1. What are Enzymes?
1.1. Proteins that function as biological catalysts, to carry out metabolic processes (eg: respiration and photosynthesis)
1.1.1. Speed up chemical reactions in the cell
1.1.2. Proteins are biological molecules composed of long chains of amino acids
1.1.3. Enzymes have a 3D global shape with an active site complementary to a substrate
2. What affects Enzyme activity?
2.1. Induced Fit. The active site changes it's shape, and fits around the substrate.
2.2. The fit around the substrate causes it to put pressure on its bonds, therefore resulting in the formation of new products.
2.3. Enzymes are formed by long chains of amino acids. Under certain conditions, the bonds between them can be broken to cause the enzyme to lose its specific shape. The substrate would no longer fit. This is called denaturing.
2.3.1. Temperature also affects Enzyme activity.
2.3.1.1. At low temperatures enzymes are inactive because they lack the kinetic energy for successful collisions between the substrate, and the enzyme active site.
2.3.1.2. As the temperature increases the particles have more kinetic energy which at the optimum temperature, results in more frequent and energetic collisions between substrates and enzymes. This leads to a high rate of reaction.
2.3.1.3. The optimum temperature is the point whereafter the enzymes begin to denature due to the excess heat deforming the shape of the active site (optimum temp. for amylase is 37˚C)
2.3.2. pH levels affect Enzyme activity
2.3.2.1. Enzymes have a range of pHs in which they function. Rate of reaction is highest at the optimum pH.
2.3.2.2. At either side of the optimum pH (higher, or lower), the rate of reaction will decrease. At either side, the enzymes will begin to denature.
2.3.2.2.1. The bonds within the enzyme are disrupted, and the active site loses its specific shape. This results in the substrate no longer binding with the enzyme.