Properties of Enzymes

Author:Mary Jones & Geoff Jones
Upper Secondary: IGCSE
IMPORTANT

Important Questions on Properties of Enzymes

HARD
IMPORTANT

Students investigated a sample of amylase from 100 Goats. 100 Small filter paper discs were each soaked in a different sample of goat amylase. The students tested the activity of these amylase samples using plain paper. The plain paper contains starch. A circle of plain paper was placed into a petri dish as shown in the diagram below. Iodine solution was used to stain the starch on plain paper.
Ten amylase-soaked filter paper discs were placed into one of the Petri-dishes as shown in the diagram. The students lifted the filter paper discs at one-minute intervals and recorded the number of areas where there had been a reaction.

Question Image

If a reaction had not taken place, the students replaced the disc of filter paper for another minute. This procedure was repeated for five minutes. Their results are recorded in the table below.

Question Image

Suggest three ways in which you could improve this investigation.

HARD
IMPORTANT

Students investigated a sample of amylase from 100 Goats. 100 Small filter paper discs were soaked in a different sample of goat amylase. The students tested the activity of these amylase samples using plain paper. The plain paper contains starch. A circle of plain paper was placed into a petri dish as shown in the diagram below. Iodine solution was used to stain the starch on plain paper.
Ten amylase-soaked filter paper discs were placed into one of the Petri-dishes as shown in the diagram. The students lifted the filter paper discs at one-minute intervals and recorded the number of areas where there had been a reaction.

Question Image

If a reaction had not taken place, the students replaced the disc of filter paper for another minute. This procedure was repeated for five minutes. Their results are recorded in the table below.

Question Image

Suggest two reasons for the differences in amylase activity of the samples.

HARD
IMPORTANT

Students investigated a sample of amylase from 100 Goats. 100 Small filter paper discs were each soaked in a different sample of goat amylase. The students tested the activity of these amylase samples using plain paper. The plain paper contains starch. A circle of plain paper was placed into a petri dish as shown in the diagram below. Iodine solution was used to stain the starch on plain paper.
Ten amylase-soaked filter paper discs were placed into one of the Petri-dishes as shown in the diagram. The students lifted the filter paper discs at one-minute intervals and recorded the number of areas where there had been a reaction.

Question Image

If a reaction had not taken place, the students replaced the disc of filter paper for another minute. This procedure was repeated for five minutes. Their results are recorded in the table below.

Question Image

Plot a graph using the data from the first two columns, to show the differences in the activity of amylase.

HARD
IMPORTANT

Students investigated a sample of amylase from 100 Goats. 100 Small filter paper discs were each soaked in a different sample of goat amylase. The students tested the activity of these amylase samples using plain paper. The plain paper contains starch. A circle of plain paper was placed into a petri dish as shown in the diagram below. Iodine solution was used to stain the starch on plain paper.
Ten amylase-soaked filter paper discs were placed into one of the Petri-dishes as shown in the diagram. The students lifted the filter paper discs at one-minute intervals and recorded the number of areas where there had been a reaction.

Question Image

If a reaction had not taken place, the students replaced the disc of filter paper for another minute. This procedure was repeated for five minutes. Their results are recorded in the table below.

Question Image

Copy and complete the table by calculating the total number of areas where there had been a reaction after 4 and 5 minutes.

HARD
IMPORTANT

Three enzymes P, Q, R were extracted from a different region of the alimentary canal of a mammal. The effect of PH On the activity of the enzymes was investigated at 40°C. The results are shown in the diagram below. Using the information in the diagram, describes the effect of increasing PH On the rate of activity of enzyme Q?

Question Image

HARD
IMPORTANT

Three enzymes P, Q, R were extracted from a different region of the alimentary canal of a mammal. The effect Of PH On the activity of the enzymes was investigated at 40°C. The results are shown in the diagram below. 

Question Image

Explain Why the investigation was carried out at 40°C.?

HARD
IMPORTANT

Explain why the rate of reaction slows down above the enzyme’s optimum temperature?

HARD
IMPORTANT

Explain why the rate of enzyme-controlled reaction is relatively slow at low temperatures.

HARD
IMPORTANT

A protease enzyme is found in the stomachs of humans. The stomach contains Hydrochloric acids. Suggest the optimum PH For the activity of this protease enzyme.

HARD
IMPORTANT

A protease enzyme is found in the stomachs of humans. It catalyzes the breakdown of long chains of amino acids (proteins) into individual amino acid molecules. Suggest the optimum temperature for the activity of these protease enzymes.

MEDIUM
IMPORTANT

Explain the meaning of this term: Denatured

MEDIUM
IMPORTANT

Why are the enzymes damage by high temperature?

HARD
IMPORTANT

What is the optimum temperature for the enzyme in given figure?

Question Image

MEDIUM
IMPORTANT

What is meant by an optimum temperature?