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OCR Biology F214 Communication, Homeostasis and Energy Wed 25 Jan 2012

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Original post by Bubbles94
Good night sleep. forget that type of revision. Odds are if you don't know it now, you wont have time to process the information and keep it in the long term memory for tomorrow..
Plus its a 9.15 exam, so you need to be awake for it.

9:00am isn't it?
Original post by TourettesUnicorn
What do you think is better, revising late into the night or a good night's sleep?


Good night's sleep defo :smile:
Original post by Bubbles94
Good night sleep. forget that type of revision. Odds are if you don't know it now, you wont have time to process the information and keep it in the long term memory for tomorrow..
Plus its a 9.15 exam, so you need to be awake for it.


it starts at 9 and is a 1hr 15min exam
Original post by The Illuminati
9:00am isn't it?


9.15 for my exam at my school
Original post by VQG
Can anyone confirm my knowledge of respiratory acidosis?
Is it the high concentration of CO2 in the blood lowering the pH of the blood (CO2+H20 --> H2CO3 <==> H+ HCO3-)
Detected by chemoreceptors in the cardiovascular center of the brain in the Medulla Oblongata. Medulla oblongata sends an action potential down to the heart via the accelerator (sympathetic) nerve which raises the heart rate, to try eliminate the CO2. Can result in even more CO2 accumulating hence more carbonic acid, which stops the heart functioning (heart attack).


i dont think the chemoreceptors are in the medulla oblongata, think they're in the carotid arteries
Original post by TourettesUnicorn
What do you think is better, revising late into the night or a good night's sleep?


For me its revising late into the night as I normally wake up pumped for an exam whether I stayed up till ten or till 3:00 AM.

Also you do remember a lot of stuff from the night before, no matter what the anti-crammers say. :wink:
Original post by The Illuminati
page 93. It was just to show where the different parts of respiration happened as if they removed a certain part, one process would stop.


Original post by Bubbles94
i can type out the whole experiment if you want :L


I think I have it:

Electron micrographs could see the stalked heads of ATP synthase in the mitochondiral inner membrane.

A steep electrochemical gradient is needed to produce ATP

When the outer membrane was removed no ATP was produces, so the intermembranal space is needed to produce ATP.

If the heads of ATP synthase were removed then no ATP was produced.

The antibiotic oligomysin blocks the protien channels and again no ATP was produed.

Chemiclas that increase the permeability of the membrane to H+ ions stop/reduce ATP production because the proton motive force is stopped.

right? :colondollar:
Reply 1027
Original post by Claudine
evidence for chemiosmosis anyone?!


Cyanide - blocks 3rd electron carrier in electron transport chain, thus stopping 1st and 2nd carriers from being oxidised again. This means electrochemical gradient can't build up and hey presto no ATP is produced when this is tested on isolated thylakoids.

Dinitrophenol - acts as a hydrogen/proton carrier when introduced to isolated thylakoids it carriers protons back across the membrane meaning no electrochemical gradient can build up, and you guessed it no ATP is produced.

Or....

Isolate thylakoids, place them in a ph4 buffer, so electrochemical gradient is lost.

Place in new ph4 buffer with ADP+Pi and no ATP is made.

Place in new ph8 buffer with ADP+Pi and the electrochemical gradient is restored and ATP is made.

Teehee :smile:
Original post by Chris P Chicken.
For me its revising late into the night as I normally wake up pumped for an exam whether I stayed up till ten or till 3:00 AM.

Also you do remember a lot of stuff from the night before, no matter what the anti-crammers say. :wink:


no i agree with cramming :L hell i do it,but till 3 am is just stupid :L
Original post by Bubbles94
9.15 for my exam at my school


It shouldn't be as all exams have to take place at the same time.

Unless your school isn't in the U.K?
Reply 1030
Original post by christrev
i dont think the chemoreceptors are in the medulla oblongata, think they're in the carotid arteries


They are in the medulla.... not sure about oblongata.

Carotid arteries is correct as well :smile:
Reply 1031
Original post by Chris P Chicken.
It shouldn't be as all exams have to take place at the same time.

Unless your school isn't in the U.K?


Yeah the exams at 9:15..... maybe you should check with people from your school to be sure :s-smilie:
Original post by Chris P Chicken.
It shouldn't be as all exams have to take place at the same time.

Unless your school isn't in the U.K?


yes it is, but no, they have to take place 30 minutes before or after the set time of 9:00.

all my exams start 15 minutes after the set time, my 9.00 ones are at 9.15, 1.30 ones are at 1.45

it makes no difference
Original post by cup
Cyanide - blocks 3rd electron carrier in electron transport chain, thus stopping 1st and 2nd carriers from being oxidised again. This means electrochemical gradient can't build up and hey presto no ATP is produced when this is tested on isolated thylakoids.

Dinitrophenol - acts as a hydrogen/proton carrier when introduced to isolated thylakoids it carriers protons back across the membrane meaning no electrochemical gradient can build up, and you guessed it no ATP is produced.

Or....

Isolate thylakoids, place them in a ph4 buffer, so electrochemical gradient is lost.

Place in new ph4 buffer with ADP+Pi and no ATP is made.

Place in new ph8 buffer with ADP+Pi and the electrochemical gradient is restored and ATP is made.

Teehee :smile:


This is about plants... oh dear :/

It's ok I think I somewhat get it... Thanks!!
Original post by Chris P Chicken.
It shouldn't be as all exams have to take place at the same time.

Unless your school isn't in the U.K?


Mine starts at 8.50am : / and its in the UK
Original post by --NWzD9--
All we need to know is that Red. FAD donates its protons to oxygen, as oxygen reacts with protons and electrons to form water, and that Red. FAD donates its electrons to the electrons carriers.


Thank you very much :smile:
look it doesn't matter. they have to start 30minutes either side of the set time. its not a big deal?
Original post by cup
They are in the medulla.... not sure about oblongata.

Carotid arteries is correct as well :smile:


Medulla doesn't make sense as there are many 'medulla's"

There's a medulla in the kidney and the adrenal glands, so don't make that mistake in the exam!
yes its the medulla oblongata
anyone have the mark scheme for january 2010?

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