Question 1

Which of the following statements best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons.

Question 2

An atom with a total of six electrons will have how many electrons in its inner shell and how many in its valence shell?

Accepted Answer

2 in the inner shell, 4 in the valence shell

Question 3

Which elements are always present in organic compounds?

Accepted Answer

Carbon and hydrogen

Question 4

What is the correct formula for calculating pH?

Accepted Answer

$$pH = -\log[H^+]$$

Question 5

Which type of chemical bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Question 6

A molecule of water ($$H_2O) is $$considered a polar molecule because:

Accepted Answer

The electrons are shared unequally between oxygen and hydrogen atoms.

Question 7

Which of the following best describes a synthesis reaction in biological systems?

Accepted Answer

A reaction where smaller molecules combine to form a larger molecule, requiring energy input.

Question 8

Which of the following is NOT a property of water that makes it important for life?

Accepted Answer

It is hydrophobic and repels most molecules.

Question 9

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

Accepted Answer

Acids increase the concentration of $$H^+$$ ions in solution.

Question 10

Which macromolecule is formed by dehydration synthesis with glycosidic bonds?

Accepted Answer

Carbohydrates

Question 11

Which of the following is a monomer of proteins?

Accepted Answer

Amino acid

Question 12

Which type of lipid is a primary component of cell membranes?

Accepted Answer

Phospholipid

Question 13

Which of the following best describes the structure of DNA?

Accepted Answer

Two strands of nucleotides wound in a double helix held together by hydrogen bonds between purine and pyrimidine bases.

Question 14

Which of the following is a correct description of a peptide bond?

Accepted Answer

A bond formed between the amino group of one amino acid and the carboxyl group of another.

Question 15

Which of the following is true about the pH scale?

Accepted Answer

A solution with pH 3 is more acidic than a solution with pH 7.

Question 16

Which of the following is a function of enzymes in biological systems?

Accepted Answer

They speed up chemical reactions by lowering activation energy.

Question 17

Which of the following is a correct example of a decomposition reaction?

Accepted Answer

A large molecule is broken down into smaller molecules, releasing energy.

Question 18

Which of the following best describes a buffer?

Accepted Answer

A substance that helps maintain a stable pH in a solution.

Question 19

Which of the following is true about nucleic acids?

Accepted Answer

They are polymers of nucleotides.

Question 20

A charged atom that has gained or lost electrons is called:

Accepted Answer

An ion

The Chemistry of Microbiology: Basic Fundamentals and Biological Macromolecules

Study Guide - Practice Questions