ions only.
most cases, only one substance. (ie. K+ channels, Na+ channels)
Passive Facilitated Diffusion - ANSWER-direction of net movement is always down the concentration
gradient (high to low).
Saturated Facilitated Diffusion - ANSWER-once all transport proteins are in use, rate of diffusion can not
be increased.
Transport maximum - ANSWER-transport rate when all carriers are occupied
What does the transport maximum graph look like? - ANSWER-initially - high rate of transport
plateau's when it is saturated, can no longer increase the rate of transport
Is the transport maximum graph linear? Why or why not? - ANSWER-No, once the point of TM, it
plateaus because we can not increase the rate of transport due to using up all the transporters.
How does diabetes relate to the transport maximum? - ANSWER-You are given a certain number of
glucose transporters, can not increase the rate of transporters so the excess glucose is exerted through
the kidneys/urine. This is due to improper glucose regulation.
How does the transport maximum relate to protein powder? - ANSWER-There is a suggested serving size
on protein powder because that is what you can absorb due to the amount of transporters you have.
Going above the recommended serving size is not ideal because you will have excess protein.
QUESTIONS AND VERIFIED ANSWERS
The Cell - ANSWER-the basic structural and functional unit of all organisms
What are the plasma membranes 4 functions? - ANSWER-physical isolation between inside ICF and
outside ECF, regulating exchange with environment, monitoring its environment, structural support
Hydrophilic head - ANSWER-interacts with ICF or ECF, mainly water
Hydrophobic tail - ANSWER-interacts with the other hydrophobic tails in the other phospholipid bilayer
What are the functions of membrane proteins? - ANSWER-transporters, anchors, receptors, enzymes
Transporters - ANSWER-selectively move something across the membrane
Anchors - ANSWER-join neighbouring cells with filaments to provide shape
Receptors - ANSWER-bind a specific ligand to alter a cell's function
Enzymes - ANSWER-catalyze chemical reactions
What types of membrane transport do NOT require ATP(energy)? - ANSWER-passive transport -
facilitated diffusion, osmosis and simple diffusion
Why doesn't passive transport require energy? - ANSWER-because they go from a high to low
concentration gradient (follows the concentration gradient)
What does equilibrium mean with respect to concentration gradients? - ANSWER-There is no net
movement, or the concentration is distributed equally.
What does the substance have to be in order to be considered simple diffusion? - ANSWER-substance
has to be small enough and hydrophobic/neutral, it needs to be able to sneak between phospholipids.
What do you need in order for facilitates diffusion to work, and why? - ANSWER-you need a protein door
for the concentration gradient, because this transports molecules that are too large or too polar
What are the two components to facilitated diffusion? - ANSWER-Carrier proteins and channels
How do carrier proteins work? - ANSWER-molecule binds to carrier proteins, which change shape
allowing the molecule to pass through
How do channels work? - ANSWER-interact like a gate
What is the main difference between protein channels and protein carriers? - ANSWER-channels - helps
ions pass through that are too polar
carriers - help molecules pass through that are too large
Specific Facilitated Diffusion - ANSWER-each channel or carrier transports certain molecules or ions only.
most cases, only one substance. (ie. K+ channels, Na+ channels)
Passive Facilitated Diffusion - ANSWER-direction of net movement is always down the concentration
gradient (high to low).
Saturated Facilitated Diffusion - ANSWER-once all transport proteins are in use, rate of diffusion can not
be increased.
Transport maximum - ANSWER-transport rate when all carriers are occupied
What does the transport maximum graph look like? - ANSWER-initially - high rate of transport
plateau's when it is saturated, can no longer increase the rate of transport
Is the transport maximum graph linear? Why or why not? - ANSWER-No, once the point of TM, it
plateaus because we can not increase the rate of transport due to using up all the transporters.
How does diabetes relate to the transport maximum? - ANSWER-You are given a certain number of
glucose transporters, can not increase the rate of transporters so the excess glucose is exerted through
the kidneys/urine. This is due to improper glucose regulation.
How does the transport maximum relate to protein powder? - ANSWER-There is a suggested serving size
on protein powder because that is what you can absorb due to the amount of transporters you have.
Going above the recommended serving size is not ideal because you will have excess protein.
