Ionic bond is broken; Na\textsuperscript{+} and Cl\textsuperscript{–} ions are formed

Question 1

Which of the following is NOT one of the four major groups of biomolecules found in the human body?

Accepted Answer

Minerals

Question 2

Electrons play several important roles in physiology. Which of the following is NOT one of their four major roles?

Accepted Answer

Acting as structural support for proteins

Question 3

Using the electron dot models of hydrogen and oxygen, which of the following best describes the covalent bonding in a water molecule?

Accepted Answer

Each hydrogen shares one electron with oxygen, forming two single covalent bonds

Question 4

Which property is characteristic of polar molecules?

Accepted Answer

They dissolve easily in water

Question 5

Which of the following is a property of nonpolar molecules?

Accepted Answer

They are generally insoluble in water

Question 6

When sodium chloride (NaCl) dissolves in water, what type of bond is broken and what type of ions are formed?

Accepted Answer

Ionic bond is broken; Na	extsuperscript{+} and Cl	extsuperscript{–} ions are formed

Question 7

Cations have a __________ charge; anions have a __________ charge.

Accepted Answer

positive; negative

Question 8

How are hydrogen bonds formed?

Accepted Answer

By the attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom

Question 9

Which property of water is a direct result of hydrogen bonding?

Accepted Answer

High boiling point

Question 10

Van der Waals forces are best described as:

Accepted Answer

Weak, nonspecific interactions between atoms due to fluctuating electron clouds

Question 11

Which of the following best contrasts hydrophilic and hydrophobic interactions?

Accepted Answer

Hydrophilic molecules interact with water; hydrophobic molecules avoid water

Question 12

Which molecular shape is most likely to result in a protein functioning as an enzyme?

Accepted Answer

Globular

Question 13

An acid is a molecule that contributes $H^+$ to a solution. Which of the following is a base?

Accepted Answer

A molecule that decreases $H^+$ concentration

Question 14

Which equation correctly represents the equilibrium constant ($K_{eq}$) for a reversible reaction $A + B \rightleftharpoons C + D$?

Accepted Answer

$K_{eq} = \frac{[C][D]}{[A][B]}$

Question 15

The law of mass action states that:

Accepted Answer

The rate of a chemical reaction is proportional to the product of the concentrations of the reactants

Question 16

How does the dissociation constant ($K_d$) relate to the affinity between a ligand and a protein?

Accepted Answer

A low $K_d$ indicates high affinity

Question 17

Which of the following best describes an agonist?

Accepted Answer

A molecule that binds to a receptor and activates it

Question 18

Isoforms are important in protein function because:

Accepted Answer

They are variants of proteins that can have different binding properties

Question 19

Which statement best describes the role of cofactors in protein activation?

Accepted Answer

Cofactors are non-protein molecules required for protein function

Question 20

Which of the following factors can affect protein structure and function?

Accepted Answer

Temperature and pH

Question 21

Saturation in protein-ligand binding occurs when:

Accepted Answer

All available binding sites are occupied by ligands

Molecules, Bonds, and Protein Interactions in Anatomy & Physiology

Study Guide - Practice Questions