1. Life’s locks and keys Section 2.5
Biology notes

2. Enzymes
Enzymes are proteins that accelerate chemical reactions, but do not change themselves in the reactions.

3. Enzymes
Since enzymes are rather flexible structures, the active site is continually reshaped by interactions with the substrate as the substrate interacts with the enzyme.

4. Names of enzymes generally end with the suffix –ase
An example of an enzyme is amylase found in your saliva which helps to break down complex starch molecules to begin the digestion process.

5. Enzymes

6. Substrates A substrate is a molecule upon which an enzyme acts.
An example of a substrate would be milk and the enzyme added would be rennin which causes the milk to set.

7. Catalyst
A catalyst is a substance that accelerates a chemical reaction, but is not consumed by the overall reaction.

8. Catalyst
A good example of a catalyst is in the disproportion of hydrogen peroxide to give water and oxygen:
2 H2O2 → 2 H2O + O2

9. Hormones
A hormone is a chemical messenger that carries a signal from one cell to another.
The function of hormones is to carry information to the target cells.

10. Hormones
The best-known animal hormones are those produced by endocrine glands of vertebrate animals, but hormones are produced by nearly every organ system and tissue type in a multicellular organism.

11. Hormones