Movement through Cell Membranes

Question 1

What is osmosis?

Answer 1

The movement of water molecules from an area of high concentration to a region of low concentration across a semi-permeable layer.

Question 2

What is diffusion?

Answer 2

The passive movement of particles from a region of high concentration to a region of low concentration.

Question 3

Diffusion is a type of passive transport. What does this mean?

Answer 3

No energy is required for it to occur.

Question 4

(3 points)

What is crenation?

Answer 4

• If animal cells are placed in a solution with a high amount of dissolved soutes, then they are said to be osmotically challenged.
• Water will leave the cell by osmosis.
• This process is known as crenation.

Question 5

What does it mean to be selectively permeable?

Answer 5

Membranes can choose to allow or block materials to enter or exit a cell.

Question 6

What is turgor?

Answer 6

The pressure of the contents of a cell against its cell wall. Applies to any organism with a cell wall.

Question 7

What is plasmolysis?

Answer 7

The process of water loss from a plant cell.

Question 8

How is salt and sugar used to preserve food?

Answer 8

If microorganisms land on foods preserved with sugar or salt, such as jams or meats, they will lose water by osmosis, shrivel up and die.

Question 9

How does turgor aid a cell?

Answer 9

Turgor helps to maintain the shape of the cell.

Question 10

What is turgidity?

Answer 10

Turgidity is a condition in which the contents of the cell are exerting a pressure on the cell wall, such that the cell wall will not expand anymore.

Question 11

How does lack of turgor occur in a cell?

Answer 11

Lack of turgor occurs when a cell with a cell wall loses water by osmosis.