Question 1

Which of the following statements best explains why carbon is uniquely suited to form large, complex, and diverse molecules essential for life?

Accepted Answer

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

Question 2

Which of the following best describes a dehydration (condensation) reaction in the synthesis of a polymer?

Accepted Answer

A water molecule is removed, forming a new covalent bond between two monomers.

Question 3

Which of the following is a correct comparison between starch and cellulose?

Accepted Answer

Starch is composed of α-glucose monomers, while cellulose is composed of β-glucose monomers.

Question 4

A molecule with the formula $$C_{6}H$$_{12}$$O_{6}$ can be classified as which of the following?

Accepted Answer

A monosaccharide

Question 5

Which of the following best describes the structure and function of phospholipids in biological membranes?

Accepted Answer

They have two hydrophobic fatty acid tails and a hydrophilic phosphate head, forming a bilayer in water.

Question 6

Which of the following is true about the difference between cis and trans fatty acids?

Accepted Answer

Trans fatty acids have hydrogen atoms on opposite sides of the double bond, resulting in a straighter chain.

Question 7

A single amino acid substitution in the primary structure of hemoglobin leads to sickle-cell disease. This is an example of how:

Accepted Answer

A change in primary structure can alter the protein’s overall shape and function.

Question 8

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 9

Which of the following statements about nucleic acids is correct?

Accepted Answer

DNA is usually double-stranded and contains thymine, while RNA is single-stranded and contains uracil.

Question 10

Which of the following best describes the process of hydrolysis?

Accepted Answer

It breaks a covalent bond in a polymer by adding a water molecule.

Question 11

Which of the following is a correct statement about isomers?

Accepted Answer

Cis-trans isomers differ in the arrangement of atoms around a double bond.

Question 12

Which of the following best explains why cellulose cannot be digested by humans?

Accepted Answer

Humans lack the enzymes to hydrolyze the β-1,4-glycosidic linkages in cellulose.

Question 13

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

Accepted Answer

Storing genetic information

Question 14

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

Accepted Answer

The association of two or more polypeptide chains into a functional protein.

Question 15

Which of the following statements about lipids is correct?

Accepted Answer

Lipids are hydrophobic molecules that include fats, phospholipids, and steroids.

Question 16

Which of the following best explains the role of cholesterol in animal cell membranes?

Accepted Answer

It maintains membrane fluidity and serves as a precursor for steroid hormones.

Question 17

Which of the following is a correct pairing of a functional group and its property?

Accepted Answer

Carboxyl group ($$-COOH$$): acts as an acid

Question 18

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

Accepted Answer

DNA → RNA → Protein

Question 19

Which of the following is a real-world application of hydrolysis in the human body?

Accepted Answer

Digestion of dietary starch into glucose monomers in the small intestine

Chapter 3: Carbon and the Molecular Diversity of Life – Study Notes

Study Guide - Practice Questions