The Student Room Group

WJEC BY1 May 21 2013

Scroll to see replies

Reply 40
Original post by mli26
Was the reason why enzymes speed up reactions that it allows activation energy? Or did you have to say more?

Its because it lowers the activation energy so there are more enzyme substrate complexes are formed so increases rate of reaction I think. I think just writing lowers activation energy may get you the mark.
Damn it, I wrote that enzymes can form more enzyme substrate complexes after releasing the product so they have a high turnover number and can form lots of products per minute. Is that right also or?


Posted from TSR Mobile
Reply 42
Original post by imgonnafail
Damn it, I wrote that enzymes can form more enzyme substrate complexes after releasing the product so they have a high turnover number and can form lots of products per minute. Is that right also or?


Posted from TSR Mobile

Technically it's right but I think to get the mark you might have to say something about lowering activation energy. Cant be too sure though. Just hope you get a lenient marker! :smile:
Reply 43
what did you get for what type of plant cell was shown i wrote leaf. and for what tissue cell shown i wrote tendon?
Reply 44
Original post by imgonnafail
I put that the enzymes themselves are insoluble because they're globular proteins, and then that they'd be too spread out if not clumped so there is less chance of a successful collision>enzyme substrate complex>product made so there would be a lower rate of reaction. Probably wrong though, it was a complete guess.


Posted from TSR Mobile


Enzymes/ globular proteins are soluble though? Fibrous aren't.

I said that when a substrate bonds to an enzyme, the enzyme alters shape slightly and this distorts a bond in the substrate, lowering the activation energy required to break it.


Posted from TSR Mobile
I wrote leaf too.

And oh, crap.


Posted from TSR Mobile
Reply 46
I wrote mesophyll, hope that's right:smile:
Reply 47
Ah.. I wrote the root tip of plants.
Reply 48
I wrote Root tip for the Mitosis plant cell question
Reply 49
I wrote down roots but I think i might lose a mark cause the board is quite picky :frown:
does anyone reckon there will be an unofficial mark scheme up soon ?
Reply 51
I'm hoping someone will upload an unofficial mark scheme tomorrow, don't think I can wait til August for my results!!
Reply 52
for functions of protiens did you write intinsic used for movement of ions and large molecules across membrane via facitlaltated diffusion and active transport and glycoproteins on outside act as recognition sites
Reply 53
Original post by melissa164
I'm hoping someone will upload an unofficial mark scheme tomorrow, don't think I can wait til August for my results!!


omg me too.
what do you think grade boundaries will be like ?
Original post by sophialouise
what do you think grade boundaries will be like ?


Hopefully low enough for me to get a B ahaha


Posted from TSR Mobile
Original post by imgonnafail
Hopefully low enough for me to get a B ahaha


Posted from TSR Mobile

I hope so too. someone seriously needs to get on with this unofficial mark scheme I cant wait
Reply 57
I put root tip for the mitosis tissue one. Could everyone find TWO differences between the two ER photos. I wrote one is rough-with ribosomes and the other is smooth-without....
Original post by baddeleyh
I put root tip for the mitosis tissue one. Could everyone find TWO differences between the two ER photos. I wrote one is rough-with ribosomes and the other is smooth-without....
Same, it was only 1 mark like the rest of the photograph questions
Do you think for the DOX question it would be sufficient to say that the proteins change shape therefore cannot function in channeling key molecules like magnesium?

Quick Reply

Latest