OCR AS Biology (F211) - May 2014

Yeah, I don't mind.
Basically, companion cells release H + ions from their cytoplasm into surrounding tissue, this decreases the concentration of H + ions in the companion cells, resulting in the creation of a H + ion concentration gradient. Then due to diffusion the hydrogen ions come back into the cytoplasm if the companion cells, however pass through co transporter proteins which enable them to bring sucrose back into the companion cells.
Hope it helps. :smile:

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Where do the protons come from?

Reply 61

cjslions

2

Has anyone done the enzyme ISA??

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Reply 62

mrmattaiusify

4

Hi

Could someone tell me about protein synthesis? Transcription and translation and that.

I have three books and all three do not cover it for whatever reason. Or it isn't in enough detail.

Thanks :smile:

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Reply 63

smozsolution

9

Original post by mrmattaiusify

Hi

Could someone tell me about protein synthesis? Transcription and translation and that.

I have three books and all three do not cover it for whatever reason. Or it isn't in enough detail.

Thanks :smile:

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Funny you should ask that, I was looking at the specification earlier for protein synthesis myself!

I don't believe we need to know it in detail because the spec says this:

outline the interrelationship between the organelles involved in the production and secretion of proteins (no detail of protein synthesis is required)

Reply 64

thespontaneous1

Original post by mrmattaiusify

Hi

Could someone tell me about protein synthesis? Transcription and translation and that.

I have three books and all three do not cover it for whatever reason. Or it isn't in enough detail.

Thanks :smile:

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Not in spec at all. Pretty sure you only need to outline role of mRNA briefly and mostly put emphasis on role of golgi, ribosomes, RER, vesicles and process of excocytosis working in tendum to produce extracellular proteins. In case of intracellular proteins the ribosomes are free flowing in cytoplasm rather than being attatched to RER.

Always use spec as checklist to see what you need to know for F211 for any ocr bio exam.

Reply 65

games211

16

i have lost all hope :frown:

how is everyone revising for it? Just making a4 page notes?

Reply 66

finnthehuman

11

Original post by thespontaneous1

Not in spec at all. Pretty sure you only need to outline role of mRNA briefly and mostly put emphasis on role of golgi, ribosomes, RER, vesicles and process of excocytosis working in tendum to produce extracellular proteins. In case of intracellular proteins the ribosomes are free flowing in cytoplasm rather than being attatched to RER.

Always use spec as checklist to see what you need to know for F211 for any ocr bio exam.

Original post by mrmattaiusify

Hi

Could someone tell me about protein synthesis? Transcription and translation and that.

I have three books and all three do not cover it for whatever reason. Or it isn't in enough detail.

Thanks :smile:

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This is in F212 :smile:

.

I will try and get back to you within a week, just currently sorting out my life, so sorry for the wait.

Reply 67

mrmattaiusify

4

Original post by smozsolution

Funny you should ask that, I was looking at the specification earlier for protein synthesis myself!

I don't believe we need to know it in detail because the spec says this:

The thing is though, it has come up in past papers in quite some detail. One question was the old fill in the gaps thing and one of the answers was "anti codon" and another was "translation".

Both of these terms (as far as I know) aren't mentioned in the OCR book :/

I've just resorted to making notes from past papers and mark schemes on it for now. Hopefully it shouldn't come up though. You are right, it does say "in outline only" on the specification.

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Reply 68

Saywhatyoumean

10

Hey I'm sitting this too, quick question

Why can residual air not be exhaled?

I get that it's because the thorax can't completely be flattened but what does the trachea and bronchioles being held open have to do with anything?

Thanks

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Reply 69

a123a

14

Original post by Saywhatyoumean

Hey I'm sitting this too, quick question

Why can residual air not be exhaled?

I get that it's because the thorax can't completely be flattened but what does the trachea and bronchioles being held open have to do with anything?

Thanks

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I think it's because you also can't completely compress the trachea and bronchioles as they are held open by the elastic fibres. I would think that if you could exhale the residual air your whole system would collapse due to low pressure.
Not sure though...

Reply 70

biologist22

We did the June 2013 paper for our mock exam. This paper seemed harder and different to all the other past papers as there was quite a lot of application and thinking in there.

What do you guys think?

