Unit 1 Biology
- Created by: shriya
- Created on: 20-05-13 19:40
Describe the 3 dimensional structure of a Enzyme protein
· Globular
· State they have an active site
· Reference to named bonds and interactions between the R groups
· Hydrophobic interactions between R groups di-sulphide bridges hydrogen bonds and ionic bonds alongside with Vander Waals forces. (Total 3 marks)
How does the primary structure determine the final structure?
· Position/ sequence/order of the amino acids
· This determines the types of bonds and folding that will take place
· It determines the shape and properties of the active site
· Causes enzyme substrate complex to be formed
· The enzyme is then hydrophilic on the outside and hydrophobic on the inside
· Hence it also creates solubility in water
HOW DOES GAS EXCHANGE OCCUR IN AMOEBA
· It occurs through the cell membrane
· The membrane is quite thin
· Oxygen enters from water
· Carbon dioxide leaves cell into water
· O2 and CO2 are both non polar molecules and so diffuse in
· Down a concentrate gradient
· And an amoeba has a large surface area to volume ratio
If two beetroot experiments were being carried out what factors have to be kept constant for both experiments?
· The pre-treatment methods should be the same
· The size of the beetroot cut should be the same
· Beetroot storage conditions should be the same
· Incubation time should be the same
· Volume concentration
· PH water
Comment on how the results could be more reliable ?
· If not before then in the second experiment use a colorimeter as it is more precise
· The experiment was repeated
Describe the structure of glycogen and explain why it insoluble?
· Glycogen consist of Alpha glucose
· That are joined together by (1-4) and (1-6) glycosidic bonds
· Branched structure
· And it has a compact structure
· It hydrolysed rapidly
· Leading to more glucose in less space
· So it has low solubility
· Does not diffuse outside the cell
· And hence has no osmotic effect
(This answer in the exam got all 3 marks)
The ethical and social issues with parental testing
· If the disease is identified the child still has a right to live and abortion is murder if a miscarriage takes place
· False positive/negative and the consequences behind it for example if the results for a genetic order prove positive and yet are wrong then a perfectly healthy foetus could be aborted
· Who has the right to decide whether the tests should be performed or not? It can cost quite a lot there may not be agreement…
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