B3.5 Factors Affecting Enzyme Activity

Question 1

Explain why enzyme activity increases as temperature up to the optimum

Answer 1

As temperature increases up to the optimum, enzyme activity increases as well. The thermal energy provided hives the particles more kinetic energy, and more collision between the enzyme and substrate (creating an enzyme-substrate complex) so the enzymes are breaking down more.

Question 2

Explain why enzyme activity rapidly decreases with increasing temperature beyond the optimum.

Answer 2

When kinetic energy increases beyond the optimum it results in unwanted vibrations in the enzyme itself. These vibrations become so powerful that they overcome the bonds between eachother and deviate from the careful construction of the enzyme. The denatured enzymes change the shape of the active site and make it impossible to break down larger nutrients.

Question 3

Explain why enzyme activity decreases as the pH increases above / decreases below the optimum pH.

Answer 3

Enzyme activity decreases as you deviate from the optimum pH as changing the pH of its surroundings will also change the active site of the enzyme. The different hydrogen ion amounts will denature the enzyme and cause the active site to no longer connect to the substrate making an enzyme-substrate complex. This causes enzyme activity to decrease as many enzymes don’t have the active site to break down the macronutrients.