Question 1

Which of the following statements best describes the difference between a molecule and a compound?

Accepted Answer

A molecule is two or more atoms chemically combined, while a compound is two or more atoms of different elements chemically combined.

Question 2

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

Accepted Answer

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

Question 3

A sodium atom (Na) has an atomic number of 11 and an atomic mass of 23. How many neutrons does a typical sodium atom have?

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 4

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

Accepted Answer

$$A + B \rightarrow AB$$

Question 5

What is the main reason that saturated fats are solid at room temperature while unsaturated fats are liquid?

Accepted Answer

Saturated fats have only single bonds between carbon atoms, making their chains straight and able to pack closely together.

Question 6

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

Accepted Answer

Enzymes act as biological catalysts, increasing the rate of chemical reactions by lowering the activation energy.

Question 7

A patient is experiencing a rapid drop in blood pH. Which of the following would help stabilize their pH?

Accepted Answer

Adding a buffer solution

Question 8

Which of the following is true about isotopes of an element?

Accepted Answer

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

Question 9

Which of the following best explains why water has a high heat capacity?

Accepted Answer

Water molecules form hydrogen bonds that absorb and release large amounts of heat before changing temperature.

Question 10

Which of the following is a property of a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in partial charges on the molecule.

Question 11

Which of the following best describes the structure of DNA?

Accepted Answer

A double helix formed by two polynucleotide strands held together by hydrogen bonds between complementary bases.

Question 12

Which of the following is the correct complementary DNA strand for the sequence 5'-TGCGTAAG-3'?

Accepted Answer

5'-ACGCATTC-3'

Question 13

Which of the following best describes the process of hydrolysis?

Accepted Answer

A water molecule is used to break a chemical bond in a polymer, resulting in smaller molecules.

Question 14

Which of the following is a function of phospholipids in the body?

Accepted Answer

They are the main component of cellular membranes due to their polar and nonpolar regions.

Question 15

Which of the following best explains why sodium (Na) and chlorine (Cl) form an ionic bond?

Accepted Answer

Sodium donates an electron to chlorine, resulting in oppositely charged ions that attract each other.

Question 16

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

Accepted Answer

$$AB \rightarrow A + B$$

Question 17

Which of the following is a property of an acid?

Accepted Answer

It donates protons ($$H^+) in $$solution.

Question 18

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

Accepted Answer

The sequence of amino acids in a polypeptide chain.

Question 19

Which of the following is a correct statement about ATP?

Accepted Answer

ATP stores energy in high-energy phosphate bonds and releases it when these bonds are broken.

Question 20

Which of the following best explains why buffers are important in biological systems?

Accepted Answer

Buffers help maintain a stable pH by accepting or donating $$H^+$$ ions as needed.

Basic Chemistry for Anatomy & Physiology: Structure, Bonds, and Biological Molecules

Study Guide - Practice Questions