Abiology student is studying digestive systems, and the particular chemicals released by organisms to break food down into a digestible form. it appears that the chemical released to break down carbohydrates (c is different to the chemical released to break down proteins (p. the student is interested in the effect of chemicals p and c on digestion, and the interaction of these two chemicals.

Salivary amylase
- produced in the mouth
- an enzyme that breaks down long strands of starch molecules into maltose.

Pepsin
- an enzyme that breaks down proteins into smaller peptide
- produced by stomach ; activated by stomach acid

Enzymes produced by the pancreas
Pancreatic proteases - help to digest proteins.
Pancreatic amylase - helps to digest sugars (carbohydrates).
Pancreatic lipase - helps to digest fat.

The troposphere gets warmer as altitude increases.