Question 1

Which of the following best explains why water is considered the most abundant inorganic compound in living cells?

Accepted Answer

It accounts for 60%-80% of the volume of living cells and has unique properties such as high heat capacity and polar solvent abilities.

Question 2

A patient is suffering from heat stroke. Which property of water is most directly responsible for the body's ability to cool itself through sweating?

Accepted Answer

High heat of vaporization

Question 3

Which of the following statements about electrolytes is correct?

Accepted Answer

Electrolytes are ions that can conduct electrical currents in solution.

Question 4

A solution has a hydrogen ion concentration of $$[H^+] = 10$$^{-4}$$ M. What is its pH, and is it acidic, neutral, or basic?

Accepted Answer

pH = 4; the solution is acidic.

Question 5

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

Accepted Answer

Dehydration synthesis builds polymers from monomers by removing water, while hydrolysis breaks polymers into monomers by adding water.

Question 6

Which of the following is a correct example of a disaccharide and its formation?

Accepted Answer

Glucose + Glucose → Maltose + Water

Question 7

A food label lists 'partially hydrogenated oils' as an ingredient. What type of fat is most likely present, and what is a health implication?

Accepted Answer

Trans fat; increases risk of cardiovascular disease

Question 8

Which structural feature distinguishes phospholipids from triglycerides and is critical for their function in cell membranes?

Accepted Answer

Phospholipids have a polar phosphate-containing head and two nonpolar fatty acid tails, making them amphipathic.

Question 9

Which of the following best explains why proteins can have such a wide variety of functions in the body?

Accepted Answer

Proteins are composed of 20 different amino acids, which can be arranged in countless sequences and structures.

Question 10

A patient with a high fever is at risk for protein denaturation. What is the most likely consequence at the molecular level?

Accepted Answer

The protein unfolds, losing its 3-D shape and active site, which can deactivate its function.

Question 11

Which of the following best describes the specificity of enzyme action?

Accepted Answer

Each enzyme has an active site that binds only specific substrates, forming an enzyme-substrate complex.

Question 12

A solution changes from pH 7 to pH 5. How does the hydrogen ion concentration change?

Accepted Answer

It increases by 100 times.

Question 13

Which of the following is a correct pairing of a nucleic acid with its function?

Accepted Answer

DNA: stores genetic information and directs protein synthesis

Question 14

Which of the following best explains why cholesterol is important in the body?

Accepted Answer

It is the starting material for synthesis of vitamin D, steroid hormones, and bile salts.

Question 15

A competitive inhibitor of an enzyme would most likely:

Accepted Answer

Bind to the active site, preventing the substrate from binding.

Question 16

Which of the following is true regarding the structure of DNA?

Accepted Answer

It is a double-stranded helix with complementary base pairing: A with T and G with C.

Question 17

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP provides immediate, usable energy for cellular work.

Question 18

Which of the following is a correct example of a polysaccharide and its biological role?

Accepted Answer

Glycogen; energy storage in animals

Question 19

A solution contains equal concentrations of $$H^+$$ and $$OH^-$$ ions. What is its pH and classification?

Accepted Answer

pH 7; neutral

Question 20

Which of the following best explains why enzymes are not considered reactants in the chemical reactions they catalyze?

Accepted Answer

Enzymes lower the activation energy but are not changed or consumed in the reaction.

Biochemistry Foundations for Anatomy & Physiology: Inorganic Compounds, Acids, Bases, and pH

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