Navigation » List of Schools » West Los Angeles College » Chemistry » Chem 221 – Biochemistry for Science Majors » Fall 2021 » L14 Membranes
Below are the questions for the exam with the choices of answers:
Question #1
A Carbohydrates
B lipids
C Proteins
D hydrophilic heads
Question #2
A a bilayer made of lipids with polyunsaturated 18 carbon-fatty acids
B a bilayer made of lipids with polyunsaturated 16 carbon-fatty acids
C a bilayer made of lipids with saturated 16 carbon-fatty acids
D a bilayer made of lipids with saturated 18 carbon-fatty acids
E All of the above are equivalent in fluidity.
Question #3
A salt moves into the slug, poisoning it
B salt moves out of the slug, depriving it of essential minerals
C water moves out of the slug, causing dehydration
D water moves into the slug, causing it to swell
Question #4
A Osmosis
B Diffusion
C Semi-permeable
D Concentration gradient
Question #5
A Hypertonic
B Hypotonic
C Homeostasis
D Isotonic
Question #6
A Isotonic
B Diffusion
C Solution
D Osmosis
Question #7
A stay the same size
B swell
C impossible to tell
D shrink
Question #8
A active transport.
B pinocytosis.
C osmotic pressure.
D osmosis.
Question #9
A move across the membrane to the outside of the cell.
B continue to move across the membrane in both directions.
C stop moving across the membrane.
D move across the membrane to the inside of the cell.
Question #10
A Pump
B Facilitated diffusion
C Symport
D Simple diffusion
Question #11
A specific gas transport proteins
B secondary active transport
C passive diffusion through the lipid bilayer
D primary active transport
Question #12
A steroid lipids at certain temperatures
B cholesterol at certain temperatures
C poor alignment of the fatty acids tails
D double bonds between carbon atoms in the fatty acid tails
E all of the above
Question #13
A Small polar molecules can diffuse through a cell membrane along a concentration gradient.
B Small polar molecules require specific transport systems for passage across a membrane.
C Small inorganic ions can diffuse through a cell membrane along a concentration gradient.
D Small polar molecules cannot be transported through a cell membrane against a concentration gradient.
Question #14
A Cell membranes are permeable to most inorganic ions.
B Cell membranes are impermeable to most molecules.
C Cell membranes maintain the shape of cells.
D Cell membranes retain the contents of cells.
Question #15
A Integral membrane proteins have ends rich in hydrophilic amino acids.
B Transmembrane porins have hydrophilic amino acids that point inwards in the beta-barrels.
C Integral membrane proteins have transmembrane domains rich in hydrophobic amino acids.
D Integral membrane proteins are anchored to the lipid bilayer by ionic bonds.
Question #16
A Membrane fluidity is increased when there is a high proportion of saturated fatty acids in the glycerophosphate molecules that make up the bilayer.
B Membrane fluidity is increased when there is a high proportion of trans unsaturated fatty acids in the glycerophosphate molecules that make up the bilayer.
C Membrane fluidity is decreased when there is a high proportion of cis unsaturated fatty acids in the glycerophosphate molecules that make up the bilayer.
D Membrane fluidity is increased when there is a high proportion of cis unsaturated fatty acids in the glycerophosphate molecules that make up the bilayer.
Question #17
A Lateral movement of membrane lipids occurs rapidly within the plane of the bilayer.
B Lateral movement of membrane lipids is catalysed by special proteins.
C The inner and outer halves of the lipid bilayer are identical.
D Transverse movement of membrane lipids within the bilayer is unrestricted.
Question #18
A None of the answers is correct.
B cholesterol
C ATP
D magnesium ions
E proteins
Question #19
A membrane asymmetry
B membrane melting temperatures.
C membrane fluidity
D membrane fluidity and membrane melting temperatures.
E All of the answers are correct.
Question #20
A Active transport
B facilitated diffusion
C Diffusion through a uniport
D Passage through ion channels
Question #21
A lipids that contain sphingosine.
B glycolipids
C free fatty acids.
D unsaturated fatty acids.
