2.4 Effects of Local Conditions on Enzyme Activity [HY]

Question 1

Which enzymatic activities the same thing?

Answer 1

• enzyme activity, enzyme velocity, and enzyme rate

Question 2

How are enzymes velocities affected by temperature?

Answer 2

• tend to double in velocity for every 10°C increase in temperature until the optimum temperature is reached
• After optimum temp. may denature, but may regain function if cooled

Question 3

How does pH affect enzymes?

Answer 3

• enzymes also depend on pH in order to function properly
• changes in pH can lead to denaturation of the enzyme
• pH affects the ionization of the active site

Question 4

What is physiological pH and how does it differ with enzymes?

Answer 4

• Optimal pH is 7.4 for all enzymes except 2
• exceptions are in the digestive tract. Pepsin, which works in the stomach, has maximal activity around pH 2, whereas pancreatic enzymes, which work in the small intestine, work best around pH 8.5.

Question 5

How does salt affect enzymes in vitro?

Answer 5

• can disrupt hydrogen and ionic bonds, causing a partial change in the conformation of the enzyme, and in some cases causing denaturation