Metabolism test

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

Catabolism

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

They consume energy to build up polymers from monomers.

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

Dehydration Reactions

Which of the following is considered an open system?

an organism

Which of the following is true for all exergonic reactions?

The reaction proceeds with a net release of free energy.

A chemical reaction that has a positive △G is correctly described as

endergonic

Why is ATP an important molecule in metabolism?

It provides energy coupling between exergonic and endergonic reactions.

What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways?

energy coupling

Which of the following statements is true concerning catabolic pathways?

They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

It is lost to the environment.

How can one increase the rate of a chemical reaction?

Add a catalyst.

Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in

breaking the bond between glucose and fructose and forming new bonds from the atoms of water.

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

activation energy.

which of the following statements regarding enzymes is true?

Enzymes increase the rate of a reaction.

The active site of an enzyme is the region that

is involved in the catalytic reaction of the enzyme.

According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?

The binding of the substrate changes the shape of the enzymeʹs active site

Which curve represents the behavior of an enzyme taken from a bacterium that lives in hot springs at temperatures of 70°C or higher?

curve 3

Which curve was most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid?

curve 4

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

competitive inhibition

Which of the following is true of enzymes?

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

Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)

cofactor necessary for enzyme activity.

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid.

Succinate is the substrate, and fumarate is the product.

Which of the following terms best describes the reaction?

exergonic

Which of the following represents the △G of the reaction

D

Which of the following bests describes the reaction?

negative △G, spontaneous

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

B

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

c

Which best describes the reaction?

The amount of free energy released as a result of the catalyzed reaction is indicated by ʺd.ʺ

When you have a severe fever, what may be a grave consequence if this is not controlled?

change in the folding of enzymes

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

by changing the shape of a reactant

A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme.

what is substance X?

a substrate

Substance A functions as

an allosteric inhibitor.

The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as

feedback inhibition.

Which of the following statements describes enzyme cooperativity?

A substrate molecule bound to an active site affects the active site of several subunits.

Which of the following is an example of cooperativity?

a molecule binding at one unit of a tetramer allowing faster binding at each of the other three

Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity?

compartmentalization of enzymes into defined organelles

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

exergonic; endergonic

Some bacteria are metabolically active in hot springs because

their enzymes have high optimal temperatures.

If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur?

Nothing; the reaction would stay at equilibrium.

Which reaction would prevail if both Q and S were present in the cell in high concentrations?

L → N

the observed cooperactivity of oxygn binding to hemoglobin can be explained…

allosteric

an unkown molecule….

noncompetitive inhibition

A student is conducting an experiement….

a competitive inhibitor

the optimal conditions for human blood…

increase enzyme concentration

vitamins are essential to the survival of organisms because vitamins usually …

coenzymes