OFFICIAL OCR A2 Biology - F214 Thread

You know you're going crazy when you read the words
-glucose
-glucagon
-glycogen
-glycogenesis
-glucogenolysis
-gluconeogenesis
and start laughing like a psycho o.O

I have a question on the calvin cycle.....

so, I understand that when we take away light from a plant the supply of ATP and NADP stops, as the light dependent stage cannot occur, this means that GP cannot be converted into TP anymore and so GP concentration builds up.

So, my book says that the calvin cycle continues untill all the TP is used up...... what I dont understand is how can the calvin cycle continue, converting TP to RuBP, when there is no ATP? Dont we require ATP to convert TP to RuBP?

I have a question on the calvin cycle.....

so, I understand that when we take away light from a plant the supply of ATP and NADP stops, as the light dependent stage cannot occur, this means that GP cannot be converted into TP anymore and so GP concentration builds up.

So, my book says that the calvin cycle continues untill all the TP is used up...... what I dont understand is how can the calvin cycle continue, converting TP to RuBP, when there is no ATP? Dont we require ATP to convert TP to RuBP?

Can someone please give me an exam-style outline of the Krebs cycle?
Eternal love and rep up for grabs

could anyone explain beta oxidation is a sentence ?!? please

Slacking..majorly. I need to get this U up to an A. ahhh FML.

Yes, the calvin cycle continues until all the TP has been used up - this means that TP is converted into other stuff like hexose sugars (glucose, fructose etc.) and glycerol - to make AA and sugars - until the TP has been used up fully . So it wouldn't be converted to RuBP because ATP is needed for that process, but will be converted to other stuff.

I found these these notes....there are amazing..it has evrything you need for biology
http://www.thestudentroom.co.uk/attachment.php?attachmentid=85673&d=1275233677

When refering to oxidisation and reduction reactions... is it okay to just explain how reduction is the gaining of a hydrogen atom, and oxidisation the loss. Or do we need to include details on electrons... because this does confuse me slightly.

Describe the main features of the Krebs cycle. No credit will be given for a flow diagram [7 Marks + 1 QWC Mark]

-The Krebs Cycle is a series of small steps
-Each catalysed by specific enzymes
-Citrate (6C) is the first compound formed by
-Oxaloacetate (4C), the acceptor molecule with the
-Addition of Acetate (2C) via acetyl CoA
-Citrate (6C) undergoes decarboxylation which
-Releases (2 molecules) of carbon dioxide and
-Undergoes dehydrogenation
-Releasing (4 pairs) of hydrogen to
-Hydrogen acceptors such as
-FAD and NAD
-Each cycle generates 3 reduced NAD and
-1 reduced FAD though
-There are 2 cycles/1 glucose molecule so one glucose molecule generates 6 reduced NAD and 2 reduced FAD
-Also ATP is formed by
-Substrate-level phosphorylation
-Reduced FAD and NAD are used in Oxidative Phosphorylation.

Each bullet point is a mark, so all 17 valid marking points are here.

Hope it helps.

PLEASE PLEASE PLEASE can someone give me the january paper we did for this module?????

Just remember it in terms of electrons: Oxidation Is Loss of electrons, Reductions Is Gain of electrons, OILRIG (: