Question 1

Which of the following statements best describes the difference between a physical and a chemical change in matter?

Accepted Answer

A chemical change alters the basic nature of a substance, while a physical change does not.

Question 2

Which four elements make up approximately 96% of the human body’s mass?

Accepted Answer

Oxygen, Carbon, Hydrogen, Nitrogen

Question 3

An atom has 11 protons, 12 neutrons, and 11 electrons. What is its atomic number and mass number?

Accepted Answer

Atomic number: 11, Mass number: 23

Question 4

What is the primary reason that atoms form chemical bonds?

Accepted Answer

To achieve stability by interacting with other atoms’ electrons

Question 5

Which type of bond is responsible for the surface tension of water and the formation of intramolecular bonds in proteins?

Accepted Answer

Hydrogen bond

Question 6

A molecule of oxygen gas ($$\mathrm{O}_2) is $$formed by which type of chemical bond?

Accepted Answer

Double covalent bond

Question 7

Which of the following best describes a buffer’s function in the human body?

Accepted Answer

Buffers regulate pH changes by neutralizing excess acids or bases.

Question 8

If a solution has a pH of 5, how does its hydrogen ion concentration compare to a solution with a pH of 7?

Accepted Answer

It has 100 times more hydrogen ions.

Question 9

Which process involves the removal of a water molecule to join monomers into polymers?

Accepted Answer

Dehydration synthesis

Question 10

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

Accepted Answer

Digestion of food molecules into smaller units

Question 11

Which carbohydrate is classified as a polysaccharide and serves as a storage product in humans?

Accepted Answer

Glycogen

Question 12

Which of the following statements about lipids is correct?

Accepted Answer

Lipids are insoluble in water but soluble in other lipids.

Question 13

Trans fats are associated with which health risk?

Accepted Answer

Increased risk of heart disease

Question 14

Which structural feature distinguishes phospholipids from triglycerides?

Accepted Answer

Phospholipids have a phosphorus-containing polar head and two fatty acid chains.

Question 15

Which level of protein structure is characterized by a compact, ball-like (globular) shape?

Accepted Answer

Tertiary structure

Question 16

What is the main function of enzymes in biological systems?

Accepted Answer

Enzymes increase the rate of chemical reactions.

Question 17

Which nucleotide base is found in RNA but not in DNA?

Accepted Answer

Uracil

Question 18

Adenosine triphosphate (ATP) releases energy for cellular processes by breaking which bond?

Accepted Answer

The bond between the second and third phosphate groups

Question 19

Which of the following best describes the relationship between DNA and RNA?

Accepted Answer

RNA is created from a template of DNA and carries out DNA’s instructions for protein synthesis.

Question 20

A patient’s blood pH drops from 7.4 to 6.4. By what factor has the hydrogen ion concentration increased?

Accepted Answer

It has increased by a factor of 100.

Chapter 2: Basic Chemistry – Essentials of Human Anatomy & Physiology

Study Guide - Practice Questions