Honor Bio 9.2

Question 1

What is simple diffusion?

Answer 1

The movement of molecules from an area of higher concentration to an area of lower concentration without the need for energy.

Question 2

What is facilitated diffusion?

Answer 2

The process of passive transport of molecules across a membrane via specific transmembrane integral proteins.

Question 3

Define osmosis.

Answer 3

The diffusion of water across a selectively permeable membrane.

Question 4

What does hypertonic mean?

Answer 4

A solution that has a higher concentration of solutes compared to another solution.

Question 5

What does hypotonic mean?

Answer 5

A solution that has a lower concentration of solutes compared to another solution.

Question 6

Define isotonic.

Answer 6

A solution that has the same concentration of solutes as another solution.

Question 7

What is active transport?

Answer 7

The movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, using energy.

Question 8

What is endocytosis?

Answer 8

The process by which cells internalize substances by engulfing them in a membrane.

Question 9

What is exocytosis?

Answer 9

The process by which cells expel materials in vesicles that fuse with the cell membrane.

Question 10

List the properties and structure of phospholipids.

Answer 10

• Composed of a hydrophilic (water-attracting) head
• Two hydrophobic (water-repelling) tails
• Form bilayers in aqueous environments
• Essential for cell membrane structure.

Question 11

Identify parts of the cell membrane.

Answer 11

• Phospholipids
• Cholesterol
• Proteins
• Carbohydrates

Each component plays a role in membrane fluidity, structure, and function.

Question 12

What is the importance of the surface area: volume ratio?

Answer 12

It affects the rate of exchange of materials between the cell and its environment; higher ratios facilitate better exchange.

Question 13

Compare and contrast different types of transport.

Answer 13

• Simple diffusion: moves small, nonpolar molecules, down concentration gradient, no energy, no transport proteins
• Facilitated diffusion: moves larger or polar molecules, down concentration gradient, no energy, requires transport proteins
• Active transport: moves molecules against concentration gradient, requires energy, requires transport proteins.

Question 14

Predict which way solutes will diffuse across a membrane.

Answer 14

Solutes will diffuse from an area of higher concentration to an area of lower concentration.

Question 15

Predict which way water will diffuse across a membrane via osmosis.

Answer 15

Water will diffuse toward the area of higher solute concentration.