Explain the effects of factors (pH, temperature and inhibitor)on the rate of enzymatic reactions.
The effect of pH towards enzymatic reaction
👆🏻This photo showing the effect of pH towards the rate of enzymatic reaction.
- Different enzyme has different optimum pH range that the changing of pH out of the optimum pH range will slow down enzymatic reaction.
- Enzyme work best in optimal pH that the rate of enzymatic reaction is the highest.
- In extreme pH enzyme may denature that rate of enzymatic reaction will decline.
- e.g. Pepsin - digest protein in stomach so work best in acidic condition .
- e.g. salivary amylase - digest starch in the mouth work best in neutral condition.
- e.g. Arginase - catalyse the formation of urea work best in alkaline condition.
The effect of temperature towards enzymatic reaction
In HKDSE Biology examination, students will be asked to draw the graph showing the effect of temperature towards the rate of enzymatic reaction with elaboration ❗️ ❕
👆🏻This photo showing the effect of temperature towards the rate of enzymatic reaction.
- At low temperature, the rate of enzymatic reaction is low as enzyme is inactive.
- The rate of reaction keep on increasing due to the increase of temperature favour the collision.
- At optimal temperature, the rate of enzymatic reaction is the highest as enzyme work best in this temperature.
- At high temperature, the rate of enzymatic reaction is low as enzyme is denatured.
The effect of inhibitor towards enzymatic reaction
In HKDSE Biology examination, you only have to know one kind of inhibitor - competitive inhibitor ❗️ ❕
👆🏻This photo showing the effect of inhibitor towards the rate of enzymatic reaction.
1. Competitive inhibitor
- Competitive inhibitor is inhibitor that will bind to the active site of enzyme and preventing the formation of enzyme-substrate complex.
- Inhibitor compete with substrate for the active site of enzyme.
- 🔺Incresing the concentration of enzyme can eliminate the effect of competitive inhibitor ❗️ ❕
👆🏻This photo showing how competitive inhibitor affect the rate of enzymatic reaction.
1. Non-competitive inhibitor
- Non-competitive inhibitor Competitive inhibitor is inhibitor that will not bind to the active site of enzyme but acttach to the other side of enzyme that cause the changes on active site of enzyme.
- Inhibitor doesn't compete with substrate for the active site of enzyme.
- 🔺Incresing the concentration of enzyme can not eliminate the effect of non-competitive inhibitor ❗️ ❕
👆🏻This photo showing how non-competitive inhibitor affect the rate of enzymatic reaction.
That's the end of this topic 👏🏻
References
- Enzymes review (article) | Enzymes. (n.d.). Retrieved from https://www.khanacademy.org/science/high-school-biology/hs-energy-and-transport/hs-enzymes/a/hs-enzymes-review
- Enzyme regulation (article). (n.d.). Retrieved from https://www.khanacademy.org/science/biology/energy-and-enzymes/enzyme-regulation/a/enzyme-regulation