What are enzymes?
Enzymes are biological catalysts.
A catalyst is a molecule that increases the rate (speed) of a reaction. Enzymes act as catalysts for chemical reactions in the cell.
It is unlikely glucose molecules will spontaneously form a starch molecule. The cell uses an enzyme (starch synthase) to produce starch quickly.
Like all proteins, enzymes are formed from chains of amino acids. In enzymes, the chains form a globular structure (spherical):
There are several important features of enzymes:
- Highly specific: Each enzyme only acts on a single type of reaction.
- Unchanged: Enzymes are not altered by their reactions.
- Reusable: Enzymes can be used multiple times.