chapter 5

Question 1

Define Catalyst

Answer 1

A substance that increases the rate of chemical reaction and is not changed by the reaction.
Reusable
Only small amounts needed

Question 2

Define Enzymes

Answer 2

Proteins that function as biological catalyst

Question 3

Describe why enzymes are important in all living organisms

Answer 3

Enzymes are catalyst that speed up the rate of reaction without being changed or used up in the reaction

Question 4

Describe enzyme action

Answer 4

• Enzymes are specific to 1 particular substrate
• Substrate with complimentary shape can fit into active site of enzyme forming enzyme-substrate complex.
• lock and key mechanism

Question 5

describe the properties of enymes

Answer 5

1. proteins
2. catalyst
3. work best in specific pH and temperature
4. specific ( with one type of substrate binding to one enzyme )

Question 6

describe the effect of temperature on enzymes

Answer 6

1. Enzymes work best at optimum temperature ( 37degrees )
   2.Temperatures above optimum will break the bonds that hold the enzyme together, and enzymes will denature. The active site changes shape and substrate can not fit into enzymes. Rate of reaction decreases.
2. At low temperature, kinetic energy is lower so lesser collisions between enzyme and substrate, less enzyme-substrate complex formed, rate of enzyme activity is low

Question 7

Describe the effect of pH on enzyme

Answer 7

If pH is too low or high
bonds in protein will break
changing shape of active site
Substrate cannot fit into site
less enzyme-substrate complex and products formed
reducing rate of activity

Optimum pH-7