BIOEB101 Test 2 (Metabolism, respiration and photosynthesis q's)

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? A) catabolism (catabolic pathways) B) metabolism C) anabolism (anabolic pathways) D) dehydration

A) catabolism (catabolic pathways)

During a laboratory experiment, you discover that an enzyme-catalysed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction? A) -40 kcal/mol B) -20 kcal/mol C) 0 kcal/mol D) +20 kcal/mol

B) -20 kcal/mol

Why is ATP an important molecule in metabolism? A) Its hydrolysis provides an input of free energy for exergonic reactions. B) It provides energy coupling between exergonic and endergonic reactions. C) Its terminal phosphate group contains a strong covalent bond that, when hydrolysed, releases free energy. D) Its terminal phosphate bond has higher energy than the other two phosphate bonds.

B) It provides energy coupling between exergonic and endergonic reactions.

Which of the following is true when comparing an uncatalysed reaction tterm-8o the same reaction with a catalyst? A) The catalysed reaction will be slower. B) The catalysed reaction will have the same ∆G. C) The catalysed reaction will have higher activation energy. D) The catalysed reaction will consume all of the catalyst.

B) The catalysed reaction will have the same ∆G.

Which of the following is true for all exergonic reactions? A) The products have more total energy than the reactants. B) The reaction proceeds with a net release of free energy. C) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. D) A net input of energy from the surroundings is required for the reactions to proceed.

B) The reaction proceeds with a net release of free energy.

The lock-and-key analogy for enzymes applies to the specificity of enzymes ________. A) as they form their tertiary and quaternary structure B) binding to their substrate C) interacting with water D) interacting with ions

B) binding to their substrate

Anabolic pathways ________. A) are usually highly spontaneous chemical reactions B) consume energy to build up polymers from monomers C) release energy as they degrade polymers to monomers D) consume energy to decrease the entropy of the organism and its environment

B) consume energy to build up polymers from monomers

Catabolic pathways ________. A) combine molecules into more energy-rich molecules B) supply energy, primarily in the form of ATP, for the cell's work C) are endergonic D) are spontaneous and do not need enzyme catalysis

B) supply energy, primarily in the form of ATP, for the cell's work

Which of the following is true of enzymes? A) Enzyme function is increased if the 3- D structure or conformation of an enzyme is altered. B) Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. C) Enzymes increase the rate of chemical reaction by lowering activation energy barriers. D) Enzymes increase the rate of chemical reaction by providing activation energy to the substrate.

C) Enzymes increase the rate of chemical reaction by lowering activation energy barriers.

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell? A) It is secreted as waste. B) It is used only to regenerate more ATP. C) It may be used to form a phosphorylated intermediate. D) It enters the nucleus and affects gene expression.

C) It may be used to form a phosphorylated intermediate.

Which of the following is true of metabolism in its entirety in all organisms? A) Metabolism depends on a constant supply of energy from food. B) Metabolism uses all of an organism's resources. C) Metabolism consists of all the energy transformation reactions in an organism. D) Metabolism manages the increase of entropy in an organism.

C) Metabolism consists of all the energy transformation reactions in an organism.

You have discovered an enzyme that can catalyse two different chemical reactions. Which of the following is most likely to be correct? A) The enzyme contains α-helices and β-pleated sheets. B) The enzyme is subject to competitive inhibition and allosteric regulation. C) Two types of allosteric regulation occur: The binding of one molecule activates the enzyme, while the binding of a different molecule inhibits it. D) Either the enzyme has two distinct active sites or the reactants involved in the two reactions are very similar in size and shape.

D) Either the enzyme has two distinct active sites or the reactants involved in the two reactions are very similar in size and shape.

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? A) It is used to power yet more cellular work. B) It is used to store energy as more ATP. C) It is used to generate ADP from nucleotide precursors. D) It is lost to the environment.

D) It is lost to the environment.