MINISTRY OF EDUCATION
SECONDARY ENGAGEMENT PROGRAMME
INTEGRATED SCIENCE
GRADE 9
Week 7
Lesson - Worksheet
Topic: Enzymes
Instruction: Answer All Questions
1. Describe the following key words:
Enzyme
Substrate
Active site
2. Identify the active site, enzyme, and substrate.
A
B
C
3. Explain in your own words the importance of enzymes.
4. Outline four characteristics of enzymes.
Read the paragraph to answer Question 5.
Jane and Smith are in the lab conducting an experiment titled “Enzymes”. They are using bread,
milk, sausage, iodine solution, biuret solution and amylase as their materials. Each sample is
placed into a separate petri dish. They are prepared and iodine solution is dropped onto the bread
which turns blue-black. Biuret solution is dropped onto the milk and sausage which slowly turns
purple. A fresh sample is placed in clean Petri dishes and amylase is dropped onto each. After
ten minutes the iodine solution is dropped onto the bread and biuret solution onto the milk and
sausage. At the end of the experiment they only noticed that there were no observable changes
with the bread however, there was a purple appearance with the milk and sausage.
5. Discuss in your own words the reasons for their findings.
State whether the following statements are TRUE/FALSE
6. Lactase is an enzyme.
7. Maltose breaks down proteins.
8. Enzymes are alive.
9. The pH and temperature can affect the functions of an enzyme.
10. Enzymes are substrate specific.
MINISTRY OF EDUCATION
SECONDARY ENGAGEMENT PROGRAMME
GRADE 9
INTEGRATED SCIENCE
Week 7
Topic: Enzymes
Worksheet - Answer
1. ENZYME- Enzymes are proteins that are produced by living organisms to aid in specific
biochemical reactions.
ACTIVE SITE- is the region of an enzyme where substrate molecules bind and undergo a
chemical reaction.
SUBSTRATE- the substance on which an enzyme act.
2. A- Active site
B- Enzyme
C- Substrate
3. In animals, an important function of enzymes is to help digest food.
Enzymes allow reactions to occur at the rate necessary for life.
4.
● Enzymes are highly specific for a particular substrate.
● Enzymes remain unchanged during the reaction itself.
● Enzymes are very efficient, catalyzing about 1-10,000 molecules of substrate per
second.
● Speeds up the rate of a reaction (activation energy) but does not change the equilibrium.
● Speeds up both forward and reverse reactions.
5. Enzymes are substrate-specific and do not breakdown all substances. Amylase breaks down
carbohydrates and not proteins.
6. TRUE
7. FALSE
8. FALSE
9. TRUE
10. TRUE