Question

How is the activity of enzyme affected by pH and temperature?

Answer 1

Enzymes

♦Enzymes are proteins with catalytic property that speed up the rate of biochemical reactions by decreasing the activation energy !!

Factors Affecting Enzyme Activity :

✔ The Activity of the Enzymes can be affected by a change in the conditions which alter the tertiary structure of the protein (Enzymes are proteins).

✔ These include temperature, pH , change in the substrate concentration or binding of specific chemicals that regulate it's activity.


Affect of pH and temperature on the activity of an enzyme :

✴ Generally, enzymes function in a narrow range of temperature and pH .

✴ Each Enzyme shows its highest activity at a particular temperature and pH , called the optimum temperature and optimum pH.

✴ Activity of the Enzyme declines both below and above the optimum value.

✴Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat .

✴ Enzymes are active only when optimum pH is provided.

▶Ex: Pepsin (acidic medium) , Trypsin (basic medium)

Answer 2

Answer:

Affect of pH

Changes in pH may not only affect the shape of an enzyme but it may also change the shape or charge properties of the substrate so that either the substrate connot bind to the active site or it cannot undergo catalysis. In geneal enzyme have a pH optimum. However the optimum is not the same for each enzyme.

Affect of temperature

Temperature affects the reaction rate of enzymes, as do pH, substrate concentration and enzyme concentration. At low temperatures, enzymes have low activity. As the temperature rises the rate of reaction increases, usually 2-fold for every 10 degree Celsius rise.