CCEA GCSE BIOLOGY unit 1 notes

5000 words 20 pages
BIOLOGY NOTES.

UNIT 1: Photosynthesis

Photosynthesis Word Equation:

Light
Carbon Dioxide + Water Oxygen + Glucose Chlorophyll

How to test a leaf for starch:

1. Dip leaf boiling water for about 1 minute to soften it, stop further chemical changes and make the cell more permeable.

2. Turn off Bunsen burner.
Put the leaf into the half a test-tube of ethanol.
Stand the test-tube in the hot water for a few minutes.
(Takes green chlorophyll out of leaf)

3. Dip the leaf into water. (Softens the leaf)

4. Spread the leaf out on a white tile and cover it with iodine
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Diabetes:-
A poorly balanced diet or obesity can lead to Type 2 diabetes.
The body suffers sugar ‘overload’ and insulin stops being effective in controlling the sugar levels.

Digestion

Digestion is the breakdown of large insoluble molecules into small, soluble food molecules so that they can be absorbed into the bloodstream

Starch Amylase Glucose
(a carbohydrate)

Protein Protease Amino Acids

Fats Lipase Fatty Acids & Glycerol

Parts of body, and functions with in digestion system:
Buccal Cavity- food is mixed with saliva, saliva contains the enzyme amylase.
Tongue- tastes and moves the food around.
Teeth- chew the food.
Epiglottis- Prevents food from getting to the lungs.
Oesophagus- Tube that connects the mouth and stomach. Has circular muscles in its wall which contract and squeeze in behind the food. This is called peristalsis.
Stomach- churns the food, mixing it with hydrochloric acid and gastric juices. Gastric juices contain protease which begins protein digestion.
Pyloric Sphincter- A ring of muscle that keeps food inside the

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