Question 1

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

Accepted Answer

The hydrophilic phosphate heads interact with water, while the hydrophobic fatty acid tails avoid water, resulting in a bilayer structure.

Question 2

A mutation causes a cell membrane protein to lose its ability to form hydrogen bonds. Which of the following is the most likely consequence?

Accepted Answer

The protein may lose specificity in binding to other molecules, such as DNA or substrates.

Question 3

Which of the following best describes the role of Van der Waals forces in protein folding?

Accepted Answer

They stabilize protein folding by providing weak, transient attractions between atoms.

Question 4

A patient is found to have a genetic disorder that disrupts the function of their cytoskeleton. Which of the following symptoms would most likely be observed?

Accepted Answer

Impaired cell division and abnormal chromosome segregation during mitosis.

Question 5

Which of the following statements about membrane proteins is correct?

Accepted Answer

Integral proteins are tightly bound to the membrane and can only be removed by disrupting the membrane structure.

Question 6

A researcher adds a strong acid to a protein solution, causing the pH to drop significantly. What is the most likely effect on the protein structure?

Accepted Answer

The protein will denature due to disruption of hydrogen and ionic bonds.

Question 7

Which of the following best describes the function of membrane carbohydrates?

Accepted Answer

They attach to proteins and lipids, playing a role in cell recognition and immune response.

Question 8

A cell is placed in a solution that causes its membrane proteins to lose their tertiary structure. Which of the following is the most likely result?

Accepted Answer

The function of membrane proteins, such as transporters and receptors, will be lost.

Question 9

Which of the following is a correct statement about the molecular arrangement of the cell membrane?

Accepted Answer

The membrane is a fluid mosaic of lipids and proteins, with proteins embedded or attached to the lipid bilayer.

Question 10

Which of the following best explains why cholesterol is important in cell membranes?

Accepted Answer

Cholesterol helps make membranes impermeable to small water-soluble molecules and keeps membranes flexible over a range of temperatures.

Question 11

A scientist observes that a certain membrane protein can move laterally within the membrane but cannot flip from one side to the other. Which property of the membrane does this illustrate?

Accepted Answer

The membrane is fluid, allowing lateral movement of proteins but restricting transverse movement.

Question 12

Which of the following best describes the function of micelles in the digestive tract?

Accepted Answer

Micelles aid in the digestion and absorption of fats by arranging phospholipids so that their hydrophobic tails are sequestered from water.

Question 13

Which of the following is a function of the cytoskeleton?

Accepted Answer

It helps maintain cell shape and assists in the movement of organelles.

Question 14

A cell is observed to have a high ratio of protein to lipid in its membrane. Which of the following is the most likely explanation?

Accepted Answer

The cell is highly metabolically active, such as a mitochondrion, requiring many proteins for ATP production.

Question 15

Which of the following best describes the role of buffers, such as bicarbonate in blood, in physiological systems?

Accepted Answer

Buffers stabilize pH, allowing proteins to remain intact for proper enzymatic activity.

Question 16

A drug is designed to bind to a membrane protein via noncovalent interactions. Which type of chemical bond is most likely involved in this binding?

Accepted Answer

Hydrogen bonds

Question 17

Which of the following best explains why temperature shifts can lead to protein denaturation?

Accepted Answer

Temperature shifts disrupt hydrogen and ionic bonds, altering protein structure.

Question 18

Which of the following is a correct statement about the function of membrane glycoproteins?

Accepted Answer

They play a key role in cell recognition and immune response.

Question 19

A cell is observed to have inclusions in direct contact with the cytosol. Which of the following best describes these inclusions?

Accepted Answer

They are particles of insoluble material, such as glycogen granules or lipid droplets, not separated from the cytosol by a membrane.

Cell Membrane Structure and Chemical Bonds: Foundations for Anatomy & Physiology

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