AP Biology Unit 2 Review

Front

What factors affect the rate of diffusion?

Back

Molecular size, temperature, solution density, and distance traveled affect diffusion. Larger molecules move slower, temperature influences molecular movement, density is inversely proportional to movement, and greater distance slows diffusion.

Front

What is the role of proteins in the plasma membrane?

Back

Proteins can be found on the surface or embedded within the plasma membrane, playing roles in transport, signaling, and structural support.

Front

How do the membranes of organelles differ from the plasma membrane?

Back

The proportions of proteins, lipids, and carbohydrates vary among different membranes, including those of organelles like mitochondria.

Front

What is the principal driving force behind diffusion?

Back

The concentration gradient is the main driving force in diffusion, causing substances to move from areas of high concentration to low concentration.

Front

Why is active transport necessary across plasma membranes?

Back

Active transport must function continuously because diffusion can move solutes in opposite directions, requiring energy to maintain concentration gradients.

Front

Define diffusion.

Back

Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a process where molecules pass through the plasma membrane via special proteins, without the use of energy.

Front

What is the function of cholesterol in the plasma membrane?

Back

Cholesterol helps to stabilize the fluidity of the plasma membrane, making it less permeable to very small water-soluble molecules.

Front

What are glycolipids and their function?

Back

Glycolipids are lipids with carbohydrate chains that play a role in cell recognition and signaling.

Front

What is selective permeability?

Back

Selective permeability is the property of a membrane that allows certain molecules to pass while blocking others.