Proteins

• The variety of protein shapes and functions arises from the sequence of amino acids.
• Proteins have many functions such as
  • structural
  • enzymes
  • hormones
  • antibodies
  • receptors

Protein	Function
Structural	Forms supporting frameworks inside cells and forms body structures
Enzymes	Catalyse biological reactions
Hormones	Chemical messengers that allow communication between different parts of the body.
Antibodies	Part of the immune system, defends the body against pathogens
Receptors	Found of cell membranes they bind to specific proteins such as enzymes or hormones

Enzymes

• Enzymes function as biological catalysts and are made by all living cells.
• They speed up cellular reactions and are unchanged in the process.

• The shape of the active site of an enzyme molecule is complementary to its specific substrate(s).
• An enzyme-substrate complex forms, facilitating the reaction.
• Enzyme action results in product(s).

• Enzymes can be involved in degradation and synthesis reactions.
• Degradation reactions break down larger molecules into smaller ones.
• Synthesis reactions build up smaller molecules into larger ones.

• Each enzyme is most active in its optimum conditions.
• Enzymes, and other proteins, can be affected by temperature and pH.

• Enzymes can be denatured, resulting in a change in their shape which will affect the rate of reaction.

 

Topic Summary