Science Revision - Enzymes and Sports Drinks

What are enzymes?

Enzymes are biological catalysts. They speed up chemical reactions in all living things, and allow them to occur more easily. They occur in plant cells and animal cells. Without them we would not be alive.

Enzymes are just chemical molecules, made up of proteins.

Each particular enzyme has a unique, 3-dimensional shape shared by all its molecules. Within this shape there is an area called the active site where the chemical reactions occur.

What do enzymes do?

Some enzymes help to break down large molecules.

Others build up large molecules from small ones.

While many others help turn one molecule into another.

Probably the fastest enzyme known is called catalase. It breaks the chemical hydrogen peroxide down to water and oxygen. Catalase is found in all cells and protects them from this dangerous waste chemical.

Optimum conditions

Each type of enzyme has its own specific optimum condition under which it works best.

Enzymes work best when they have a high enough substrate concentration for the reaction they catalyse. If too little substrate is available the rate of the reaction is slowed and cannot increase any further.

The pH must be correct for each enzyme. If the conditions are too alkaline or acidic then the activity of the enzyme is affected. This…