OFFICIAL OCR A2 Biology - F214 Thread

Is anyone here also sitting f215 this session ? :tongue:

EDIT:Oh yea I will never forget the "seal question" lol

Your paper.. January 2010 was HARD! Well i think anyway.. all that stuff on kidney, SEALS!.. June paper was much better.. wonder how our paper will be! Ah so scared! Biology can proper trip you up with the random questions!

Reply 3981

Waqar Y

11

https://sites.google.com/a/kings-wton.co.uk/science/Home/a-level-biology

here, found a site which has it - i had it anyway but i cba emailing to anyone anymore LOL

Reply 3982

ibysaiyan

16

Original post by Waqar Y

https://sites.google.com/a/kings-wton.co.uk/science/Home/a-level-biology

here, found a site which has it - i had it anyway but i cba emailing to anyone anymore LOL

Awesome it has f215 too! Thanks!

Reply 3983

slacker07906

16

Not feeling good about this exam but...im going to do my best, and that's all I can do. I'm not very good at biology. Can anyone help?

What are the functions of the loop of henle, and describe how length effects the water potential?

Reply 3984

Waqar Y

11

Original post by slacker07906

Not feeling good about this exam but...im going to do my best, and that's all I can do. I'm not very good at biology. Can anyone help?

What are the functions of the loop of henle, and describe how length effects the water potential?

Function of the loop of henle is to reabsorb water, this is done by the hair-pain counter current multiplier.
This is because each of the tubules are arranged like a hairpin, consisting of the ascending limb and descending limb,
Will start with the ascending limb because that's easiesr then, basically the ascending limb is impermeable to water, it has interstatial tissue and is able to pump NA/CL+ into the surrounding medulla tissue, this lowers the water potential in the medulla tissue.
When the tubule fluid is passing through, there's a higher water potential in the tubule fluid then outside, so water moves out by osmosis and NA/CL moves in by diffusion, since there's a higher conc of solutes outside then inside.
Just before the ascending limb, NA/CL ions are able to diffuse out before they go up through the interstatial tissue; you end up with a higher water potential as NL/CL ions are actively transported out(see above)

When the tubule fluid reaches the collecting duct, water can move out by osmosis because NA/CL has been actively transported out.
The bigger the loop of henle, the more ions that have been actively transported out, so the lower the water potential; which means more water will go out from the collecting ducts through osmosis.

Reply 3985

aimz08

OP

13

Original post by ibysaiyan

Is anyone here also sitting f215 this session ? :tongue:

EDIT:Oh yea I will never forget the "seal question" lol

Me...

Struggling with genetic diagrams :frown:

how are you finding it all?

Reply 3986

ibysaiyan

16

Original post by aimz08

Me...

Struggling with genetic diagrams :frown:

how are you finding it all?

I am fine with the whole genetics now.I haven't revised f215 for 5 days.. I will try to finish variation stuff today.Oh by the way if you got any problems,topic to discuss there is a thread specifically for f215. :tongue:

Thank God I am not doing f214 anymore =]

(edited 13 years ago)

Reply 3987

Deyn_08

11

Original post by ibysaiyan

Is anyone here also sitting f215 this session ? :tongue:

EDIT:Oh yea I will never forget the "seal question" lol

terrible

you have to really think outside the box for that one.

Reply 3988

nazirard

Original post by ibysaiyan

Is anyone here also sitting f215 this session ? :tongue:

EDIT:Oh yea I will never forget the "seal question" lol

Not doing F215 but that question was bloody hard. And the mark scheme was really lenient. There were like 10 points for 3 marks. I got all 3 marks though :smug:

Reply 3989

username340050

Im fine with Photosynthesis because I made a reallllly cheesy (But interesting) story that links it all up.

But with ~~photosynthesis~~ RESPIRATION, that NADH can produce approximately 2.6x ATP and the net gain of ATP overall is 30 (But usually not achieved) feels like a fact that I shouldn't forget. Blame the Instinct...

(edited 13 years ago)

Reply 3990

nazirard

Original post by Faisal-Fm

Im fine with Photosynthesis because I made a reallllly cheesy (But interesting) story that links it all up.

But with photosynthesis, that NADH can produce approximately 2.6x ATP and the net gain of ATP overall is 30 (But usually not achieved) feels like a fact that I shouldn't forget. Blame the Instinct...

Photosynthesis? Do you mean respiration? :confused:

Reply 3991

username340050

Original post by nazirard

Photosynthesis? Do you mean respiration? :confused:

Pardon my mistake.

