Cell Membrane
What is the membrane protein present in eukaryotic cells that allows passive water transport?
Aquaporins
Cells such as bacteria are taken up by other cells such as white blood cells by which mechanism?
a) pinocytosis
b) exocytosis
c) receptor-mediated endocytosis
d) phagocytosis
e) facilitated diffusion
d) phagocytosis
It is the sum of chemical processes that occur in living organisms.
Metabolism
True or False. Oxidation reactions and reduction reactions are coupled and always occur together.
True.
What is the transmembrane protein that produces ATP in chemiosmosis?
ATP synthase
It refers to the proteins embedded in the phospholipid bilayer that span the width of the membrane.
Transmembrane proteins.
The function of the enzyme is dependent on ________.
shape.
Which of the following does not describe the first law of thermodynamics?
a. Energy cannot be created.
b. Energy cannot be destroyed.
c. The energy of the universe is constant.
d. In all spontaneous processes, entropy increases.
d. In all spontaneous processes, entropy increases.
Which stage of cellular respiration requires an investment of ATP?
Glycolysis
What is the only stage of cellular respiration that does not immediately produce ATP?
Pyruvate oxidation
An animal cell is placed in a hypertonic solution. What will happen to the cell?
a. It will swell.
b. It will shrivel.
c. It will remain the same.
d. It will prevent the movement of water molecules.
b. It will shrivel.
Which of the following must be true for diffusion to occur?
a. Molecules must have different sizes
b. Channel proteins must always be available.
c. There must be areas of different concentration.
d. Energy must be available.
c. There must be areas of different concentration.
Which of the following statements is false?
a. Anabolism is an exergonic reaction.
b. Anabolism is the synthesis of new molecules from smaller components.
c. Catabolism is a metabolic pathway which releases energy.
d. Catabolism degrades larger molecules to smaller components.
a. Anabolism is an exergonic reaction.
What is the enzyme that phosphorylates glucose into glucose-6-phosphate?
hexokinase
Cellular respiration can best be described as
a) using energy released from breaking high-energy covalent bonds in organic molecules to force ATP formation from ADP and phosphate.
b) taking electrons from food and giving them to phosphate to make ATP.
c) taking electrons from food and giving them to oxygen to make water, using the energy released to drive ATP formation.
d) converting higher-energy organic molecules to lower-energy organic molecules and using the energy released to drive ATP formation.
c) taking electrons from food and giving them to oxygen to make water, using the energy released to drive ATP formation.
This causes the structural change of the Na+/K+ pump allowing passage of these ions through the membrane.
a. Hydrolysis
b. Dehydration
c. Hydrogenation
d. Phosphorylation
d. Phosphorylation
Enzymes change ________________.
a. The free energy of reactants.
b. ΔG of a reaction
c. The free energy of the products.
d. The amount of energy needed to reach the transition state
d. The amount of energy needed to reach the transition state
Which of the following induces an allosteric change to the enzyme?
a. substrate
b. Competitive inhibitors
c. Noncompetitive inhibitors
d. All of the above.
c. Noncompetitive inhibitors
______ is the driving force for primary active transport. _______ is the driving force for secondary active transport.
a. ATP; ATP
b. ATP; Electrochemical gradient
c. Electrochemical gradient; ATP
d. Electrochemical gradient; Electrochemical gradient
b. ATP; Electrochemical gradient
What is the purpose of fermentation reactions?
a) to regenerate NAD+ so glycolysis can continue
b) to make alcohol or lactic acid that cells can metabolize for energy under anaerobic conditions
c) to make additional ATP when respiration can’t make ATP fast enough
d) to slow down cellular oxygen consumption when oxygen is scarce
e) to make organic molecules that cells can store until oxygen becomes available
a) to regenerate NAD+ so glycolysis can continue
Which best describes a biological membrane?
a)two layers of phospholipids with proteins embedded between the two layers
b) a mixture of covalently linked phospholipids and proteins that determines which solutes can cross the membrane and which cannot
c) two layers of phospholipids with proteins either spanning the layers or on the surface of the layers
d) two layers of phospholipids (with opposite orientations of the phospholipids in each layer) with each layer covered on the outside with proteins
c) two layers of phospholipids with proteins either spanning the layers or on the surface of the layers
Which of the following would NOT make the cell membrane more fluid?
a) Saturated hydrocarbon chains
b) Unsaturated hydrocarbon chains
c) cholesterol
d) Both A and B
a) Saturated hydrocarbon chains
What would happen to cytoplasmic enzyme activity inside a cell with a normal cytoplasmic pH of 7.2 if you injected a chemical that would change the pH to 4.0?
a) Little or no change would occur.
b) Enzymes would probably denature.
c) Enzymatic activity would decline.
d) Enzymes would start to add ATP to all reactions.
e) b and c
e) b and c
If you removed the inner membrane of the mitochondrion, could the cell produce any ATP from glucose?
a) yes, by glycolysis and fermentation
b) yes, by the citric acid cycle
c) yes, using the ATP synthase
d) yes, by electron transport
a) yes, by glycolysis and fermentation
Which of the following is not an immediate net product of the typical mitochondrial electron transport chain?
a) ATP
b) water
c) NAD+
d) FAD
e) a proton electrochemical gradient
a) ATP