AS Biology Questions

They're quite a few, but please bare with me.

1. Describe the structure of ribosomes and lyosomes.

2. Explain what is meant by enzyme immobolization.

3. What purpose do the elastic fibres in the aorta serve?

4. Compare the absorption of glucose to the absorption of glucose and fructose. Explain this difference.

5. How many chromosomes are present in the embroy?

6. Describe the role of myoglobin. [3 marks!]

7. Describe the importance of potassium hydroxide to germenating seeds.

8. Give two substances that are present in a higher concentration in the umbilical artery than in the maternal blood.

9. Suggest how the placenta enhances the exchange of substances with the maternal blood.

10. Describe the adaptions an organism that lives in still water could have.

11. Same as above, but in moving water.

And finally, sometimes they ask you questions in relation to radioactively labeled amino acids and stuff. What are general things I have to know about this? I can't see anything about them in the syllabus, and my text book is crappy. I hate my text book.

Thanks to anyone who can help.

Reply 1

shift3

OP

Anyone?

Reply 2

rocksteady99

1. Describe the structure of ribosomes and lyosomes.
Ribosomes-small black spheres
Lysosomes-small clear spheres

2. Explain what is meant by enzyme immobolization.
An enzyme that is not mobile. Either trapped onto alginate beads, an insoluble matrix, or cellulose fibres

3. What purpose do the elastic fibres in the aorta serve?
The have elastic recoil, which copes with blood at a high pressure and evens out the flow of blood
4. Compare the absorption of glucose to the absorption of glucose and fructose. Explain this difference.
?
5. How many chromosomes are present in the embroy?
23 pairs in each cell

6. Describe the role of myoglobin. [3 marks!]
oxygen transfer in muscles. lies to left of normal haemoglobin. so at lower partial pressures, it readily associates with oxygen, and only dissociates at very low partial pressures, in this way large quantities of o2 can be transported
7. Describe the importance of potassium hydroxide to germenating seeds.
?
8. Give two substances that are present in a higher concentration in the umbilical artery than in the maternal blood.
?
9. Suggest how the placenta enhances the exchange of substances with the maternal blood.
?

Reply 3

shift3

OP

Thank you! Although I don't know about the first answer, cause it was worth 3 marks if I recall correctly. My answer was "spherical shape with openings and sites that can bind to RNA."

Reply 4

shift3

OP

Bump.

Reply 5

Helenia

20

shift3

Thank you! Although I don't know about the first answer, cause it was worth 3 marks if I recall correctly. My answer was "spherical shape with openings and sites that can bind to RNA."

Ribosomes have two subunits, both containing ribosomal RNA and protein.

Reply 6

FidoDiDo

yea .. Ribosomes made up of 2 Subuints.. One larger than the other..
Lysozome = Spherical organelle .. surrounded by single boundry of membrane

Reply 7

Unregistered

rocksteady99

1. 6. Describe the role of myoglobin. [3 marks!]
oxygen transfer in muscles. lies to left of normal haemoglobin. so at lower partial pressures, it readily associates with oxygen, and only dissociates at very low partial pressures, in this way large quantities of o2 can be transported

just to make this clear, its oxygen dissociation curve lies to the left of
that of normal haemoglobin..

also, I don't really know what you mean about how this helps "large quantities of O2" to be transported. I think its significance is more that it acts as a "store" of oxygen in the muscles and will only give up its oxygen in conditions of very low oxygen (as you said) - i.e. when you are exercising and the muscle cells are respiring very actively.

may be worth throwing in oxygen debt - one of the reasons for the oxygen debt following exercise is that you need to reoxygenate the myoglobin.

rosie

Reply 8

ngkl

1. Ribosomes - consists of smaller and larger subunits and made up of RRNA and protein

Lysosoms - Lysosomes are a sinhle spherical sac bounded by a single membrane and contains hydrolytic/digestive enzymes

2. The process in which enzymes are attached/bound to an insoluble matrix to keep in position so that it would be more stable towards temperature and ph. Eg: sodium alginate beads

3. To allow the restretching and recoiling of the arteries as well as to withstand and reduce pressure in the arteries

4.Actually this is a past year question, the real question is compare galactose and fructose with glucose. Answer given: Fructose is not absorbed by active transport and/or the diffusion gradient or glucose galactose greater than fructose

5. 46, 23pairs

6. Act as an emergency stores of oxygen by delaying the onset of anaerobic respiration

7. ??

8. carbon dioxide and urea

9. presence of the chorionic villi that further increases surface area, large network, thin increase rate of diffusion, and the presence of a large number of capillaries

10. erm.... the waving of the posterior body e.g: tubifex worm to circulate the air surrounding the worm. Breathing siphons like in a rat-tailed maggot. The tube penetrates the surface of water to acquire oxygen and prevents water-logging

11. erm.. the body of the organism must be small to provide less resistance to water flow. Similar case for the dissected lamina of a hydrophyte plant. It's surface area is reduced to provide less resistance to water flow

hope i could help :smile:

FOr the labelled amino acids and stuff, you have to know the correct sequence of the protein cycle : ( how it's produced, modified and excreted ) and use that knowledge and apply it in your answer. You also have to know where the undetected amino acids went. hope i helped

Reply 9

shift3

OP

Thanks guys. I've got the exams in an hour... wish me luck! :biggrin:

Reply 10

dazzyaa911

shift3

Thanks guys. I've got the exams in an hour... wish me luck! :biggrin:

in an hour? at 6:30 in the morning?

Reply 11

Hash

Probably an international student

Reply 12

MalaysianDude

4

ngkl

1. Ribosomes - consists of smaller and larger subunits and made up of RRNA and protein

Lysosoms - Lysosomes are a sinhle spherical sac bounded by a single membrane and contains hydrolytic/digestive enzymes

2. The process in which enzymes are attached/bound to an insoluble matrix to keep in position so that it would be more stable towards temperature and ph. Eg: sodium alginate beads

3. To allow the restretching and recoiling of the arteries as well as to withstand and reduce pressure in the arteries

4.Actually this is a past year question, the real question is compare galactose and fructose with glucose. Answer given: Fructose is not absorbed by active transport and/or the diffusion gradient or glucose galactose greater than fructose

5. 46, 23pairs

6. Act as an emergency stores of oxygen by delaying the onset of anaerobic respiration

7. ??

8. carbon dioxide and urea

9. presence of the chorionic villi that further increases surface area, large network, thin increase rate of diffusion, and the presence of a large number of capillaries

10. erm.... the waving of the posterior body e.g: tubifex worm to circulate the air surrounding the worm. Breathing siphons like in a rat-tailed maggot. The tube penetrates the surface of water to acquire oxygen and prevents water-logging

11. erm.. the body of the organism must be small to provide less resistance to water flow. Similar case for the dissected lamina of a hydrophyte plant. It's surface area is reduced to provide less resistance to water flow

hope i could help :smile:

FOr the labelled amino acids and stuff, you have to know the correct sequence of the protein cycle : ( how it's produced, modified and excreted ) and use that knowledge and apply it in your answer. You also have to know where the undetected amino acids went. hope i helped

for q11...
it should have a larger surface area to trap the oxygen plowing through..
it should also have respiratory pigments for efficient oxygen absoprtion
has hairs to trap the oxygen bubbles

it does not neccesarily have to be a small animal

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