Question 1

Which of the following statements best explains why lipids are not considered true polymers, unlike carbohydrates, proteins, and nucleic acids?

Accepted Answer

Lipids are not composed of monomers linked by covalent bonds.

Question 2

A student adds Benedict's reagent to an unknown solution and heats it. The solution turns red-orange. What does this indicate about the unknown solution?

Accepted Answer

It contains a large amount of reducing sugars.

Question 3

Which of the following best describes the process of dehydration synthesis?

Accepted Answer

The removal of a water molecule to link two monomers together, requiring enzymes and energy.

Question 4

Which macromolecule is primarily responsible for information storage in living organisms?

Accepted Answer

Nucleic acids

Question 5

A dialysis bag filled with a starch solution is placed in pure water. After 30 minutes, Lugol's reagent is added to the water outside the bag and no color change is observed. What is the most likely explanation?

Accepted Answer

Starch molecules are too large to pass through the semipermeable membrane.

Question 6

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

Accepted Answer

They decrease the activation energy $$ (E_A) $$ required for the reaction.

Question 7

A solution is tested with Biuret's reagent and turns bright purple. What does this indicate?

Accepted Answer

Proteins are present in the solution.

Question 8

Which of the following is a correct comparison between facilitated diffusion and active transport?

Accepted Answer

Facilitated diffusion moves molecules down their concentration gradient without energy, while active transport moves molecules against their gradient using ATP.

Question 9

Which of the following best explains why cells are typically small in size?

Accepted Answer

A small cell has a higher surface area-to-volume ratio, allowing for more efficient diffusion of materials.

Question 10

Which of the following is NOT a monomer of carbohydrates?

Accepted Answer

Amino acid

Question 11

A scientist is studying the effect of temperature on the enzyme catalase. She observes that at high temperatures, the amount of oxygen released from hydrogen peroxide decreases. What is the most likely explanation?

Accepted Answer

High temperatures denature the enzyme, altering its active site and reducing its activity.

Question 12

Which of the following best describes the function of the sodium-potassium pump in cells?

Accepted Answer

It uses ATP to move sodium and potassium ions against their concentration gradients.

Question 13

Which of the following is a correct statement about hydrolysis?

Accepted Answer

Hydrolysis adds a water molecule to break a covalent bond between two monomers, releasing energy.

Question 14

Which of the following is a function of proteins in living organisms?

Accepted Answer

Aiding chemical reactions as enzymes

Question 15

A solution is tested with Sudan IV reagent and forms an orange layer separated from water. What does this indicate?

Accepted Answer

Lipids are present in the solution.

Question 16

Which of the following best describes the 'lock and key' model of enzyme function?

Accepted Answer

The enzyme's active site is specifically shaped to fit only its substrate.

Question 17

Which of the following elements is NOT a major component of proteins?

Accepted Answer

Phosphorus

Question 18

Which of the following scenarios best illustrates the effect of an enzyme inhibitor?

Accepted Answer

A molecule binds to an enzyme, changing its shape so the substrate can no longer bind.

Question 19

Which of the following best describes the movement of water when a cell is placed in a hypertonic solution?

Accepted Answer

Water moves out of the cell, causing it to shrink.

Question 20

Which of the following is a correct statement about nucleotides?

Accepted Answer

They are the monomers that make up nucleic acids such as DNA and RNA.

Organic Molecules, Cell Membranes, and Enzyme Function: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards