$$ATP + H_2O \rightarrow ADP + P_i + \text{energy}$$

Question 1

Which of the following best describes the process by which amino acids are joined together to form a polypeptide in the human body?

Accepted Answer

Dehydration synthesis, which removes water to form peptide bonds between amino acids.

Question 2

A patient is unable to digest cellulose but can digest starch and glycogen. Which statement best explains this phenomenon?

Accepted Answer

Humans lack the enzyme required to break the bonds in cellulose.

Question 3

Which of the following is NOT a function of proteins in the human body?

Accepted Answer

Universal energy source for cells

Question 4

Which chemical group is found at one end of every amino acid?

Accepted Answer

An amino group ($$-NH_3$)

Question 5

How many different amino acids are used in human proteins, and how many must be obtained from the diet?

Accepted Answer

20 amino acids; 9 must be obtained from the diet

Question 6

Which statement correctly compares DNA and RNA?

Accepted Answer

DNA is double-stranded and contains deoxyribose; RNA is single-stranded and contains ribose.

Question 7

What is the role of enzymes in metabolic reactions?

Accepted Answer

Enzymes act as biological catalysts, speeding up reactions without being consumed.

Question 8

Which of the following best describes the structure of a nucleotide found in DNA?

Accepted Answer

A five-carbon sugar, a phosphate group, and a nitrogenous base

Question 9

Which equation represents the hydrolysis of ATP to release energy?

Accepted Answer

$$ATP + H_2O ightarrow ADP + P_i + 	ext{energy}$$

Question 10

A mutation causes a change in the base sequence of DNA. What is the most immediate consequence of this change?

Accepted Answer

The instructions for producing RNA may be changed.

Question 11

Which of the following is true regarding the energy stored in ATP?

Accepted Answer

Energy is stored in the bonds between the three phosphate groups.

Question 12

Which of the following is a correct pairing of nitrogenous bases in DNA?

Accepted Answer

Cytosine pairs with guanine

Question 13

A scientist isolates a nucleic acid that contains ribose sugar and uracil. What type of molecule is this?

Accepted Answer

RNA

Question 14

Which process is responsible for breaking down macromolecules into their monomer units?

Accepted Answer

Hydrolysis

Question 15

Which of the following is a direct consequence of ATP hydrolysis in a muscle cell?

Accepted Answer

Release of energy used for muscle contraction

Question 16

Which of the following statements about polypeptides is correct?

Accepted Answer

Polypeptides are chains of amino acids joined by peptide bonds.

Question 17

Which of the following best explains why enzymes are essential for life?

Accepted Answer

They allow metabolic reactions to occur at rates compatible with life.

Question 18

Which of the following is a correct description of the relationship between DNA, RNA, and proteins?

Accepted Answer

DNA contains instructions for producing RNA, which contains instructions for producing proteins.

Question 19

A polypeptide contains 150 amino acids. What is this molecule most likely called?

Accepted Answer

A protein

Question 20

Which of the following is a real-life example of enzyme specificity?

Accepted Answer

Humans can digest starch but not cellulose due to the presence or absence of specific enzymes.

Macromolecules: Proteins, Nucleic Acids & ATP (Chapter 2, Sections 2.8–2.10)

Study Guide - Practice Questions