Question 1

Which of the following best describes the relationship between an atom’s mass number and atomic number?

Accepted Answer

The mass number is the sum of protons and neutrons, while the atomic number is the number of protons.

Question 2

A scientist is studying the effect of pH on the activity of the enzyme bromelain. If the enzyme is most active at pH 4 and is placed in a solution with pH 11, what is the most likely outcome?

Accepted Answer

The enzyme will denature and lose activity because the pH is far from its optimal range.

Question 3

Which of the following statements about water molecules is correct?

Accepted Answer

Water molecules are polar because oxygen is more electronegative than hydrogen, creating partial charges.

Question 4

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice create a lattice structure that is less dense than liquid water.

Question 5

A triglyceride is formed by the condensation of one glycerol molecule and three fatty acids. How many water molecules are produced during this reaction?

Accepted Answer

Three

Question 6

Which of the following is a correct description of a buffer system in biological fluids?

Accepted Answer

A buffer system resists changes in pH by accepting or donating hydrogen ions ($$H^+).$$

Question 7

Which of the following best describes the primary structure of a protein?

Accepted Answer

The sequence of amino acids in a polypeptide chain.

Question 8

Which of the following is a real-world example of hydrolysis?

Accepted Answer

The breakdown of starch into glucose molecules during digestion.

Question 9

A scientist observes that the average distance between sea slugs increases dramatically at 4 PM compared to other times of day. Which of the following is the most plausible biological explanation?

Accepted Answer

Sea slugs are more active and spread out to avoid competition for food during the afternoon.

Question 10

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

Accepted Answer

Unsaturated fatty acids have one or more double bonds, causing kinks in the chain, while saturated fatty acids have no double bonds.

Question 11

Which of the following is an example of a polysaccharide and its biological function?

Accepted Answer

Cellulose; provides structural support in plant cell walls.

Question 12

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water is polar, so its partial charges can surround and separate ions.

Question 13

Which of the following is a correct statement about the tertiary structure of a protein?

Accepted Answer

It is the overall 3D shape formed by interactions between R groups of amino acids.

Question 14

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

Accepted Answer

Enzymes act as catalysts, lowering the activation energy and speeding up reactions.

Question 15

A solution has a pH of 3.5. Which of the following statements is true?

Accepted Answer

The solution is acidic and has a high concentration of $$H^+$$ ions.

Question 16

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophobic tails avoid water while their hydrophilic heads interact with water.

Question 17

Which of the following is a correct example of a monomer-polymer relationship?

Accepted Answer

Amino acid: protein

Question 18

Which of the following best describes the function of a buffer in human blood?

Accepted Answer

It prevents drastic changes in pH by neutralizing excess acids or bases.

Question 19

Which of the following is a correct statement about the quaternary structure of proteins?

Accepted Answer

It is the way multiple polypeptide chains interact to form a functional protein.

Question 20

Which of the following best explains why unsaturated fats are generally liquid at room temperature?

Accepted Answer

They have kinks in their hydrocarbon chains due to double bonds, preventing tight packing.

General Biology: Foundations, Biochemistry, and Macromolecules Study Guide

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