Question 1

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

Accepted Answer

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

Question 2

Which functional group is found in both proteins and lipids and is essential for forming fatty acids?

Accepted Answer

Carboxyl group (–COOH)

Question 3

A triglyceride is formed by which type of reaction between glycerol and fatty acids?

Accepted Answer

Dehydration reaction

Question 4

Which of the following statements about saturated and unsaturated fatty acids is correct?

Accepted Answer

Saturated fatty acids have the maximum number of hydrogen atoms and no double bonds.

Question 5

Which of the following best describes the amphipathic nature of phospholipids?

Accepted Answer

They have both hydrophilic and hydrophobic regions.

Question 6

Cholesterol is classified as which type of lipid, and what is its primary structural feature?

Accepted Answer

Steroid; four fused hydrocarbon rings

Question 7

Which of the following molecules would have the highest chemical potential energy based on bond type?

Accepted Answer

A molecule with many C–H bonds

Question 8

Why are lipids insoluble in water?

Accepted Answer

They are composed mostly of nonpolar hydrocarbon chains.

Question 9

Which of the following is NOT a function of the plasma membrane?

Accepted Answer

Storing genetic information

Question 10

A scientist discovers a lipid molecule with two fatty acid tails, a glycerol backbone, and a phosphate group. What is the primary biological role of this molecule?

Accepted Answer

Forming cell membranes

Question 11

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

Accepted Answer

Their hydrocarbon chains have kinks due to double bonds, preventing tight packing.

Question 12

Which of the following is a correct comparison between carbohydrates and fats regarding their chemical structure and energy content?

Accepted Answer

Fats have more C–H bonds and thus more chemical potential energy than carbohydrates.

Question 13

Which of the following is a real-world example of the amphipathic property of phospholipids?

Accepted Answer

Soap molecules forming micelles to trap grease in water

Question 14

Which of the following best describes the role of cholesterol in animal cell membranes?

Accepted Answer

It modulates membrane fluidity and stability.

Question 15

Which of the following statements about the chemical evolution of lipids is supported by evidence?

Accepted Answer

Modern meteorites contain simple lipids such as fatty acids.

Question 16

A mutation causes a cell to produce phospholipids with only one fatty acid tail. Which of the following is the most likely consequence for the cell membrane?

Accepted Answer

The membrane would not form a stable bilayer, compromising cell integrity.

Question 17

Which of the following best explains why fats are a more efficient form of energy storage than carbohydrates?

Accepted Answer

Fats have more C–H bonds, which store more chemical energy.

Question 18

Which of the following is a correct description of an ester linkage in a fat molecule?

Accepted Answer

A bond formed between a hydroxyl group of glycerol and a carboxyl group of a fatty acid, releasing water.

Question 19

Which of the following best describes the difference between a steroid and a fat?

Accepted Answer

Steroids have a four-ring structure, while fats are composed of three fatty acids linked to glycerol.

Lipids, Membranes, and the First Cells: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard