Membrane Proteins, Diffusion, and Osmosis: Understanding Movemen

Which of the following membrane proteins is responsible for signal transduction?

• Channel protein

• Carrier protein

• Receptor protein

• Glycoprotein

A plant cell is placed in a concentrated sucrose solution. Which of the following best describes what will happen?

• It becomes turgid

• It undergoes plasmolysis

• It bursts

• No net movement of water occurs

Which factor increases the rate of simple diffusion across a membrane?

• Larger molecule size

• Greater membrane thickness

• Lower temperature

• Steeper concentration gradient

What is the main role of cholesterol in the cell membrane?

• Facilitates active transport

• Forms channels for ions

• Stabilizes membrane fluidity

• Acts as a receptor

Refer to the diagram on the left showing a membrane and various transport types.
Which one represents facilitated diffusion?

• 1

• 2

• 3

• 4

Which molecule is least likely to cross a phospholipid bilayer via simple diffusion?

• Oxygen

• Water

• Glucose

• Carbon dioxide

Which property makes phospholipids form bilayers in water?

• Their polar fatty acid tails

• Their hydrophilic phosphate heads and hydrophobic tails

• Their size and charge

• Their interaction with cholesterol

Which process does not require membrane proteins?

• Facilitated diffusion

• Osmosis

• Active transport

• Endocytosis

Why is the surface area to volume ratio important in cells?

• It affects mitosis

• It determines the DNA content

• It influences the efficiency of diffusion

• It increases ATP production

A red blood cell is placed in distilled water. What will most likely occur?

• The cell shrinks

• The cell remains unchanged

• The cell bursts

• The cell becomes crenated