Reply 71

thespontaneous1

Original post by biologist22

We did the June 2013 paper for our mock exam. This paper seemed harder and different to all the other past papers as there was quite a lot of application and thinking in there.

What do you guys think?

I agree the lenticles question had many people stumped, in addition to that the hydrogen peroxide question did too. Personally it was harder than usual which justified the 43 out of 60 boundary for an A. The mark scheme was very very iffy lots of contradictions, something my teacher noted too.

Im just hoping our exam this May doesnt have an abyssmal 6-7 marker on electrical transmissions in the heart or diastole etc etc question. Man i hate the heart/animal transport and plant transport.

Reply 72

smozsolution

9

Original post by mrmattaiusify

The thing is though, it has come up in past papers in quite some detail. One question was the old fill in the gaps thing and one of the answers was "anti codon" and another was "translation".

Both of these terms (as far as I know) aren't mentioned in the OCR book :/

I've just resorted to making notes from past papers and mark schemes on it for now. Hopefully it shouldn't come up though. You are right, it does say "in outline only" on the specification.

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Was it a unit 1 or 2 paper? Or was it an older past paper? I don't know if that helps though because I didn't know we had to know those things and like you said, they aren't mentioned in the OCR book.

Like you said, we can only hope it doesn't come up though. I'll recheck the specification in case we've missed something.

Reply 73

Saywhatyoumean

10

Hi guys I just have a question about oxygen dissociation.

So does adult haemoglobin have the same affinity to oxygen everywhere in the body including lungs and tissues?

So at high altitudes, the overall affinity to oxygen of haemoglobin reduces to ensure that respiring tissues gain the oxygen they need

The oxygen tensions change but the affinity doesn't?

Is that right?

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Reply 74

bbadonde2

4

Original post by Saywhatyoumean

Hi guys I just have a question about oxygen dissociation.

So does adult haemoglobin have the same affinity to oxygen everywhere in the body including lungs and tissues?

So at high altitudes, the overall affinity to oxygen of haemoglobin reduces to ensure that respiring tissues gain the oxygen they need

The oxygen tensions change but the affinity doesn't?

Is that right?

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Yes the affinity for the Iron groups within the ADULT Haemoglobin molecule does not change as you go down the body. Also, the overall affinity does decrease but the number of erythrocytes increases this means the blood has more oxygen carrying capacity. The oxygen tension can increase or decrease and this will have no direct effect on the affinity of the Fe group, however, if the erythrocyte is saturated with three oxygen molecules the 'conformational change' in shape of the red blood cell means it's hard for the fourth oxygen to associate.

Reply 75

Marmite97

1

Original post by mrmattaiusify

The thing is though, it has come up in past papers in quite some detail. One question was the old fill in the gaps thing and one of the answers was "anti codon" and another was "translation".

Both of these terms (as far as I know) aren't mentioned in the OCR book :/

I've just resorted to making notes from past papers and mark schemes on it for now. Hopefully it shouldn't come up though. You are right, it does say "in outline only" on the specification.

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I remember my teacher saying that some of the stuff is not in our spec in as much detail as before so it's worth double checking before learning it all 😅

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Reply 76

Alltimesarah

2

So what do you think the questions will be on?
I personally think there'll be a lot of calculations and enzymes

Reply 77

GXO

2

Original post by Jemzbee

Anyone done the enzymes isa yet? For f212

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I've got mine tomorrow and fully dreading it! biology ISAs are so much harder than chemistry! Literally all my class is not at a good mark for the last two ISAs

Reply 78

ChelsieJayne

[QUOTE="Shadow_Amber;46267966"]

Original post by Jemzbee

Anyone done the enzymes isa yet? For f212

I had the enzyme quantitative today.

It was the effect calcium concentration has on coagulating of milk proteins

Post rating: 0

Hi I have this in a week any advise regarding what to revise? Any help would be appreciated :smile:

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Reply 79

ChelsieJayne

Original post by GXO

I've got mine tomorrow and fully dreading it! biology ISAs are so much harder than chemistry! Literally all my class is not at a good mark for the last two ISAs

Hi I have this soon :frown:

Do you have any advise regarding what to revise? Any help would be appreciated :smile:

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OCR AS Biology (F211) - May 2014

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