Unit 1 - Transport Across Cell Membrane

Question 1

Define diffusion

Answer 1

Diffusion is the movement of water molecules from an area of high concentration to an area of low concentration, down a concentration gradient (Doesn’t require energy.)

Question 2

Importance of diffuison - Unicellular Organsms

Answer 2

-Cells require oxygen for repiration, this enters the cells by diffusion.
-They produce CO2 which is a waste product that must be removed by diffuidon.

Question 3

Importance of diffusion - Multicellular Organisms

Answer 3

-The oxygen we breathe enters our lungs and our body cells by diffusion.
- We breathe out CO2.
- Glucose travels through the body.

Question 4

Name the parts of the cell membrane.

Answer 4

• Phospholipid
• Channel protein
• Carrier protein

Question 5

Define Osmosis

Answer 5

Osmosis is the movement of water molecules from an area of higher water concentration to an area of lower water concentration, across a selectively permeable membrane.

Question 6

Hypertonic

Answer 6

Lower water concentration (sugar > water)

Question 7

Hypotonic

Answer 7

Higher water concentration (sugar < water)

Question 8

Isotonic

Answer 8

Equal water concentration (sugar = water)