1.4 Proteins

Amino acids

Different sequences of amino acids bid together to form different protein molecules

Forms supporting framework inside of cells and forms body structures

Speed up chemical reactions whilst remaining unchanged

To act as chemical messengers in the body

Play an important role in immune systems. Antibodies destroy micro-organisms which cause infection.

Target tissues have cells with complementary receptor proteins which specific hormones to bind to.

Protein molecules made by all living cells

Biological catalyst which speeds up cellular reactions while remaining unchanged.

A special site on an enzymes surface to enable them to speed up chemical reactions.

The shape of the active site is complementary to its specific substrates.

The molecule(s) on which the enzyme binds to and reacts with during an enzyme controlled reaction.

• The substrate binds (temporally) to the active site of the enzyme forming an enzyme-substrate complex to allow the reaction to take place. • At the end of an enzyme controlled reaction product(s) are formed and released from active site

Degradation Synthesis

Large complex molecules are broken down into smaller simpler ones by enzyme action e.g all the reactions are involved in digestion.

Small, simple molecules are built up into large, more complex ones by enzyme action, e.g glucose builds up into starch for storage plants.

hydrogen peroxide ————– water & oxygen catalase starch ————– maltose amylase

Temperature pH

Each enzyme is most active in its optimum condition, outwith its optimum conditions enzymes can become denatured meaning their active site would change shape permanently, affecting the rate of reactions.