Year 12s: what will be the first way you research your future options? >>

Edexcel A2 Biology Unit 5 (6BIO5) - 22/06/2011- OFFICIAL THREAD !

Scroll to see replies

yup ! decarboxylases is righteo too !!

never hear dof phosphofr.......wa ??!
explain its function please

Phosphofructokinase is the enzyme responsible for phosphorylating the hexose-phosphate in the phosphorylation of glucose in glycolysis (it actually phosphorylates fructose-phosphate to fructose-diphosphate, but we don't have to learn all the little bits of gycolysis like the isomerism step and the product names - just that glucose is phosphorylated to activate it and stop it leaving the cell, then split to give 2x GALP, then converted through a series of intermediates to produce pyruvate, and obviously the amount of ATP produced and NAD reduced). It is the rate determining enzyme of respiration - the rate of respiration is dependant on how fast this enzyme can phosphorylate the sugar. High levels of ATP and/or citrate inhibit phosphofructokinase (reduce rate of respiration, slowing production of pyruvate), low levels of ATP/citrate or high levels of ADP activate the enzyme (increase rate of respiration and production of pyruvate).

Reply 3681

19941994

Original post by This Honest

awww silly girl

Lol thats not very nice

This was posted from The Student Room's iPhone/iPad

Reply 3682

19941994

Original post by i Pav i

Does anyone know ALL of the core experiments we should know for Unit 5?

e.g. The woodlice and measuring oxygen uptake..

There's other ones that I can't remember?

Thanks!

I think its just the woodlice, habituation (snails), effects of exercise on tidal volume and breathing rate, the spirometer one (measuring rate of O2 uptake), and thats all i have in my notes :smile:

think thats it

This was posted from The Student Room's iPhone/iPad

Reply 3683

i Pav i

Original post by 19941994

I think its just the woodlice, habituation (snails), effects of exercise on tidal volume and breathing rate, the spirometer one (measuring rate of O2 uptake), and thats all i have in my notes :smile:

think thats it

This was posted from The Student Room's iPhone/iPad

The woodlice one came up in Jan 2012.
The spirometer came up in June 2011.

So I think I'll focus on the habituation!

Reply 3684

This Honest

Original post by 19941994

Lol thats not very nice

This was posted from The Student Room's iPhone/iPad

But the thread title says edexcel....

Reply 3685

Kylewalker346234

Explain how an increase in Heart Rate occurs from exercise (4 Marks :smile:

)

Reply 3686

This Honest

Original post by ConnorB

Explain how an increase in Heart Rate occurs from exercise (4 Marks :smile:

)

more co2 produced
chemoreceptors detect increase in co2 and send nerve impulses to medulla
medulla sends nerve impulses to heart via sympathetic nervous system to depolarise SAN
depolarisation of SAN increases which increases the heart rate
???

Reply 3687

DarrenDM

Can someone explain what a transcription factor is and does?

Reply 3688

ghogho

Original post by This Honest

the chemoreceptors are resposible for the ventilation rate not the heart rate when it detect that there is an increase in the co2 and decrease in the ph it sends to the inspiratory center in the medulla