Marking Scheme Structure

8/9/2019 Marking Scheme Structure

1/9

SULIT 4551/2

Section A

[ 60 marks ]

Answerallquestions.

The time suggested to complete this section is 90 minutes.

1. Figure 1 shows two organelles X and Y , contained in a cell.

Figure 1

a) Identify organelle

X : mitochondrion

Y : chloroplast

[ 2

marks ]

b) State two similarities between organelles X and Y.

i) Both organelles can be found in a plant cell

ii)Both organelles have two layers of membranes

[ 2

marks ]

c) State one difference between the two organelles.

Organelle X can be found in both animal and plant cells while organelle Y

can only be found in the plant cell(or any other difference) [ 2marks ]

d) i) What is the main function of organelle X?

To generate energy in the form of ATP molecules

[ 1 mark ]

ii) How does organelle X function?

Through the oxidation of food during cell respiration.

[ 1 mark ]

4551/2 SULIT

2

UNTUK

KEGUNAAN

PEMERIKSA


2/9

SULIT 4551/2

e) i) State the name of the substance contained in organelle Y.

Chlorophyll

[ 1 mark ]

iii) What is the importance of organelle Y?

As a medium to absorb sunlight required for photosynthesis.

[ 1 mark ]

f) i) Write the name of the organelles P, Q, R and S in the boxes given in

Figure 2.

Figure 2

[ 2

marks ]

ii) State one type of cell that contained above organelles abundantly.

Pancreatic cells/ Cells in the salivary glands

[ 1 mark ]

2. Figure 3 shows three types of tissues found in the body of a multicellular

organism

Figure 3

a) Name the three types of tissues.

4551/2 SULIT

3

4 3 : 2 marks

2 : 1 mark

1 : 0 mark


3/9

SULIT 4551/2

A : Epithelial tissue

B : Nerve tissue

C : Muscle tissue

[ 3

marks ]

b) i) State the function of tissue A.

ITo cover and protect the whole external and internal surfaces of the body

and organs , also modified into glands for secretion of certain substances

[ 2

marks ]

ii) Name one organ which formed by tissue A and B.

Skin/ Brain/ etc.

[ 1 mark ]

c) i) Give one example of organ which is formed by tissue A and C.

Biceps/ etc.

[ 1 mark ]

ii) Name one system which the organ in (c) (i) involves in a multicellular

organism.

Muscular system (according to the above answer)

[ 1 mark ]

d) Describe briefly how the various organ system coordinate to regulate the blood

glucose level when it exceeds the normal level.

Glucose is absorbed from the small intestine of the digestive system.

The blood circulatory system transport the glucose to the liver .

When the blood glucose level exceeds the normal level, the pancreas will

secretes hormone insulin through the blood circulatory system to reduce the

exceeds level.

[ 3 marks ]

3. In an experiment, a similar cylinders of potatoes were separately immerse in

sucrose solutions of different concentration for two hours. The results are shown

in Table 1.

4551/2 SULIT

4


4/9

SULIT 4551/2

Table 1

a) Complete Table 1 [ 2

marks ]

b) From the data above, draw a graph of percentage of change of length of

potato cylinder against the concentration of sucrose solution.

[ 3

marks ]

c) From the graph drawn in (b), state the concentration of sucrose solutionwhich is isotonic to the potato cell sap.

4551/2 SULIT

5


5/9

SULIT 4551/2

0.28 M / any suitable value cutting x axis

[ 2

marks ]

d) i) Name the process which caused the change in length of potato cylinder

immerse in 0.4 M sucrose solution.

Plasmolysis

[ 1 mark ]

ii)Explain why the changes in (d) (i) happened.

The 0.4 M sucrose solution is hypertonic to the potato cell sap. This is

why water molecules move out of the cell by osmosis.

[ 2

marks ]

4. Proteins are complex organic molecules and they show four levels of

organisation. Figure 4 shows four different types of protein structures.

Figure 4

a) State the level of organisation for structures P, Q, R and S.

Protein Level of organisation

P Quaternary protein structureQ Secondary protein structure

R Tertiary protein structure

S Primary protein structure

[ 2

marks ]

b) Name three different of proteins found in the human body, each of the

proteins shows the level of organisation shown by P, Q or R. State one

function for each of the named protein.

4551/2 SULIT

6

4 3 : 2 marks

2 : 1 mark

1 : 0 mark


6/9

SULIT 4551/2

Protein Example Function

P Haemoglobin To transport oxygen

Q Keratin Found in hair, horn and nails

R Enzyme Biological catalyst that speeds up

biochemical reaction in the cells

[ 3

marks ]

Compliment E & F : 1 mark

c) i) State the differences between essential and non-essential amino acids.

Essential amino acids are amino acids that cannot be synthesised in

the body and must be included in the diet.

Non- essential amino acids can be synthesised from other amino acids

in the body

[ 2

marks ]

ii) Animal proteins are first class protein and plant protein are second class

proteins. Explain how a vegetarian can obtain all the essential amino

acids in his diet.

By eating a wide variety of vegetables, e.g. mixture of different legumes

and corn to obtain all the essential amino acids.

[ 2marks ]

d) Name a disease caused by lack of protein in the diet of human.

Kwashiorkor

[ 1 mark ]

e) Describe briefly a food test to show that egg albumen contains proteins.

Biuret test

4551/2 SULIT

7


7/9

SULIT 4551/2

2 ml of egg albumen is placed into a test tube and 2 ml 5% KOH

solution is added. The mixture is added with two drops of 1% copper

sulphate solution.

A purple colour is formed indicating the presence of protein in eggalbumen.

[ 3

marks ]

5. Figure 5 illustrates the action of an enzyme.

Figure 5

a) What are represented by W, X, P and Q?

W is enzyme, X is substrate while P and Q are products.

[ 2

marks ]

b) Name the structure in the cell where W is synthesised.

Ribosome

[ 1 mark ]

c) State two factors which can alter the shape or charges of R.

i) High temperatures

ii)Extreme pH

[ 2

marks ]

d) State a property of enzyme that is depicted in Figure 4.

Enzyme are highly specific.[ 1 mark ]

4551/2 SULIT

8


8/9

SULIT 4551/2

e) Based on Figure 4, explain why a small amount of enzyme can catalyse a

large amount of substrate?

This is because enzymes are not used up at the end of a reaction. Once the

products formed leave the active site of the enzyme, the enzyme is free to

participate in further reaction.

[ 2

marks ]

f) Draw a curve in the graph below to show how pH affects enzyme activity.

[ 1 mark ]

g) Figure 5 shows a handkerchief with grease stain and bloodstain (U). This

handkerchief was washed for 10 minutes with an enzyme-containing

washing powder at room temperature. The handkerchief after washing is

shown in (V).

Figure 5

i) Name two enzymes that can be found in this washing powder.

Protease and lipase

[ 2

marks ]

4551/2 SULIT

9


9/9

SULIT 4551/2

ii)A woman complained that the washing powder is not effective in

removing the stains when she washed her clothing at 60oC. What would

be the reason for this problem?

The enzymes are denatured at high temperature.

[ 2 marks ]

4551/2 SULIT

10

Documents

Marking Scheme Structure