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nano9595 said:i m freaking out about the exam tomorrow i just feel that i m going to mess things up
gud luck to u all :good:
mrpaudel said:Somebody plz make the question clear to me...and then answer plz...!!
There are certain growth factors and regulators so cells cant divide whenever they want!AAestar said:mrpaudel said:Somebody plz make the question clear to me...and then answer plz...!!
Well, if cells are to divide whenever they want, they would grow into an irregular mass of cell, meaning a tumour would be formed. So elaborate that a lil. ^^
atleast u have mark schemes!!!hassam said:agreee reading CIE markschemes of biology is hell of a job.......
byhn222 said:hey guys, i had a question, in an exam is it okay to go underneath the lines given to answer a question, if let's say you cross something out in your answer and change it so you need more space? and another question, in an exam i had to draw a table, and i drew it in pencil, which i know is okay, but i filled in the headings with a pencil too. would i lose the marks?
A non-competetive inhibitor doesnt compete with the substrate for the active site of the enzyme, it bind to the allosteric site of the enzyme instead, alters the shape of the enzyme so it can no longer bind to its substrate. Therefore, incresing the substrate concentration won't increase the rate of the reaction.pennies said:why is the answer A not B??
nano9595 said:pls help my exam s tomorrow
could anyone pls explain to me the following questions: :unknown:
http://www.xtremepapers.com/CIE/International A And AS Level/9700 - Biology/9700_s11_qp_11.pdf
1)question 13 the answer is A why couldnt it be B
2)question 14 the answer is C why couldnt be A , isnt the active site changed during non competitive inhibition
3)question 16 the answer is B why couldnt it be D
thnx in advance
rviboy said:1) as all these structure's gives the enzyme its characteristic 3 d globular shape used to bind with the substrate so all of them are important in determining its specificity. quaternary structure gives the enzyme its globular coiled shape. hydrogen, ionic, di sulphide and hydrophobic interactions all important in attaching with the substrate
2)yes non competitive inhibitor alters the active site. but in this case the active site is already occupied by the substrate molecule :/
3) the membrane protein uses energy from ATP in mitochondria for the exchange of substances against the gradient and the membrane protein to my knowledge is not found in the mitochondrial membranes but i m not sure!
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