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