What does the term 'enzyme' mean? What conditions affect an enyme's activity?

• An enzyme is a biological catalyst

• Perform chemical reactions by lowering the activation energy (could then draw out energy diagram)

• Form enzyme-substrate complexes to then form enzyme-product complexes (e.g. with pepsin the substrate is a protein and the product is single amino acids)

• High temperature decreases activity (enzymes are proteins so denature at high temperatures)

• Inhibitors decrease activity

• Non-optimal pH decreases activity (due to denaturing of the protein structure)

If the student fully understands all of these concepts, we could move onto drawing out graphs of enzyme activity vs condition (e.g. temperature). We could also move onto describing and comparing the 'lock and key' and 'induced fit' models.