$$pH = -\log(1 \times 10$$^{-5}$$) = 5$$

Question 1

Which of the following statements best explains why water is considered a 'universal solvent' in biological systems?

Accepted Answer

Water is a polar molecule, allowing it to dissolve many ionic and polar substances.

Question 2

A sodium atom (Na) loses one electron to become a sodium ion (Na⁺). What type of chemical reaction is this, and what is the resulting charge?

Accepted Answer

Oxidation; positive charge

Question 3

Which of the following best describes the difference between an ionic bond and a covalent bond?

Accepted Answer

Ionic bonds involve the transfer of electrons from one atom to another, while covalent bonds involve the sharing of electrons.

Question 4

Which of the following functional groups is found in all amino acids and is responsible for their acidic properties?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 5

A solution has a hydrogen ion concentration of $$[H^+] = 1 	imes 10$$^{-5}$$ M. What is the pH of this solution?

Accepted Answer

$$pH = -\log(1 	imes 10$$^{-5}$$) = 5$$

Question 6

Which property of water explains why ice floats on liquid water?

Accepted Answer

Water is less dense as a solid than as a liquid.

Question 7

Which of the following macromolecules is correctly matched with its monomer?

Accepted Answer

Carbohydrate – Monosaccharide

Question 8

Which of the following best describes a dehydration synthesis reaction?

Accepted Answer

A reaction that forms polymers from monomers by removing water.

Question 9

Which of the following statements about phospholipids is correct?

Accepted Answer

They are composed of glycerol, two fatty acids, and a phosphate group.

Question 10

Which of the following is a correct pairing of a disaccharide and its component monosaccharides?

Accepted Answer

Maltose: glucose + glucose

Question 11

Which of the following best explains why proteins denature at high temperatures?

Accepted Answer

High temperatures disrupt hydrogen bonds and other interactions, altering the protein's tertiary and secondary structure.

Question 12

Which of the following is a property of a base?

Accepted Answer

Dissociates into one or more $$OH^-$$ ions and a cation

Question 13

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

Accepted Answer

The sequence of amino acids in a polypeptide chain

Question 14

Which of the following is a correct statement about nucleic acids?

Accepted Answer

DNA contains deoxyribose and thymine.

Question 15

Which of the following is a trace element essential for life, as shown in the pie chart of human body composition?

Accepted Answer

Magnesium

Question 16

Which of the following best describes the role of hydrogen bonds in water?

Accepted Answer

They form between the hydrogen atom of one water molecule and the oxygen atom of another, giving water its unique properties.

Question 17

Which of the following organic molecules is correctly matched with its function?

Accepted Answer

Phospholipids – cell membrane structure

Question 18

Which of the following best describes the difference between a saturated and an unsaturated fatty acid?

Accepted Answer

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

Question 19

Which of the following best explains why ATP is considered the energy currency of the cell?

Accepted Answer

ATP contains high-energy phosphate bonds that, when broken, release energy for cellular processes.

Chemical Principles in Microbiology: Structure and Function of Atoms, Molecules, and Macromolecules

Study Guide - Practice Questions