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

A molecule of water ($$\mathrm{H_2O}) is $$considered a polar molecule. Which property of water is directly related to its polarity?

Accepted Answer

Its ability to dissolve many ionic and polar substances.

Question 3

An atom has a total of 6 electrons. How many electrons are in its inner shell and how many are in its valence shell?

Accepted Answer

2 in the inner shell, 4 in the valence shell

Question 4

Which of the following elements are always present in organic compounds?

Accepted Answer

Carbon and hydrogen

Question 5

What is the correct formula for calculating pH?

Accepted Answer

$$\mathrm{pH} = -\log[H^+]$$

Question 6

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

Accepted Answer

Covalent bond

Question 7

A chemical reaction in a cell that breaks down complex molecules into simpler ones and releases energy is called:

Accepted Answer

Catabolism (decomposition reaction)

Question 8

Which of the following best describes a salt in chemistry?

Accepted Answer

A substance that dissociates into cations and anions, neither of which is $$\mathrm{H^+} or$$ $$\mathrm{OH^-}$$

Question 9

Which of the following macromolecules is formed by dehydration synthesis with glycosidic bonds?

Accepted Answer

Carbohydrates

Question 10

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

Accepted Answer

Amino group ($$\mathrm{-NH_2$})$$

Question 11

Which of the following statements about phospholipids is correct?

Accepted Answer

They have both hydrophobic and hydrophilic regions.

Question 12

Which level of protein structure is defined by the sequence of amino acids in a polypeptide chain?

Accepted Answer

Primary structure

Question 13

Which of the following is NOT a component of a nucleotide?

Accepted Answer

A lipid molecule

Question 14

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

Accepted Answer

Saturated fats have no double bonds between carbon atoms; unsaturated fats have one or more double bonds.

Question 15

Which of the following statements about DNA is correct?

Accepted Answer

DNA consists of two strands of nucleotides wound in a double helix held together by hydrogen bonds between purine and pyrimidine nucleotides.

Question 16

Which chemical reaction type involves both synthesis and decomposition components?

Accepted Answer

Exchange reaction

Question 17

Which of the following is a property of water that is crucial for life?

Accepted Answer

Water acts as a temperature buffer due to hydrogen bonds absorbing heat.

Question 18

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

Accepted Answer

Enzymes lower the activation energy required for reactions to occur.

Question 19

Which of the following statements about pH is correct?

Accepted Answer

Increasing $$[H^+]$$ increases acidity, while increasing $$[OH^-]$$ increases alkalinity.

Question 20

Which of the following is true regarding the structure of nucleic acids?

Accepted Answer

A nucleotide consists of a pentose sugar, a phosphate group, and a nitrogen-containing base.

Chapter 2: The Chemistry of Microbiology – Study Notes

Study Guide - Practice Questions