Enzymes Biological catalyst – it speeds up reactions without being permanently changed

Activation Energy Substrates have some energy within their chemical bonds They need extra energy added to cause them to change into products. This is called activation energy. Enzymes lower the energy needed for a reaction to occur. After the reaction, the products have less available energy than was in the original substrate

Mode of action active site specific form enzyme-substrate complexes There are two theories on how they work:

Lock and Key Hypothesis

Induced Fit Hypothesis

Factors affecting the rate of enzyme controlled reactions Enzyme Concentration Substrate Concentration Temperature pH

Inhibitors Two types: Competitive Non-competitive