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

I remember writing stroke volume somewhere :/

Also unofficial mark scheme anyone?

paper first

Noone has it yet?

What does inshallah mean?

what is the answer for the question that asked about EPO production in Q7 ??

Hi guys, did anyone else put in that pH q about muscles that fast twitch muscles respire mainly anaerobic and slow twitch aerobic... therefore lower pH in anaerobic conditions i.e. more lactic acid and so fast twitch muscles more adapted to pH6?
Also, the only q that I couldn't answer was the troponin one... the q said that taking troponin from fast twitch and putting it in slow twitch made it act like fast twitch (or v.v. i can't remember). I can't find it in any of my (3) textbooks... anyone have an answer?

Yssss Jen, i did write exactly this for the pH qn and i believe it is ryt, and then i went on by explaining one other point which i can't atm remember....

Well, as far as i think, in the troponin qn we had to answer from our own basic knowledge and cover a point or two from the spec....so i said that troponin is a protein and it's tertiary and quaternary structure determines whether Calcium ions bind to it or not; it's structure is same whether it is found in either of the two types of muscle fibres therefore the binding of calcium ions to troponin is not affected by the type of muscle fibre the troponin is found in....i hope this is ryt....these points were the only ideas that came into my mind at that time....what did u write for this qn?

Cheers!

Hi guys, did anyone else put in that pH q about muscles that fast twitch muscles respire mainly anaerobic and slow twitch aerobic... therefore lower pH in anaerobic conditions i.e. more lactic acid and so fast twitch muscles more adapted to pH6?
Also, the only q that I couldn't answer was the troponin one... the q said that taking troponin from fast twitch and putting it in slow twitch made it act like fast twitch (or v.v. i can't remember). I can't find it in any of my (3) textbooks... anyone have an answer?

The strength ran in the mother's side of the family. It didn't say anything about the father's side, so I assumed he had no such mutation. Talking in terms of genotypes, that is definitely an AA genotype.



The question asked how the boy "could have obtained this mutation." The article said the boy "had a mutation in both copies of the gene". It also said the mother had "a mutation in one copy of the gene". There is no reference to the father having such a mutation, but there is a reference to the mother. Conversely, if the father had been mentioned and the mother had not, it's not accurate to say the mother would have the mutation.

I've always been taught to work on information I have, not information I would like to have. So, in that case, I worked on the premise that they boy might have obtained the mutation on his own. After all, it asked to suggest a way, not give a way.

I thought the question asked why the fast twich fibres replaced with slow twich troponin had the same sensitivity as slow twitch?! They didn't stay the same did they?

I said that fast twich are used for short bursts of rapid movement so have more sarcoplasmic reticulum and release more ca2+ ions which the troponin is more sensitive to and more abundant to allow for rapid contraction ,.. then i wrote the relevent but of the sliding filament theory out. then I said so replacing it with slow twitch troponin would mean more (the same amount as slow twitch) ca2+ is required for contraction to the same degree.

I hope I didn't completely misinterpret the question ... But the whole abundance/sensitivity thing I just made up cause I had no idea how to answer it with texbook knowledge

According to that, the mother should also be a superhuman as well. Which the information did not say.

The article says the mother had one mutation and had some excess strength. It also said the boy "was the first to lack any myostatin at all. You can assume from this that the boy was different to his mother.