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A level Biology: Post your doubts here!

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Hi, I have some questions to ask about the AS past papers for biology and specifically where they seem to contradict the book i am working from ( which is the biology coursebook by Mary Jones Richard Fosbery Jennifer Gregory and Dennis Taylor. ) firstly in this book the antibiotic penicillin is referred to as a non-competitive inhibitor ( on page 62) ( as it bonds permanently to the active site of enzymes used in cell wall synthesis ) but in the past paper 2012 October November specimen paper 23, question 2, c (ii) it is stated that "Penicillin acts as a competitive inhibitor" . also the second point on which i am somewhat uncertain is, when referring to normal cells, that is cells not currently undergoing mitosis or meiosis, is it not incorrect to refer to the cells as containing chromosomes? ( because the genetic material of the cell is contained in chromatids in the nucleus, which are in the form of loosely coiled chromatin, and so cannot contain chromatin, )
 
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Manage your time!
Revise the structures of the plant and how to draw a plan diagram
Beside each label put a small note
and good luck :)
You are of precious help dear. Thank you again :)
putting a lil note means annotation.
if the question doesnt ask for annotation then DO NOT annotate. only label.
for labelling...even if theydint ask to label..u shld label.
 
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Hey .Can anyone please answer this question.Thanks a lot

How the structure of DNA makes it suitable for replication
its double stranded joined by hydrogen bonds between complementary base pairing. Therefore each DNA strand can act as a template for formation of complementary strand by being paired with complementary neucleoutides to produce two identical molecules of DNA.
 
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14 Some inhibitors of enzyme reactions bind to the enzyme / substrate complex.
Which statements about this type of inhibition are correct?
1 The active site changes shape
2 The inhibitor is non-competitive.
3 The initial rate of reaction is reduced.
4 maximum rate of reaction (Vmax) is increased.

A 1 and 2 only B 1and3only C 2and3only D 2,3and4only

How is the answer C?
I don't understand that if the active site is not changing shape then how is the non competitive inhibitor causing the rate of reaction to decline?
 
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