Question 1

Which of the following best describes the process by which amino acids are joined together to form a protein?

Accepted Answer

Amino acids are joined by dehydration synthesis reactions, which remove water to form peptide bonds.

Question 2

Which functional groups are present in every amino acid?

Accepted Answer

A carboxylic acid group, an amine group, and a unique R group

Question 3

Which of the following best defines a protein?

Accepted Answer

A polymer of amino acids linked by peptide bonds

Question 4

Which level of protein structure is directly responsible for the biological function of a protein?

Accepted Answer

Primary structure

Question 5

Which of the following is NOT a type of secondary structure found in proteins?

Accepted Answer

Disulfide bridge

Question 6

During the digestion of proteins in the human body, which reaction occurs first?

Accepted Answer

Hydrolysis

Question 7

Which of the following statements about denaturation is TRUE?

Accepted Answer

Denaturation disrupts secondary, tertiary, and quaternary structures, causing the protein to unfold.

Question 8

Which factor is LEAST likely to cause protein denaturation?

Accepted Answer

Mild agitation at room temperature

Question 9

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of a reaction without being changed themselves.

Question 10

The active site of an enzyme is best described as:

Accepted Answer

The region where the substrate binds and the reaction occurs

Question 11

Which model describes the substrate binding to an enzyme as a flexible fit?

Accepted Answer

Induced-fit model

Question 12

Which of the following best explains why only some proteins require quaternary structure to be active?

Accepted Answer

Quaternary structure is only needed when a protein is composed of multiple polypeptide chains.

Question 13

Which of the following is a correct statement about peptide bonds?

Accepted Answer

Peptide bonds are formed between the amine group of one amino acid and the carboxylic acid group of another.

Question 14

A patient is exposed to mercury, a heavy metal. What effect is most likely to occur to their proteins?

Accepted Answer

Mercury will cause denaturation by disrupting tertiary and quaternary structures.

Question 15

Which of the following is TRUE regarding enzyme inhibitors?

Accepted Answer

Competitive inhibitors bind to the active site and can be overcome by increasing substrate concentration.

Question 16

Which of the following factors will generally INCREASE enzyme activity?

Accepted Answer

Increasing substrate concentration up to a certain point

Question 17

Collagen is an example of which type of protein based on function?

Accepted Answer

Structural protein

Question 18

A protein is exposed to high heat and unfolds, losing its biological activity. Which structures are disrupted?

Accepted Answer

Secondary, tertiary, and quaternary structures

Question 19

Which equation best represents the hydrolysis of a peptide bond?

Accepted Answer

$$\mathrm{R_1${-}CO{-}NH{-}R_2$} + H_2O \rightarrow \mathrm{R_1${-}COOH} + \mathrm{R_2${-}NH_2$}$$

Question 20

A scientist is studying an enzyme-catalyzed reaction. She adds a molecule that binds to the enzyme at a site other than the active site, causing the enzyme to change shape and lose activity. Which type of inhibition is this?

Accepted Answer

Noncompetitive inhibition

Amino Acids, Proteins, and Enzymes: Study Guide

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