Question 1

Which bond is responsible for linking amino acids together in the primary structure of a protein, as shown in the first image?

Accepted Answer

Peptide bond

Question 2

Given the structure of an amino acid, which group is always attached to the central (alpha) carbon?

Accepted Answer

A carboxyl group ($$-COOH)$$

Question 3

Which of the following side chains would most likely be found in the interior of a protein, away from water?

Accepted Answer

A side chain containing $$-CH_3$

Question 4

Which process breaks peptide bonds and releases free amino acids?

Accepted Answer

Hydrolysis reaction

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 stabilize the secondary structure of proteins?

Accepted Answer

Hydrogen bonds between backbone atoms

Question 7

Which of the following best describes the tertiary structure of a protein?

Accepted Answer

The overall three-dimensional shape stabilized by side chain interactions

Question 8

What is the role of chaperone proteins in cells?

Accepted Answer

They assist in the proper folding of other proteins

Question 9

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

Accepted Answer

Altered protein folding and possibly loss of function

Question 10

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

Accepted Answer

The energy available to do work in a system

Question 11

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

Accepted Answer

Exergonic; energy is released

Question 12

Refer to the third image. What type of reaction is shown, and what does $$\Delta G \u003e 0$$ mean?

Accepted Answer

Endergonic; energy is required

Question 13

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

Accepted Answer

Breakdown of glucose during cellular respiration

Question 14

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

Accepted Answer

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

Question 15

Where on an enzyme does substrate binding and catalysis occur?

Accepted Answer

Active site

Question 16

Which of the following best describes competitive inhibition?

Accepted Answer

An inhibitor binds to the active site, blocking substrate binding

Question 17

What is the effect of negative feedback inhibition on a metabolic pathway?

Accepted Answer

It stops the pathway when enough product is made

Question 18

What is a likely consequence if an enzyme’s active site is altered by mutation?

Accepted Answer

The enzyme may lose its ability to bind substrate

Question 19

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

Accepted Answer

Cofactors are non-protein molecules that assist enzyme activity

Question 20

Which of the following correctly matches the reaction type with its energy change?

Accepted Answer

Catabolic reactions are usually exergonic

Study Guide: Proteins, Energy, and Enzymes

Study Guide - Practice Questions