Question 1

Which of the following best describes the general chemical formula for a monosaccharide such as glucose?

Accepted Answer

$\mathrm{C}_n\mathrm{H}_{2n}\mathrm{O}_n$

Question 2

Which type of glycosidic linkage is found in maltose, and what is its significance for human digestion?

Accepted Answer

$\alpha$-1,4 linkage; it can be digested by human enzymes

Question 3

A patient is diagnosed with lactose intolerance. Which enzyme is deficient, and what type of glycosidic bond does this enzyme break?

Accepted Answer

Lactase; breaks $\beta$-1,4 glycosidic bonds

Question 4

Which polysaccharide is primarily used for energy storage in animals, and what type of linkage does it predominantly contain?

Accepted Answer

Glycogen; $\alpha$-1,4 and $\alpha$-1,6 linkages

Question 5

Which structural polysaccharide is found in the exoskeletons of insects and crustaceans, and what is its main chemical feature?

Accepted Answer

Chitin; contains $\beta$-1,4 linkages and N-acetylglucosamine units

Question 6

Which of the following best explains why cellulose is considered dietary fiber and cannot be digested by humans?

Accepted Answer

Humans lack enzymes to break $\beta$-1,4 glycosidic linkages in cellulose

Question 7

Which of the following is a function of oligosaccharides attached to proteins or lipids on the plasma membrane?

Accepted Answer

Cell recognition and signaling

Question 8

Which statement best describes the amphipathic nature of phospholipids?

Accepted Answer

They have hydrophilic heads and hydrophobic tails

Question 9

How does the presence of unsaturated fatty acids in phospholipids affect the fluidity of the plasma membrane?

Accepted Answer

Increases fluidity due to kinks preventing tight packing

Question 10

Which of the following best describes the role of cholesterol in the plasma membrane at physiological temperature ($37^\circ$C)?

Accepted Answer

Restricts excessive motion of phospholipids, maintaining optimal fluidity

Question 11

A cell is placed in a hypertonic solution. What will happen to the cell and why?

Accepted Answer

It will shrink because water moves out to the region of higher solute concentration

Question 12

Which type of membrane protein spans the entire lipid bilayer and is involved in transport?

Accepted Answer

Integral (transmembrane) protein

Question 13

Which process requires energy input to move solutes against their concentration gradient?

Accepted Answer

Active transport

Question 14

Which of the following is true about secondary active transport?

Accepted Answer

It uses the gradient created by primary active transport to move another substance

Question 15

Which of the following best describes osmosis?

Accepted Answer

The diffusion of water across a selectively permeable membrane from low to high solute concentration

Question 16

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

Accepted Answer

Simple diffusion does not require membrane proteins, while facilitated diffusion does

Question 17

A plant cell is placed in a hypotonic solution. What is the expected outcome and why?

Accepted Answer

The cell becomes turgid as water enters, but the cell wall prevents bursting

Question 18

Which of the following is a real-world example of membrane transport involving both primary and secondary active transport?

Accepted Answer

Glucose uptake in intestinal cells using the sodium-glucose symporter

Question 19

Which of the following statements about the fluid mosaic model of the plasma membrane is correct?

Accepted Answer

Membrane proteins and lipids can move laterally within the bilayer

Carbohydrates, Lipids, and Plasma Membrane Structure: Study Notes for General Biology

Study Guide - Practice Questions