Its one of those confusions you get when you think about one think, and write the other... ¬_¬"

But seriously, Id say Krebs/OxiPhos/Glycolysis will show up. And so will neurones ¬_¬"

Reply 3992

slacker07906

16

Do we have to learn about the photosynthometer?

Reply 3993

nazirard

Original post by Faisal-Fm

Pardon my mistake.

Its one of those confusions you get when you think about one think, and write the other... ¬_¬"

But seriously, Id say Krebs/OxiPhos/Glycolysis will show up. And so will neurones ¬_¬"

A bit of each module is bound to turn up.
I hate homeostasis. Haven't done it in ages! :angry:

Original post by slacker07906

Do we have to learn about the photosynthometer?

I'd say that's pretty important because it's about the rate of photosynthesis. It was in a recent paper so my advice is yes. :biggrin:

Bu it's not that long to learn I guess.
Good luck.

Reply 3994

Mally-xo

14

if anyone wants me to email them the notes I have made for this unit, private message me your email address :tongue:

I haven't done my respiration topic yet, so they are missing at the moment, but they should be finished entirely by the end of the week.

one thing I reallllyyy don't understand is the whole thylakoid/lamellae/grana thing. are they all the same thing or something? :confused:

(edited 13 years ago)

Reply 3995

nazirard

Original post by Mally-xo

if anyone wants me to email them the notes I have made for this unit, private message me your email address :tongue:

I haven't done my respiration topic yet, so they are missing at the moment, but they should be finished entirely by the end of the week.

one thing I reallllyyy don't understand is the whole thylakoid/lamellae/grana thing. are they all the same thing or something? :confused:

The Lamellae is the same things as the thylakoid but is distinguished as you need to know where each photosystem is located. Photosystem 1 (700) is found in the intergranal lamallae and photosystem 2 (680) is found n the granal lamellae if I remember correctly (can't be asked to check my book but you should check it)

Lamellae=Thylakoid=folded stacks of flattened mambrane or what not.
Grana = The stacks of thylakoids.
Granal and intergranal lamellae = where PS2 and PS1 are located respectively.
:smile:

Reply 3996

Mally-xo

14

Original post by nazirard

thanks very much, makes a bit more sense now haha :biggrin:

Reply 3997

Ro27

Hello all

I can't remember all the wavelengths absorbed by the different pigments for the life of me...
Anyone got an easy wayyy?

And are P680 & P700 both types of Chlorophyll a, because I read somewhere that one is a and the other is b and now I'm soo confused!

Thanksssss

Reply 3998

nazirard

Original post by Ro27

Hello all

I can't remember all the wavelengths absorbed by the different pigments for the life of me...
Anyone got an easy wayyy?

And are P680 & P700 both types of Chlorophyll a, because I read somewhere that one is a and the other is b and now I'm soo confused!

Thanksssss

P700 is photosystem 1 and p680 is photosystem 2. They both absorb red light and reflect yellow green light. This'll sound stupid but 1 looks like 7 so PS1 has a peak absorption of 700. :redface:

Maybe that's one way to remember it. :s-smilie:

I think all you need to know about Chlorophyll b is that it absorbs wavelengths of 500nm and 640nm (not everything in between). And it appears blue green.

Accessory pigments vary but carotenoids absorb blue light and reflect orange light. They pass the energy on to the primary pigment reaction centre that hasn't been absorbed.

These are the main ones you need to know I think.

Reply 3999

Ro27

Original post by nazirard

P700 is photosystem 1 and p680 is photosystem 2. They both absorb red light and reflect yellow green light. This'll sound stupid but 1 looks like 7 so PS1 has a peak absorption of 700. :redface:

Maybe that's one way to remember it. :s-smilie:

I think all you need to know about Chlorophyll b is that it absorbs wavelengths of 500nm and 640nm (not everything in between). And it appears blue green.

Accessory pigments vary but carotenoids absorb blue light and reflect orange light. They pass the energy on to the primary pigment reaction centre that hasn't been absorbed.

These are the main ones you need to know I think.

You're on fire with photosynthesis aren't you haha!
Positive rep coming your wayyyyyy about the lamallae thing that confused me big time :biggrin:

Erm, here's a Kidney Q!!!
What do the podocytes actually do in ultrafiltration? Seeing as it's the basement membrane that actually filters the blood?

I sound so damn thick right now how the hell did I get an A last year LOL

OFFICIAL OCR A2 Biology - F214 Thread

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you