bio test

This question is based on the reaction A + B + C + D shown in the figure. Which of the following terms best describes the forward reaction in Figure 8.1?

exergonic, delta G < 0

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ______ is to _____

exergonic; endergonic

The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as?

feedback inhibition

Which of the following statements is true about enzyme-catalyzed reactions?

The reaction is faster than the same reaction in the absence of the enzyme.

Which of the following is an example of potential rather than kinetic energy?

a molecule of glucose

Which of the following represents the activation energy required for the enzyme-catalyzed reaction in Figure 8.1?

B

Which of the following represents the activation energy required for a noncatalyzed reaction in Figure 8.1?

C

Which of the following is (are) true for anabolic pathways?

C) They consume energy to build up polymers from monomers.

Which of the following in Figure 8.1 would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

D

Which of the following represents the AG of the reaction in the figure?

D

Which of the following statements regarding enzymes is true?

Enzymes increase the rate of a reaction by lowering the necessary activation energy.

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell?

It may be used to form a phosphorylated intermediate.

Why is ATP an important molecule in metabolism?

It provides energy coupling between exergonic and endergonic reactions.

Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's

activation energy

Which of the following types of reactions would decrease the entropy within a cell?

anabolic reactions

Which of the following represents the activation energy required for the enzyme-catalyzed reaction in Figure 8.1?

b

How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction?

by binding to an allosteric site, thus changing the shape of the active site of the enzyme

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

catabolism

Which temperature and pH profile curves on the graphs were most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid?

curves 1 and 4

which curve(s) on the graphs may resent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher?

curves 3 and 5

Which of the following types of reactions would decrease the entropy within a cell?

dehydration reactions

Whenever energy is transformed, there is always an increase in the

energy of the universe

The active site of an enzyme is the region that?

is involved in the catalytic reaction of the enzyme

Some bacteria are metabolically active in hot springs because

their enzymes have high optimal temperatures.