Question 1

Which of the following best describes the main finding of Miller's 1953 experiment?

Accepted Answer

Demonstrated that simple organic molecules could be synthesized from inorganic precursors under conditions simulating early Earth.

Question 2

Which of the following is NOT one of the four major classes of biomolecules?

Accepted Answer

Vitamins

Question 3

A molecule with the functional group $$-\mathrm{COOH} is $$classified as which of the following?

Accepted Answer

Carboxyl group

Question 4

Which element is considered a major essential element for life?

Accepted Answer

Nitrogen (N)

Question 5

Which of the following best describes the difference between a cation and an anion?

Accepted Answer

A cation has a positive charge; an anion has a negative charge.

Question 6

Which of the following ions is most important for nerve impulse transmission in the human body?

Accepted Answer

Sodium ($$\mathrm{Na^+})$$

Question 7

Which of the following statements about covalent bonds is correct?

Accepted Answer

Covalent bonds involve the sharing of electron pairs between atoms.

Question 8

A solution is made by dissolving table salt in water. In this scenario, which is the solute and which is the solvent?

Accepted Answer

Salt is the solute; water is the solvent.

Question 9

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 10

Which of the following best explains why oil and water do not mix?

Accepted Answer

Oil is non-polar and water is polar, so they do not form favorable interactions.

Question 11

Which of the following equations correctly defines pH?

Accepted Answer

$$\mathrm{pH} = -\log_{10}[\mathrm{H}^+]$$

Question 12

A solution has a hydrogen ion concentration of $$1 	imes 10$$^{-7}$$ M. What is its pH?

Accepted Answer

pH = 7

Question 13

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

Accepted Answer

Catalyzing biochemical reactions

Question 14

Which of the following best describes the concept of protein-ligand specificity?

Accepted Answer

A protein binds only to a particular ligand due to complementary shape and chemical properties.

Question 15

Which factor can increase the rate of a chemical reaction in the body by lowering the activation energy?

Accepted Answer

Enzyme (catalyst)

Question 16

A competitive inhibitor affects an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 17

Which of the following best describes the Law of Mass Action as it applies to protein-ligand binding?

Accepted Answer

The rate of binding is proportional to the concentrations of both protein and ligand.

Question 18

Which of the following is a correct example of a non-covalent interaction?

Accepted Answer

Hydrogen bond between water molecules

Question 19

Which of the following best explains why magnesium ($$\mathrm{Mg$$^{2+}$$}) is $$considered an essential element for life?

Accepted Answer

It acts as a cofactor for many enzymes, stabilizing structures and participating in catalysis.

Question 20

A patient is found to have a blood pH of 7.1. Which of the following best describes this condition?

Accepted Answer

Acidosis

Chapter 2: Biomolecules, Chemical Principles, and Protein Function in Physiology

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