You will need to know about the following 

Biological molecules: proteins, carbohydrates, nucleic acid, lipids

Cells: prokaryotic and eukaryotic

Cell transport: Lipid diffusion, passive & active transport, osmosis and vesicles

Organisms exchange materials with their environment and this becomes harder as the size of the organism increases

Enzymes are vital for life and are easily affected if their conditions are changed

Digestion occurs in the mouth, oesophagus, stomach, small intestine and large intestine