Question 1

Which of the following statements best explains why water is considered an excellent solvent in biological systems?

Accepted Answer

Water is a polar molecule, allowing it to interact with and dissolve other polar and ionic substances.

Question 2

A patient receives a radioactive isotope for diagnostic imaging. Which property of radioisotopes makes them useful for this purpose?

Accepted Answer

They emit energy in the form of radiation, which can be detected by imaging equipment.

Question 3

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

Accepted Answer

A covalent bond involves sharing electrons between atoms, while an ionic bond involves the attraction between oppositely charged ions.

Question 4

Which equation correctly represents the reversible buffer reaction that helps maintain blood pH?

Accepted Answer

$$\mathrm{$$HCO_3$$^- + H^+ \leftrightarrow H_2CO_3}$$

Question 5

A solution has a hydrogen ion concentration of $$[H^+] = 1 	imes 10$$^{-4}$$ M. What is its pH?

Accepted Answer

$$4$$

Question 6

Which of the following is a correct statement about the structure of DNA?

Accepted Answer

DNA is double-stranded, with adenine pairing with thymine and guanine pairing with cytosine.

Question 7

Which process is responsible for breaking down macromolecules into their monomer subunits in cells?

Accepted Answer

Hydrolysis

Question 8

A triglyceride molecule is composed of which of the following components?

Accepted Answer

One glycerol molecule and three fatty acids

Question 9

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes speed up chemical reactions without being altered or consumed.

Question 10

Which of the following best explains why water helps regulate body temperature in humans?

Accepted Answer

Water absorbs and holds a large amount of heat energy with only a modest increase in temperature.

Question 11

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

Accepted Answer

Energy storage and structural support

Question 12

Which of the following elements makes up the largest percentage of body weight in humans?

Accepted Answer

Oxygen

Question 13

Which type of chemical bond is responsible for the weak attraction between water molecules?

Accepted Answer

Hydrogen bond

Question 14

A molecule of ATP releases energy when which of the following occurs?

Accepted Answer

A phosphate group is removed from ATP

Question 15

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

Accepted Answer

Saturated fatty acids contain only single bonds between carbons, while unsaturated fatty acids contain one or more double bonds.

Question 16

Which of the following is NOT a component of a nucleotide found in nucleic acids?

Accepted Answer

A fatty acid tail

Question 17

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

Accepted Answer

Buffers minimize changes in pH by accepting or donating hydrogen ions.

Question 18

Which of the following is a correct example of a disaccharide and its monosaccharide components?

Accepted Answer

Lactose: glucose + galactose

Question 19

Which of the following statements about phospholipids is TRUE?

Accepted Answer

Phospholipids have both hydrophilic and hydrophobic regions, making them ideal for forming cell membranes.

Question 20

Which of the following best describes the flow of genetic information in cells?

Accepted Answer

DNA — RNA — Proteins

Chapter 2: The Chemistry of Living Things – Study Notes

Study Guide - Practice Questions