Question 1

Which part of the amino acid structure is responsible for the unique chemical properties of each amino acid?

Accepted Answer

The side chain (R group)

Question 2

A side chain containing only carbon and hydrogen atoms is most likely to be:

Accepted Answer

Nonpolar

Question 3

Which of the following best describes a hydrolysis reaction?

Accepted Answer

A reaction that breaks a bond by adding a water molecule

Question 4

In the polypeptide chain shown in the first image, what type of bond links the amino acids together?

Accepted Answer

Peptide bond

Question 5

Which level of protein structure is directly determined by the sequence of amino acids?

Accepted Answer

Primary structure

Question 6

Which of the following interactions does NOT stabilize the tertiary structure of a protein?

Accepted Answer

Peptide bonds

Question 7

What is the main function of chaperone proteins in cells?

Accepted Answer

To assist in the proper folding of other proteins

Question 8

If a mutation changes a single amino acid in the primary structure of a protein, what is the most likely consequence?

Accepted Answer

The protein's shape and function may be altered

Question 9

Which of the following best describes Gibb’s free energy ($$\Delta G$$)?

Accepted Answer

The energy available to do work in a system

Question 10

Refer to the second image. What type of reaction is represented by the graph, and what does $$\Delta G \u003c 0$$ indicate?

Accepted Answer

Exergonic; the reaction releases energy

Question 11

Refer to the third image. What does $$\Delta G \u003e 0$$ indicate about the reaction?

Accepted Answer

The reaction is endergonic and non-spontaneous

Question 12

Which of the following is an example of a catabolic reaction?

Accepted Answer

Breakdown of glucose during cellular respiration

Question 13

How does the presence of an enzyme affect the activation energy and $$\Delta G of a $$reaction?

Accepted Answer

It decreases activation energy but does not change $$\Delta G$$

Question 14

Where on an enzyme does substrate binding and catalysis occur?

Accepted Answer

At the active site

Question 15

Which of the following best describes competitive inhibition?

Accepted Answer

An inhibitor binds to the active site, blocking substrate binding

Question 16

What is the role of negative feedback inhibition in metabolic pathways?

Accepted Answer

It stops the pathway when the end product accumulates

Question 17

A mutation causes an enzyme to lose its specific three-dimensional shape. What is the most likely result?

Accepted Answer

The enzyme will lose its ability to bind substrate

Question 18

Which statement best describes the role of cofactors in enzyme function?

Accepted Answer

Cofactors are non-protein molecules that assist enzyme activity

Question 19

Which of the following correctly pairs the reaction type with its energy profile?

Accepted Answer

Condensation reactions are typically anabolic and may be endergonic

Question 20

A cell lacks a functional enzyme required for a key metabolic pathway. What is the most likely consequence?

Accepted Answer

The pathway will be blocked, and intermediates may accumulate

Study Guide: Proteins, Energy, and Enzymes in Biology

Study Guide - Practice Questions