Question 1

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 2

A molecule of water (H$$_2O) is $$held together by which type of bond between the hydrogen and oxygen atoms?

Accepted Answer

Polar covalent bond

Question 3

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture of solute and solvent

Question 4

Which functional group is found in all amino acids and acts as a base?

Accepted Answer

Amino group

Question 5

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water is a polar molecule, so it can surround and separate ions due to its partial charges.

Question 6

Which of the following statements about acids and bases is correct?

Accepted Answer

Acids increase the hydrogen ion concentration $$[H^+] in a $$solution.

Question 7

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 8

Which of the following is a correct pairing of a purine and a pyrimidine found in DNA?

Accepted Answer

Adenine (purine) pairs with Thymine (pyrimidine)

Question 9

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

Accepted Answer

The sequence of amino acids in a polypeptide chain

Question 10

Which of the following molecules is considered organic?

Accepted Answer

Glucose (C$$_6H$_{12}O$_6)$$

Question 11

Which of the following best describes the role of ATP in living cells?

Accepted Answer

ATP stores and provides energy for cellular processes by releasing a phosphate group.

Question 12

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds are weak attractions between a hydrogen atom and an electronegative atom such as oxygen or nitrogen.

Question 13

Which of the following best describes a dehydration synthesis reaction?

Accepted Answer

A reaction in which two monomers are joined together by removing a molecule of water.

Question 14

Which of the following functional groups is responsible for the acidic properties of amino acids?

Accepted Answer

Carboxyl group

Question 15

Which of the following best explains why phospholipids are important in cell membranes?

Accepted Answer

They form a bilayer with hydrophilic heads facing outward and hydrophobic tails facing inward, creating a selective barrier.

Question 16

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

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 17

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

Accepted Answer

The overall three-dimensional shape of a single polypeptide chain, stabilized by interactions between R groups.

Question 18

Which of the following is a function of glycogen in living organisms?

Accepted Answer

It serves as a storage form of glucose in animals.

Question 19

Which of the following best describes the role of enzymes in biological systems?

Accepted Answer

Enzymes act as biological catalysts that speed up chemical reactions without being consumed.

Question 20

Which of the following statements about the pH scale is correct?

Accepted Answer

A solution with a pH of 3 has a higher concentration of $$[H^+]$$ ions than a solution with a pH of 7.

Fundamental Chemistry and Biomolecules for Microbiology

Study Guide - Practice Questions