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ALL CIE BIOLOGY DOUBTS HERE !!!

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Vampire-Love4ever:

--- Quote from: Amelia on May 16, 2011, 06:45:01 pm ---An action spectrum is a graph showing the effectiveness of different wavelengths of light in stimulating the process being investigated. An absorption spectrum is a graph of the relative amounts of lights absorbed at different wavelengths by a pigment.

An action spectrum for photosynthesis is shown together with an absorption spectrum for the combined photosynthetic pigments.

http://5e.plantphys.net/images/ch07/wt0701c.png

NOte the close similarity, which indicates that the pigments, cholorophylls in particular, are those responsible for absorption of light in photosynthesis.

--- End quote ---

Thanks for your help. :)

NidZ- Hero:

Explain why sickle cell anaemia is common in areas where malaria is endemic ?
0/n 6b p2
 

**RoRo**:

--- Quote from: Amelia on May 16, 2011, 06:36:27 pm ---Like MK said, Cu+ ions are not the shape of the sucrose so they do not attach themselves in the active-sites of the enzymes but elsewhere in the enzyme molecule. They alter the shape of the enzyme in such a way that the active site can no longer accomodate the substrate. As the substrate & inhibitor molecules attach on different parts of the enzyme, they are not competing for the same sites (non-competivite). Also, metal ions break the disulphide bonds(that help maintain the shape of the enzyme molecule). This causes the enzyme molecule's structure to be irreversibly altered.

Attach the questions please.  :-\

--- End quote ---

What I meant is how would you know the shape of Cu ions, like why can't you say that it competes with the substrate and it becomes a competitive inhibitor?

I don't have a soft copy of the paper, so I'll type the questions for you in a while, or probably scan it for you.

Thanks Amelia and Master_Key :)

**RoRo**:
I've attached the paper here in 2 parts.

Sue T:

--- Quote from: Vampire-Love4ever on May 10, 2011, 09:57:21 pm ---Biology Paper 5, specimen paper:
Q2. How to measure the curvature???

--- End quote ---
ok so as promised, Vampire-love - here r th answers 2 ur previous posts ;)
first for ths one u dont really need 2 bother about that - there are lots of other points you could write - but anyways you can always say to use a protractor to measure th curvature - just state it like that u dont need to include so much detail  :-\

1bi and ii) the marking scheme is messed up - they can always  be rong u no!
here is wat u shod get: mean for tissue A = 56  sA= 2.357 and SM= 0.75
mean for B = 123.3 sB=2.312  and SM= 0.73
the bar chart will become hard 2 draw with its error bars once you get these values - but dont worry its their fault :p its just a specimen paper...
thats it - good luck 2moro ;) cya!

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