june 2005 wjec unit 1

Question 1

Diagram of a ribosome?

Answer 1

2 attachment sites on ribosome
1 on bottom half

Question 2

What 2 chemical components make up a ribosome?

Answer 2

ribosomal RNA
protein

Question 3

Where are ribosomes synthesised?

Answer 3

nucleolus

Question 4

Differences between triglycerides and phospholipids?

Answer 4

Triglyceride - 3 fatty acids
Only has glycerol head
around delicate organs such as kidney

phospholipid - 2 fatty acids
phosphate + glycerol head
cell membranes

Question 5

High intake of which of these fatty acids might be a contributory factor in heart disease?

Answer 5

stearic

Question 6

name given to technique where diagram below shows the results of a test which can be used to analyse evidence left at the scene of a crime?

Answer 6

DNA profiling

Question 7

2 types of evidence left at the scene of the crime which may have been used to provide DNA sample?

Answer 7

blood hair

Question 8

What does restriction endonuclease do?

Answer 8

cut the DNA into fragments

Question 9

What does gel electrophoresis do?

Answer 9

separates DNA fragments

Question 10

Other than criminal investigation where is this technique take place?

Answer 10

Paternity suit

Question 11

Explain the results as fully as you can?

Answer 11

(ii) Membrane (proteins) are stable between 10 and 40ºC
(Appearance of the red pigment means that) the (tonoplast and) cell membrane has been damaged between 40 and 50ºC
(meaning) pigment has leaked out of cells
permeability/damaged membrane;
proteins change shape/denature and come out of bilayer;
phospholipids bilayer has become too fluid
3

Question 12

Explain the difference in the results if you were investigating the effect of ethanol on the permeability of the membrane?

Answer 12

Dissolves phospholipids
So pigment leaks out.

Question 13

Suggest bead size which should be used in the process?

Answer 13

2 gives highest % of product

Question 14

2 reasons for the different results from the 3 bead sizes?

Answer 14

the smaller beads have a higher percentage of product
because it has a larger surface area therefore more is able to react

Question 15

What would you expect to happen to the results if the flow rate was decreased?

Answer 15

Percentage product would increase
More time for enzyme-substrate complexes to occur

Question 16

What other factor should be kept constant during the experiment

Answer 16

Temperature

Question 17

2 advantages of using immobilised enzymes in industrial processes?

Answer 17

more stable in a wider range of condition/temps/pH

Question 18

2 components of a virus?

Answer 18

protein coat
ring of plasmid

Question 19

Treatment used for cystic fibrosis?

Answer 19

Gene therapy

Question 20

describe another delivery system which could be used to introduce the gene to the lung cells

Answer 20

(c) Use of liposomes;

Transfer of non CF gene (into plasmid);

Coated in (spheres of) phospholipids/lipid (bilayer);

Breathed into lung via aerosol/inhaler.

Question 21

which events must occur once the replacement is inside the lung cell for the transparent to be successful?

Answer 21

Gets into nucleus; Insertion into chromosome;
Transcription
Translation

Question 22

1 hazard of introducing a gene into the lung tissue to correct cytosis fibrosis?

Answer 22

Activation of oncogenes;
Unexpected disease caused/leukaemia;