Transport Across Cell Membranes

Question 1

What is diffusion?

Answer 1

The passive movement of molecules down a concentration gradient from a region of high concentration to a region of lower concentration

Question 2

What is osmosis?

Answer 2

The passive movement of water molecules down a concentration gradient from a region of high water concentration to a region of lower concentration

Question 3

What is active transport?

Answer 3

Active transport is the movement of molecules from a region of low concentration to a region of high concentration requiring energy

Question 4

Give a situation where something requires active transport

Answer 4

In the sodium potassium pump in the nerve cells

Question 5

What happens when an animal cell is placed in a solution with a water concentration higher than the cells contents?

Answer 5

The water is taken by osmosis and bursts

Question 6

What happens when an animal cell is placed in a solution of lower water concentration than the cells contents?

Answer 6

Water will be lost by osmosis and the cell shrinks

Question 7

Name two substances found in cell membranes

Answer 7

Phospholipid molecules

Protein molecule/carrier

Question 8

Give two passive processes which substances pass through membranes

Answer 8

Osmosis

Diffusion

Question 9

What is the difference between an active process and a passive process?

Answer 9

Passive doesn’t require energy and active does

Question 10

What does turgid mean?

Answer 10

A swollen plant cell with a full vacuole from water intake from osmosis

Question 11

What does plasmolysed mean?

Answer 11

A description of a plant cell where the vacuole has shrunk and the membrane is pulled away from the wall due to water loss