Slides in this set

Slide 1

Preview of page 1

GCSE AQA Biology B3
Chapter 1
Exchange of materials
Tasneem Aiar…read more

Slide 2

Preview of page 2

Active Transport
· Diffusion is the movement of a fluid across a
concentration gradient.
· osmosis is the movement of water across a semi-
permeable membrane.
· Active transport is the cells moving substances
from a low concentration to a high
concentration. They move against a
concentration gradient…read more

Slide 3

Preview of page 3

The cells need energy in order to carry the
substances across the membrane. It is obtained
from cellular respiration also they have a lot of
mitochondria to provide it with energy.…read more

Slide 4

Preview of page 4

Gaseous exchange
· Lungs are separated from the digestive organs by
a diaphragm.
When you breathe in...
your ribs move UP and OUT
your diaphragm flattens
air is pulled INTO the lungs
When you breathe out...
your ribs move DOWN and IN
your diaphragm returns to itsdomed shape
air is forced OUT OF the lungs…read more

Slide 5

Preview of page 5

Alveolus (singular of Alveoli) allow the highest
rate of gas exchange in the lungs due to:
· large surface area
· moist surface
· thin 1 cell thick walls
· good bloody supply…read more

Slide 6

Preview of page 6

The Human Gut
· Villi allows the highest rate of diffusion because
· Large surface area
· Good blood supply
· Moist surface
· Thin 1 cell thick wall…read more

Slide 7

Preview of page 7
Preview of page 7

Slide 8

Preview of page 8
Preview of page 8

Slide 9

Preview of page 9
Preview of page 9


No comments have yet been made

Similar Biology resources:

See all Biology resources »