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Biology 1201 Exam 2 Questions with Answers –
Membranes, Diffusion, Enzymes, Thermodynamics
This file compiles exam 2 questions and verified answers for Biology 1201. It covers
membrane structure, diffusion, osmosis, enzyme function, metabolic pathways, and basic
thermodynamics. The material is detailed and structured to ensure strong preparation for
second-exam topics.
Why are membranes called phospholipid bilayers? - answer✔✔phospholipids have
hydrophilic head and hydrophobic tail, hydrophobic face inside of cell making 2 layers
what is meant by fluid mosaic? - answer✔✔Mosaic of proteins drifting laterally in
fluid bilayer of phospholipids how are membranes adjusted for different
temperatures? - answer✔✔membrane fluidity adjusted by changing the ratio of
unsaturated to saturated fatty acids how do the relative amounts of saturated and
unsaturated fats change? - answer✔✔if you are in a cold environment you want
more saturated fats for your membranes to be fluid; warm environment you want more
saturated fats to make your membranes more solid what is meant by membrane
fluidity? - answer✔✔not too solid, not too fluid why is fluidity an important
property? - answer✔✔preserves membrane function Henrique and Hanson
performed experiments with pigs and examined the effects on the relative amounts of
saturated and unsaturated fats. What did they find? - answer✔✔found that
membrane fluidity can acclimate to temperature; pigs raised wearing underwear in a
, - 2 -:
hot room had subcutaneous fats with higher melting point what types of molecules can
move easily across the membrane? - answer✔✔small nonpolar molecules, gases,
steroid hormones, and water what is simple diffusion? - answer✔✔down the
concentration gradient; does not require supplied energy; does not use a carrier
molecule what is facilitated diffusion? - answer✔✔down the concentration gradient;
employs carrier molecule; does not require supplied energy what is active transport? -
answer✔✔work must me done; must use supplied energy; employs carrier molecule
for which transport processes are carrier molecules involved? - answer✔✔facilitated
diffusion and active transport which transport processes require the input of additional
energy? - answer✔✔active transport what is a semi-permeable barrier? -
answer✔✔only some types of molecules pass through when equilibrium is reached in
diffusion: does movement of molecules stop? - answer✔✔no when equilibrium is
reached in diffusion: does the net movement of molecules stop? - answer✔✔yes
what is meant by hypertonic? - answer✔✔lower water potential; more solutes
dissolved; tend to gain water via osmosis what is meant by hypertonic? -
answer✔✔higher water potential; fewer solutes dissolved; will tend to lose water
via osmosis isotonic - answer✔✔equivalent water potential; equal number of
solutes; no note movement of water in which direction does water flow? -
answer✔✔osmosis and the direction of net water movement what are aquaporins? -
answer✔✔channel proteins which facilitate water diffusion through the membrane
marine bony fish are...? - answer✔✔hypotonic to seawater how do enzymes work? -
Biology 1201 Exam 2 Questions with Answers –
Membranes, Diffusion, Enzymes, Thermodynamics
This file compiles exam 2 questions and verified answers for Biology 1201. It covers
membrane structure, diffusion, osmosis, enzyme function, metabolic pathways, and basic
thermodynamics. The material is detailed and structured to ensure strong preparation for
second-exam topics.
Why are membranes called phospholipid bilayers? - answer✔✔phospholipids have
hydrophilic head and hydrophobic tail, hydrophobic face inside of cell making 2 layers
what is meant by fluid mosaic? - answer✔✔Mosaic of proteins drifting laterally in
fluid bilayer of phospholipids how are membranes adjusted for different
temperatures? - answer✔✔membrane fluidity adjusted by changing the ratio of
unsaturated to saturated fatty acids how do the relative amounts of saturated and
unsaturated fats change? - answer✔✔if you are in a cold environment you want
more saturated fats for your membranes to be fluid; warm environment you want more
saturated fats to make your membranes more solid what is meant by membrane
fluidity? - answer✔✔not too solid, not too fluid why is fluidity an important
property? - answer✔✔preserves membrane function Henrique and Hanson
performed experiments with pigs and examined the effects on the relative amounts of
saturated and unsaturated fats. What did they find? - answer✔✔found that
membrane fluidity can acclimate to temperature; pigs raised wearing underwear in a
, - 2 -:
hot room had subcutaneous fats with higher melting point what types of molecules can
move easily across the membrane? - answer✔✔small nonpolar molecules, gases,
steroid hormones, and water what is simple diffusion? - answer✔✔down the
concentration gradient; does not require supplied energy; does not use a carrier
molecule what is facilitated diffusion? - answer✔✔down the concentration gradient;
employs carrier molecule; does not require supplied energy what is active transport? -
answer✔✔work must me done; must use supplied energy; employs carrier molecule
for which transport processes are carrier molecules involved? - answer✔✔facilitated
diffusion and active transport which transport processes require the input of additional
energy? - answer✔✔active transport what is a semi-permeable barrier? -
answer✔✔only some types of molecules pass through when equilibrium is reached in
diffusion: does movement of molecules stop? - answer✔✔no when equilibrium is
reached in diffusion: does the net movement of molecules stop? - answer✔✔yes
what is meant by hypertonic? - answer✔✔lower water potential; more solutes
dissolved; tend to gain water via osmosis what is meant by hypertonic? -
answer✔✔higher water potential; fewer solutes dissolved; will tend to lose water
via osmosis isotonic - answer✔✔equivalent water potential; equal number of
solutes; no note movement of water in which direction does water flow? -
answer✔✔osmosis and the direction of net water movement what are aquaporins? -
answer✔✔channel proteins which facilitate water diffusion through the membrane
marine bony fish are...? - answer✔✔hypotonic to seawater how do enzymes work? -
