Enzymes B1

Question 1

What are enzymes?

Answer 1

Enzymes are biological catalysts that speed up the rate of chemical reactions.

Question 2

What happens to enzymes when temperature is increased?

Answer 2

At first, the enzyme activity is increased as molecules have more kinetic energy therefore more successful and frequent collisions. However high temperatures start to break bonds holding the enzyme together so the active site starts to change shape. If it changes shape enough the substrate won’t be able to bind to the active site - meaning it has denatured.

Question 3

What is the optimum temperature?

Answer 3

The optimum temperature is where the rate of reaction is the highest (the ideal temperature). It is usually 37°C.

Question 4

What happens to enzymes when pH levels are changed?

Answer 4

Too low or too high pH levels will slow the rate of reaction as some bonds holding the enzyme start to break, so the active site starts to change slightly but the substrate can still fit just worst, this slows down the rate of reaction.

Question 5

What happens to enzymes when enzyme and substrate concentration is increased?

Answer 5

The more enzyme molecules there are, the more likely a substrate will meet up with one and join with the it, increasing the rate of reaction, however as substrates are limited the rate will begin to plateau when every substrate is binded to an enzyme.