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

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

Question 1

Which of the following best explains why water is considered an excellent solvent in biological systems?

Accepted Answer

Water is a universal solvent because it is polar and can dissolve ionic and polar substances by dissociating them into ions.

Question 2

A patient is experiencing muscle cramps due to an electrolyte imbalance. Which ions are most directly involved in nerve impulses and muscle contractions?

Accepted Answer

Sodium and potassium

Question 3

Which of the following statements about acids and bases is correct?

Accepted Answer

Acids are proton donors and release $$H^+$$ ions in solution.

Question 4

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 5

Which buffer system is most important for maintaining the pH of blood?

Accepted Answer

Carbonic acid-bicarbonate buffer system

Question 6

During dehydration synthesis, which of the following occurs?

Accepted Answer

A hydrogen atom is removed from one monomer and a hydroxyl group from another, forming water and joining the monomers.

Question 7

Which of the following is a monosaccharide?

Accepted Answer

Glucose

Question 8

If a person consumes more glucose than is needed for immediate energy, what happens to the excess glucose?

Accepted Answer

It is converted to glycogen and, if stores are full, converted to fat.

Question 9

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

Accepted Answer

One glycerol molecule bonded to three fatty acids by dehydration synthesis.

Question 10

Which type of fatty acid is most likely to be solid at room temperature and why?

Accepted Answer

Saturated fatty acids, because they have only single bonds and can pack closely together.

Question 11

Phospholipids are essential for cell membrane structure because:

Accepted Answer

Their hydrophobic tails and hydrophilic heads allow them to form bilayers in water.

Question 12

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

Accepted Answer

Catalyzing chemical reactions as enzymes

Question 13

A protein's function is determined primarily by its:

Accepted Answer

Amino acid sequence and resulting three-dimensional shape

Question 14

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

Accepted Answer

Enzymes speed up chemical reactions by lowering the activation energy.

Question 15

A solution with a pH of 8 is considered:

Accepted Answer

Alkaline (basic)

Question 16

Which of the following is true regarding the relationship between pH and hydrogen ion concentration?

Accepted Answer

A change of 1 pH unit represents a 10-fold change in $$[H^+].$$

Question 17

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

Accepted Answer

The carbonic acid-bicarbonate system, which helps resist abrupt changes in blood pH

Question 18

Which of the following best describes the difference between hydrolysis and dehydration synthesis?

Accepted Answer

Hydrolysis splits polymers into monomers by adding water, while dehydration synthesis joins monomers by removing water.

Question 19

Which of the following is a disaccharide formed by dehydration synthesis of two monosaccharides?

Accepted Answer

Sucrose

Question 20

A patient with a blood pH of 7.2 is experiencing which condition, and what buffer system will help correct it?

Accepted Answer

Acidosis; carbonic acid-bicarbonate buffer system

Biochemistry: Water, Salts, Acids, Bases, and Organic Molecules in Anatomy & Physiology

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