AQA Higher Biology

Hi everyone

Just one question really. Does anyone remember that question on the Biology test about putrefying bacteria? Well if anyone does, what was the other type of bacteria mentioned? I think it was denitrifying, but it might have been nitrifying bacteria. I cant remeber which i talked about and im scared i talked about the wrong type.

Thanks for any responses

Reply 1

Mth15

It was nitrifying im afraid, so the answer was that putrifying bacteria convert the proteins in the dead plant into ammmonium compunds and then the nitrifying bacteria turn the ammonium comounds into nitrates, which the plants can use

Reply 2

frogout

It was nitrifying.

I proper messed up that question, I had no idea what putrefying was so I said it turned carbon into carbon dioxide!!! O_O

Reply 3

mj2

I think that turning carbon into carbon dixoide thing is right because if i can remember, the question said how the two types of bacteria recyle products to recyle 'CARBON DIOXIDE AND NITROGEN', so one of the bacteria must have turned carbon into carbon dioxide.

Reply 4

purple-girl

Putrefying turnes ammonium compounds into nitrates. I dunno how carbon comes into it, I think I said that the bacteris respire, producing carbon dioxide which the plants can use again in photosynthesis. But it was a really horrible exam!

Reply 5

Mth15

The carbon recycling part needed you to say that the bacteria break down the organic compounds to use for respiration (using enzymes), which produces CO2, which is used by plants to photosynthesise and metabolise more complex organic molecules such as glucose

Reply 6

Mth15

And also, putrefying bacteria turns proteins into ammonium compounds and then it is nitrifying bacteria that turn the ammonium compounds into nitrates

Reply 7

frogout

I think I got 0 in that question actually... which is like 4% of the total marks... add that to the rest of my mistakes... I definately didn't get an A* ='(

Reply 8

Pumpkin_Howie

in the first part of the answer is said the nitrifying bacteria broke down the ammonia compunds into nitrates which could be used by the plants, but i totally messed up that whole carbon thing. will i stil get some marks for getting it halk right??

Reply 9

CrystalP

I just made up a load of rubbish on that question.
Disappointing really :|

Reply 10

* Dain Bramaged *

i didn;t think we had to talk about carbon??? i only wrote about putryfing and nitrifying bacteria. ammonium compoads to nitates. sugar + nitrates = protein.... is tht wrong?

Reply 11

Isometrix

my answer was

- nitrates taken up by plant by active transport
- animals eat these plants so the nitrates are fixed in them, the animals also respire releasing CO2.
- animals use nitrates to form amino acids which are then turned into protein based urea.
- urea is converted to ammonium compounds by putrefying bacteria.
- ammonium compounds converted to nitrate ions by nitrifying bacteria.

tbh i dont knw where the carbon bit fits in so i just made up the respiration bit :confused:

Reply 12

* Dain Bramaged *

this is aqa higher seperate science yer>?????? in the question i only read about nitrogen n ammonia...nuffin to do wif caron so y is everyone on bout carbon n stuff??????????????
was only 4 marks will only need:

•

putrifying bacteria

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protein to ammonium

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netrifying is ammounium to nitrates

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nitrates taken up by plants and turned to protein