Enzymes are biological catalysts, they speed up chemical reactions in the body. Enzymes are large protein molecules with very specific shapes. The special shape, the active site, fits with another molecule, the substrate. The shape of the enzyme is vital for it to function.
Enzymes are used for:
- Building large molecules from smaller ones
- Changing one molecule to another
- Breaking down large molecules into smaller ones (digestion)
Once an enzyme's temperature is above 37°C, the optimal temperature, its active site changes shape and the enzyme substrate complex can no longer be formed. The enzyme denatures.
If the Ph. Is wrong the forces holding the protein molecules together is affected. This changes the shape of the active site too.
Different enzymes work at different pH levels.
Enzymes do not change chemical reactions, they only catalyse them.
Enzymes activity is affected by: