AQA Biology B3- Exchange of Materials, Breathing and the Circulatory System

A powerpoint outlining all the facts you need to know for a large proportion of the B3 unit of AQA GCSE Biology, part one.

HideShow resource information

Slides in this set

Slide 1

Preview of page 1

AQA Biology GCSE- B3 Unit
Breathing and the circulatory
By Rachel
[email protected]…read more

Slide 2

Preview of page 2

The Exchange of Materials
· ACTIVE TRANSPORT= the movement of a
substance against a concentration gradient.
Uses up energy from respiration, and is found in
the intestines and the kidney (for absorption and
· DIFFUSION= the random net movement of
particles from high concentration to a low one
across a partially permeable membrane
· OSMOSIS= the diffusion of water…read more

Slide 3

Preview of page 3

The Intestine
· VILLI= tiny protrusions in the intestine which
help to absorb the products of digestion
· Use active transport to gain as much of the
valuable materials, especially sugar, as possible
· Villi help increase absorption because they:
­ Have a large surface area
­ Are moist
­ Are very close to a large network of capillaries
(absorbed straight into blood stream)…read more

Slide 4

Preview of page 4

The Breathing System
· Breath out= ribcage down, diaphragm up
· Breath in= ribcage up, diaphragm down
Air moves in the mouth, down the trachea, down a bronchi, down into
the bronchioles and into the alveoli.
ALVEOLI= tiny air sacs in the lungs well adapted to gaseous exchange
1. They create a large surface area
2. They are moist
3. They have very thin walls- less distance for gases to travel
4. The constant movement of the blood and the breathing of the lungs
keeps a high concentration gradient perfect for diffusion
5. The blood capillaries are right next to the alveoli, meaning easy
access for the oxygen to diffuse into the blood, and the CO2 into the
lungs.…read more

Slide 5

Preview of page 5

The Circulatory System
· Oxygenated blood is pumped to the heart from the lungs, and to the body from the
· De-oxygenated blood is pumped from the heart to the lungs, and from the body
back to the heart
· VEINS= carry blood to the heart
· ARTERIES= carry blood away from the heart
· CAPILLARIES= tiny blood vessels found near organs and tissues of the body that
exchange substances with the cells eg glucose, CO2
Right side= pumps low O2 blood to lungs & back
Left side= pumps high O2 blood to body & back
Key Vocab to research: Ventricle, Atrium, Valves... You'll need to know the workings of
the heart... there are plenty of good diagrams of the heart on google images!
Click Here!…read more

Slide 6

Preview of page 6

· WHITE BLOOD CELLS- fight infection
· PLATELETS- help blood to clot
· PLASMA- holds dissolved substances, glucose (taken
from the small intestine to the body organs), CO2, waste
products (urea from the kidneys)
­ No nucleus- more room for gas
­ Special shape with a lowered centre- greater surface area to
absorb gas
­ HAEMOGLOBIN- substance which gains oxygen from the lungs
to form OXYhaemoglobin. Then releases oxygen into cells.…read more

Slide 7

Preview of page 7
Preview of page 7


No comments have yet been made

Similar Biology resources:

See all Biology resources »