$$[H^+] = 1 \times 10$$^{-3}$$ M

Question 1

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

Accepted Answer

Water's polarity allows it to dissolve many ionic and polar substances by forming hydration spheres.

Question 2

A patient presents with a blood pH of 7.28. Which condition does this indicate, and what is the physiological significance?

Accepted Answer

Acidosis; the blood is too acidic, which can disrupt enzyme function and protein structure.

Question 3

Which of the following elements is most abundant in the human body by weight and is essential for respiration?

Accepted Answer

Oxygen

Question 4

What type of chemical bond is primarily responsible for holding together the two strands of DNA?

Accepted Answer

Hydrogen bonds

Question 5

Which of the following best describes the process of dehydration synthesis in the formation of a disaccharide?

Accepted Answer

A water molecule is removed to form a bond between two monosaccharides.

Question 6

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

Accepted Answer

Providing insulation and energy storage

Question 7

A solution has a pH of 3. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-3}$$ M

Question 8

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to occur more rapidly.

Question 9

Which of the following best describes the structure of a nucleotide?

Accepted Answer

A sugar, a phosphate group, and a nitrogenous base

Question 10

Which of the following is a physiological role of sodium ions ($$Na^+) in $$the human body?

Accepted Answer

Important for blood volume, nerve impulses, and muscle contraction

Question 11

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil molecules are non-polar and do not interact with polar water molecules.

Question 12

Which of the following is true regarding the formation of a peptide bond?

Accepted Answer

It is formed by dehydration synthesis, releasing a molecule of water.

Question 13

Which of the following organic molecules is primarily responsible for storing genetic information?

Accepted Answer

Nucleic acids

Question 14

A patient is experiencing muscle cramps and irregular nerve impulses. Which electrolyte imbalance is most likely responsible?

Accepted Answer

Low levels of $$Na^+ or$$ $$K^+$$

Question 15

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

Accepted Answer

Saturated fatty acids have no double bonds; unsaturated fatty acids have one or more double bonds.

Question 16

Which of the following is a correct example of a polysaccharide and its function in the human body?

Accepted Answer

Glycogen; storage form of glucose in muscles and liver

Question 17

Which of the following best describes the role of buffers in the human body?

Accepted Answer

Buffers maintain the pH of body fluids by removing or replacing hydrogen ions.

Question 18

Which of the following is a correct pairing of a steroid and its function?

Accepted Answer

Cholesterol; component of plasma membranes

Question 19

Which of the following best explains why enzymes are necessary for life?

Accepted Answer

They lower the activation energy, allowing reactions to occur at body temperature.

Question 20

Which of the following is a purine found in nucleic acids?

Accepted Answer

Adenine

The Chemical Level of Organization: Study Notes for Human Anatomy & Physiology I

Study Guide - Practice Questions