Question #22
A positioned on the inside center of the bilayer.
B positioned on the extracellular side of the membrane.
C also covalently attached to membrane proteins
D positioned on the intracellular side of the membrane.
E positioned equally on both sides of the membrane.
Question #23
A a bilayer made of lipids with saturated 16 carbon-fatty acids
B a bilayer made of lipids with polyunsaturated 16 carbon-fatty acids
C a bilayer made of lipids with saturated 18 carbon-fatty acids
D a bilayer made of lipids with polyunsaturated 18 carbon-fatty acids
E All of the above are equivalent in fluidity.
Question #24
A infinite
B varying thickness, depending on structure
C None of the answers is correct.
D two
E one
Question #25
A lipids and proteins
B All of the answers are correct
C None of the answers is correct.
D carbohydrates
Question #26
A lipid-linked proteins
B glycolipids
C cholesterol
D integral membrane proteins in contact with the cytoplasm
Question #27
A translocation
B asymmetric longitudinal flipping
C lateral diffusion
D kinesin-mediated movement
E flip-flopping
Question #28
A asymmetry
B selective permeability
C bilayer
D None of the answers is correct.
E amphipathic nature
Question #29
A Movement of one molecule down its gradient is an entropically driven process
B The transport of a molecule up its gradient is an energy-requiring process.
C Passage through a channel allows polar and charged compounds to avoid the hydrophobic core of the plasma membrane, which would otherwise block their entry into the cell.
D The transport of a molecule up its gradient is an exergonic process
Question #30
A Water
B Carrier proteins
C Concentrated solutes
D Energy
Question #31
A An area of equilibrium to an area of high concentration
B An area of low concentration to an area of high concentration
C An area of high concentration to an area of low concentration
D All of the above
Question #32
A reducer
B diffuser
C oxidizer
D pump
E transporter
Question #33
A facilitated diffusion
B None of the choices are correct
C active transport
D osmosis
E diffusion
Question #34
A In accord with the Second Law of Thermodynamics, molecules spontaneously move from a region of higher concentration to one of lower concentration
B The outside surface of a beta barrel is hydrophylic
C There are electrostatic and hydrogen-bonding attractions between the polar head groups and water molecules.
D An entropy increase powers diffusion across the membrane.
Question #35
A facilitated diffusion
B secondary active transport
C simple diffusion
D primary active transport
E passive transport
Question #36
A driven by ATP
B not specific with respect to the substrate
C endergonic
D driven by a difference of solute concentration
E generally irreversible
Question #37
A shifting from aerobic to anaerobic metabolism.
B putting more unsaturated fatty acids into its membranes.
C synthesizing thicker membranes to insulate the cell.
D putting longer-chain fatty acids into its membranes.
E increasing its metabolic rate to generate more heat.
Question #38
A the binding of water to the fatty acyl side chains.
B a decrease in temperature.
C an increase in fatty acyl chain length.
D an increase in the number of double bonds in fatty acids.
Question #39
A Individual lipid molecules in one face (monolayer) of the bilayer readily diffuse (flip-flop) to the other monolayer.
B The bilayer is stabilized by covalent bonds between neighboring phospholipid molecules.
C The polar head groups face inward toward the inside of the bilayer.
D Polar, but uncharged, compounds readily diffuse across the bilayer.
E Individual lipid molecules are free to diffuse laterally in the surface of the bilayer.
Question #40
A They can be removed from the membrane with high salt or mild denaturing agents.
B The domains that protrude on the cytoplasmic face of the plasma membrane nearly always have covalently attached oligosaccharides.
C They undergo constant rotational motion that moves a given domain from the outer face of a membrane to the inner face and then back to the outer.
D The secondary structure in the transmembrane region consists solely of alpha-helices or beta-sheets.
Question #41
A a solution containing detergent
B hot water
C a buffer
D a solution of high ionic strength
E a chelating agent that removes divalent cations
Question #42
A may have functional units on both sides of the membrane
B are generally noncovalently bound to membrane lipids
C penetrate deeply into the lipid bilayer
D can be released from membranes only by treatment with detergents