B1.6,7,8 Movement Of Substances Into And Out Of Cells

Question 1

B1.9 Active transport

Answer 1

The movement of substances from an area of low concentration to an area of higher concentration.

Question 2

Energy for active transport

Answer 2

Energy os needed for active transport. This energy is produced during cell respiration

Question 3

B1.6 Diffusion

Answer 3

The movement of substances from an area of high concentration to an area of low concentration.

E.g. oxygen molecules diffuse from the lungs into the blood stream.

Question 4

Rates of diffusion

Answer 4

If there os a big difference in concentration between 2 areas, diffusion will take place quickly

However, if there is only a small difference in concentration between 2 areas, the net movement by diffusion will be quite slow

Question 5

B1.7,8 Osmosis

Answer 5

the movement of water molecules from an area of high concentration to an area of low concentration

across a partially permeable membrane.

Question 6

Why is osmosis needed

Answer 6

osmosis is stabilising the internal environment of an organism by keeping the water and intercellular fluids levels balanced