Question 1

Which property of carbon most directly explains its ability to form large, complex, and diverse molecules essential for life?

Accepted Answer

Its four valence electrons allow it to form four covalent bonds with a variety of atoms.

Question 2

A dehydration reaction is crucial in the synthesis of which type of biological molecule?

Accepted Answer

Polymers, by removing a water molecule to form a new covalent bond between monomers

Question 3

Which functional group is present in all amino acids and is responsible for their acidic properties?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 4

A patient is diagnosed with sickle-cell disease. Which molecular change is responsible for this condition?

Accepted Answer

A single amino acid substitution in the primary structure of the hemoglobin protein

Question 5

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

Accepted Answer

A phospholipid has two hydrophobic fatty acid tails and a hydrophilic phosphate head, forming a bilayer in water.

Question 6

Which of the following statements about DNA and RNA is correct?

Accepted Answer

DNA is usually double-stranded and contains deoxyribose, while RNA is usually single-stranded and contains ribose.

Question 7

Which type of bond is responsible for the primary structure of a protein?

Accepted Answer

Peptide bonds between amino acids

Question 8

A molecule of glucose ($$C_6H_{12}O_6$) is classified as which of the following?

Accepted Answer

A monosaccharide

Question 9

Which of the following best explains why fats are hydrophobic?

Accepted Answer

They consist mostly of hydrocarbons, which form nonpolar covalent bonds.

Question 10

Which of the following is a correct pairing of a polymer and its monomer?

Accepted Answer

Polysaccharide and monosaccharide

Question 11

A scientist is studying a molecule with the formula $$C_{12}H$$_{22}$$O_{11}$. This molecule is most likely:

Accepted Answer

A disaccharide

Question 12

Which of the following best describes the difference between starch and cellulose?

Accepted Answer

Both are polymers of glucose, but they differ in the type of glycosidic linkages between glucose monomers.

Question 13

Which of the following statements about ATP (adenosine triphosphate) is correct?

Accepted Answer

ATP releases energy when it reacts with water, breaking a phosphate bond.

Question 14

Which of the following best explains why unsaturated fats are liquid at room temperature?

Accepted Answer

They contain one or more double bonds, causing kinks that prevent tight packing.

Question 15

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

Accepted Answer

Storing genetic information

Question 16

A change in which level of protein structure is most likely to be caused by a mutation in the DNA sequence of a gene?

Accepted Answer

Primary structure

Question 17

Which of the following best describes the antiparallel arrangement of DNA?

Accepted Answer

The two strands of DNA run in opposite 5' to 3' directions.

Question 18

Which of the following is a correct statement about the formation of a peptide bond?

Accepted Answer

A peptide bond forms between the carboxyl group of one amino acid and the amino group of another, releasing a molecule of water.

Question 19

Which of the following best explains why denaturation of a protein can lead to loss of function?

Accepted Answer

Denaturation disrupts the three-dimensional shape required for the protein's function.

Question 20

Which of the following is a correct description of a nucleotide found in DNA?

Accepted Answer

A nucleotide consists of a deoxyribose sugar, a phosphate group, and a nitrogenous base.

Carbon and the Molecular Diversity of Life: Study Notes

Study Guide - Practice Questions