$$[H^+] = 1 \times 10$$^{-5}$$ M

Question 1

Which of the following best describes the difference between atomic number and atomic weight?

Accepted Answer

Atomic number is the number of protons in an atom, while atomic weight is the average mass of an element’s atoms, including isotopes.

Question 2

A sodium atom (Na) reacts with a chlorine atom (Cl) to form sodium chloride (NaCl). Which type of bond is formed, and what happens to the electrons?

Accepted Answer

An ionic bond is formed; sodium donates an electron to chlorine.

Question 3

Which of the following molecules is most likely to be soluble in water and why?

Accepted Answer

Glucose, because it contains polar covalent bonds.

Question 4

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy required for a reaction, allowing reactions to occur at normal body temperature.

Question 5

A solution has a pH of 5. What is the concentration of hydrogen ions ($$[H^+]) in $$this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-5}$$ M

Question 6

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

Accepted Answer

Hydrogen bonds between water molecules must be broken before the temperature can increase.

Question 7

Which of the following is a polysaccharide stored in the human body for energy?

Accepted Answer

Glycogen

Question 8

A protein loses its three-dimensional structure due to high fever. What is this process called, and what is the consequence?

Accepted Answer

Denaturation; the protein becomes nonfunctional.

Question 9

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

Accepted Answer

Saturated fatty acids have only single covalent bonds between carbons; unsaturated fatty acids have one or more double bonds.

Question 10

Which of the following is the correct sequence of protein structural levels from simplest to most complex?

Accepted Answer

Primary, secondary, tertiary, quaternary

Question 11

Which class of biological molecules is responsible for storing genetic information and directing protein synthesis?

Accepted Answer

Nucleic acids

Question 12

A buffer system in the blood helps maintain pH within a narrow range. What is the main function of a buffer?

Accepted Answer

To stabilize pH by removing or replacing hydrogen ions ($$H^+)$$

Question 13

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond where electrons are shared unequally, resulting in partial charges on the molecule.

Question 14

Which of the following is a real-life example of hydrolysis?

Accepted Answer

Breaking down starch into glucose molecules during digestion.

Question 15

Which of the following statements about phospholipids is correct?

Accepted Answer

They have a hydrophilic head and two hydrophobic tails, making them essential for cell membrane structure.

Question 16

Which of the following best explains why cellulose cannot be digested by humans?

Accepted Answer

Humans lack the enzyme needed to break the bonds in cellulose.

Question 17

Which of the following is a function of proteins in the human body?

Accepted Answer

All of the above (support, transport, enzyme activity, defense)

Question 18

Which of the following best describes the role of cholesterol in the body?

Accepted Answer

It is a component of cell membranes and a precursor for steroid hormones.

Question 19

Which of the following is true about the structure of a nucleotide?

Accepted Answer

It consists of a sugar, a phosphate group, and a nitrogenous base.

Question 20

Which of the following best explains why enzymes are considered catalysts?

Accepted Answer

They accelerate chemical reactions without being permanently changed.

Chemical Level of Organization: Study Notes for Anatomy & Physiology

Study Guide - Practice Questions