$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following statements best explains why carbon is able to form such a wide variety of molecules essential for life?

Accepted Answer

Carbon has four valence electrons, allowing it to form up to four covalent bonds with a variety of atoms.

Question 2

A molecule with the formula $$C_6H_{12}O_6$ is classified as which type of biomolecule?

Accepted Answer

Carbohydrate

Question 3

Which of the following best describes the difference between a dehydration reaction and a hydrolysis reaction?

Accepted Answer

Dehydration reactions build polymers by removing water, while hydrolysis reactions break polymers by adding water.

Question 4

Which of the following is a structural polysaccharide found in the exoskeletons of arthropods and the cell walls of fungi?

Accepted Answer

Chitin

Question 5

A patient is diagnosed with sickle-cell disease. Which of the following best explains the molecular basis of this disorder?

Accepted Answer

A single amino acid substitution in the primary structure of hemoglobin alters its function.

Question 6

Which of the following best describes the structure of a phospholipid and its role in biological membranes?

Accepted Answer

A phospholipid has two fatty acid tails and a phosphate group, forming a bilayer with hydrophobic tails inside and hydrophilic heads outside.

Question 7

Which of the following functional groups is responsible for the negative charge and energy transfer properties of ATP?

Accepted Answer

Phosphate group ($$-$$OPO_3$$^{2-})$$

Question 8

Which of the following statements about isomers is correct?

Accepted Answer

Structural isomers have the same molecular formula but different covalent arrangements of their atoms.

Question 9

Which of the following best explains why cellulose cannot be digested by most animals, while starch can?

Accepted Answer

Cellulose has $$\beta-1$$,4 glycosidic linkages, which most animals lack enzymes to hydrolyze, while starch has $$\alpha-1$$,4 linkages.

Question 10

A sample of an unknown macromolecule is found to contain the elements C, H, O, N, and S. Which class of biomolecule is it most likely to be?

Accepted Answer

Protein

Question 11

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 12

Which of the following is true about the structure of DNA?

Accepted Answer

DNA consists of two antiparallel strands forming a double helix, with complementary base pairing between adenine and thymine.

Question 13

Which of the following best explains why fats store more energy per gram than carbohydrates?

Accepted Answer

Fats have long hydrocarbon chains with many nonpolar covalent bonds, which store more energy.

Question 14

Which of the following is a correct pairing of a nitrogenous base with its complementary base in DNA?

Accepted Answer

Adenine pairs with thymine

Question 15

A researcher is analyzing a sample and finds a molecule with a long hydrocarbon chain and a carboxyl group at one end. This molecule is most likely:

Accepted Answer

A fatty acid

Question 16

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

Accepted Answer

The overall three-dimensional shape of a polypeptide resulting from interactions among R groups

Question 17

Which of the following is NOT a function of proteins in living organisms?

Accepted Answer

Storing genetic information

Question 18

Which of the following best explains why trans fats are considered unhealthy?

Accepted Answer

They have trans double bonds, which can increase LDL cholesterol and risk of heart disease.

Question 19

Which of the following statements about nucleotides is correct?

Accepted Answer

Nucleotides are composed of a nitrogenous base, a pentose sugar, and a phosphate group.

Carbon and the Molecular Diversity of Life: Structure and Function of Biomolecules

Study Guide - Practice Questions