Paper3~Qs 2

Its about enzyme!

There are many factors that affect the ability of an enzyme to catalyse biochemical reaction. Among the factors are pH, temperature, concentration of the substrate and concentration of enzyme. When the concentration of an enzyme increases, more enzyme molecules are available.

Based on the above information, plan a laboratory experiment to study the effect of salivary amylase concentration on the rate of biochemical reaction.

Terdapat banyak faktor yang mempengaruhi kebolehan enzim dalam memangkinkan sesuatu tindakbalas biokimia. Antara faktor-faktor tersebut ialah pH, suhu, kepekatan substrat dan kepekatan enzim. Apabila kepekatan enzim bertambah, maka terdapat lebih banyak molekul enzim.
Berdasarkan maklumat di atas, rancang satu eksperimen dalam makmal untuk mengkaji kesan kepekatan enzim amilase air liur terhadap kadar tindakbalas biokimia.

The planning of your experiment should include the following aspects:
Perancangan kerja eksperimen anda perlu meliputi aspek-aspek berikut:

Problem statement
Pernyataan masalah

Objective of investigation
Objektif kajian

Hypothesis
Hipotesis

Variables
Pembolehubah

List of apparatus and materials
Senarai alat radas dan bahan

Technique used
Teknik yang digunakan

Experimental procedure or method
Kaedah atau prosedur eksperimen

Presentation of data
Cara data dikomunikasikan

Conclusion
Kesimpulan [17 marks]

SUGGESTED ANSWER:

AIM: To study/ investigate the effect of salivary amylase / enzyme concentration on the rate of (biochemical) reaction

PROBLEM STATEMENT:

What is the effect of salivary amylase / enzyme concentration on the rate of (biochemical) reaction ?

HYPOTHESIS

The higher the salivary amylase / enzyme concentration, the higher the rate of (biochemical) reaction until it reaches a maximum rate

VARIABLES

Manipulated: Salivary amylase / enzyme concentration

Responding:Rate of (biochemical) reaction // time taken for breakdown of starch

Fixed: pH, substrate concentration, temperature

APPARATUS AND MATERIALS

Beakers, test tubes, syringe, dropper, glass rod, white tile, thermometer, stopwatch, water bath (wire gauze, bunsen burner, tripod stand), test tube rack, starch solution, iodine solution, salivary amylase/ saliva, distilled water

TECHNIQUE:

Measure and record the time taken for breakdown / hyrolysis of starch// iodine solution to change colour from blue black to brownish yellow using a stopwatch

PROCEDURE:

Able to list down the complete and correct procedure used based on the following criteria
K1 – Technique of assembling the apparatus to carry
out the experiment.
K2 – Technique of fixing the constant variables
K3 – Technique of changing the manipulated
variables
K4 – Technique of measuring the responding
variables
K5 - Technique of taking precautions to increase accuracy

Suggested Answer:

1. Label six test tubes as A, B, C, D, E and F. (K3)
2. Fill each test tube with solutions as shown in the table below. (K1, K3)

Test tube Volume of saliva (ml) Volume of distilled water (ml)

A 0.5 2.5

B 1.0 2.0

C 1.5 1.5

D 2.0 1.0

E 2.5 0.5

F 3.0 0.0

3. Drop a few drops of iodine separately on a white tile. (K1)
4. Pour 4 ml of starch solution into test tube A. (K2)
5. Start the stopwatch immediately. Use a dropper to withdraw a small amount of the mixture and add it to a drop of iodine on the white tile immediately. (K1, K5)
6.Observe the colour change in iodine. (K4)
7.Carry out the iodine test at an interval of 30 seconds until the blue-black colour no longer appears and the iodine solution remains brownish yellow. (K1, K2)

8. Record the time taken for the complete hydrolysis of starch. (K4)
9. If blue black colour is still produced after eight minutes, terminate the experiment with the reaction mixture. (K5)
10. Repeat steps 4 to 8 for test tubes B,C, D, E and F. (K1, K3)

11. Record all your observations. (K4)

12.Plot a graph of rate of reaction [1/time] against enzyme concentration. (K1)

RESULT:

CONCLUSION:

The higher the salivary amylase / enzyme concentration, the higher the rate of (biochemical) reaction until it reaches a maximum rate. Hypothesis is accepted