AP Biology Chapter 8

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

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

Feedback inhibition

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

It is lost to the environment

Why is ATP an important molecule in metabolism?

It provides energy coupling between exergonic and endergonic reactions

Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein?

+ delta H- delta S+ delta G

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a change of G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the change of G for the new reaction?

-20 kcal/mol

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

A food molecule made up of energy-rich macromolecules

Which of the following is considered to be an open system?

An organism

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

As a consequence of growing, organisms can create more disorder in their environment than the decrease in entropy associated with their growth

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

Competitive inhibiton

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

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

Catabolism

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

Change in the folding of enzymes

Which of the following tyes of reactions would decrease theentropy within a cell?

Dehydration reactions

The mathematical expression for the change in free energy is delta G= delta H-T delta S. Which of the following is (are) correct?

Delta G is the change in free energy

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

Endergonic

Which of the following is a statement of the first law of thermodynamics?

Energy cannot be created or destroyed

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

Energy coupling

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

The activation energy barrier for this reaction cannot be surmounted

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 enzyme's active site

For living organisms, which of the following is an important consequence of the first law of thermodynamics?

The organism ultimately must obtain all of the necessary energy for life from its environment

Which of the following statements is (are) TRUE about enzyme-catalyzed reactions?

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

Which of the following is TRUE for all exergonic reactions?

The reaction proceeds with a net release of free energy

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

They consume energy to build up polymers from monomers

An important group of peripheral membrane proteins are enzymes, such as the phospholipases that attack the head groups of phospholipids leading to the degradation of damaged membranes. What properties must these enzymes exhibit?

Water solubility

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

by changing the shape of an enzyme