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AQA A-level Biology Unit 1 26th May 2016

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Original post by gcsekid
No I mean water, because water is released from hydrolysis of trigylcerides. In a triglyceride theres already three fatty acids so they would have no net change after being hydrolysed coz theres atill only three. However there is addition of water which is only present after hydrolysis


Quoting Collins Student Support Materials for AQA AS Biology Unit 1: Biology and Disease- p.19 Examiners' Notes Remember that fatty acids really are acidic and will therefore cause a lowering in pH when they are released during digestion (hydrolysis).
Original post by studynerd4
I put this


same sxc
Only about 10 students sat this resit exam at my school.

It was quite a weird paper, I thought.

Quite liked the last two 5 markers.

Didn't like the Ebola stuff.

PH stuff was a bit strange.

I'd also agree with the user who said it was a better paper than last year's though. Hmm..
Original post by CourtlyCanter
Quoting Collins Student Support Materials for AQA AS Biology Unit 1: Biology and Disease- p.19 Examiners' Notes Remember that fatty acids really are acidic and will therefore cause a lowering in pH when they are released during digestion (hydrolysis).

Oh ****
Please AQA dont check Collins
Hopefully they give the OR option too so were both happy
Original post by CourtlyCanter
Quoting Collins Student Support Materials for AQA AS Biology Unit 1: Biology and Disease- p.19 Examiners' Notes Remember that fatty acids really are acidic and will therefore cause a lowering in pH when they are released during digestion (hydrolysis).


get in!!!!!!
oooooooh yaaaaaaa beybeh
1 mark in the bag
shabang
On the last question I talked about how oxygen is a small, fat soluble, uncharged molecule that can pass through the fluidity if the phosphlipid bilayer
I put that the chloride ions are charged, water soluble and large therefore cannot diffuse through the membrane
I talked about facilitated diffusion with carrier proteins and diffusion with water filled protein channels
Do you think this is okay for all 5 marks?
I didn't like the paper. I enjoyed doing past papers for BIOL1 and this caught me off guard.

NK
for the one about 'why did ph level stay constant?' couldn't you say all the lactose had been hydrolysed?
Original post by NK18444
On the last question I talked about how oxygen is a small, fat soluble, uncharged molecule that can pass through the fluidity if the phosphlipid bilayer
I put that the chloride ions are charged, water soluble and large therefore cannot diffuse through the membrane
I talked about facilitated diffusion with carrier proteins and diffusion with water filled protein channels

Do you think this is okay for all 5 marks?
I didn't like the paper. I enjoyed doing past papers for BIOL1 and this caught me off guard.

NK


Heres how I would break down the 5 marks
Oxygen crosses membrane via simple diffusion
Oxygen is lipid soluble
Chlorine ions too large to cross membrane
So use channel protein in the phospholipid bilayer
For facillitated diffusion
Down a concentration gradient
Original post by gcsekid
Oh ****
Please AQA dont check Collins
Hopefully they give the OR option too so were both happy


Mate the revision guide itself advertises this on its front cover- 'Checked by an AQA Principal Examiner'

Hope we both get the marks.
(edited 7 years ago)
Original post by gcsekid
Heres how I would break down the 5 marks
Oxygen crosses membrane via simple diffusion
Oxygen is lipid soluble
Chlorine ions too large to cross membrane
So use channel protein in the phospholipid bilayer
For facillitated diffusion
Down a concentration gradient


and the polarity BS
AQA can fok their nan
Original post by gcsekid
Heres how I would break down the 5 marks
Oxygen crosses membrane via simple diffusion
Oxygen is lipid soluble
Chlorine ions too large to cross membrane
So use channel protein in the phospholipid bilayer
For facillitated diffusion
Down a concentration gradient


yes I wrote all of that and described both facillitated diffusion with carriers proteiins and water filled channels
Original post by NK18444
yes I wrote all of that and described both facillitated diffusion with carriers proteiins and water filled channels

Trusting AQA and the fact that I memeorised mark scheme answer (Sad I know) they give basic marks for 2 words and u dont wana miss it out. There will be about 7-8 points and 5 of em shud give u marks
Original post by chiwah
same here! - it messes up the ionic bonding and changes tertiary structure


surely if the enzyme was denatured, the amino acids would be released and since amino acids have a carboxyl group it would make it more acidic n lower the ph?

I put that all the substrate was used up
Original post by Bennyab
Should not be fed foods high in sugar or drinks high in sugar, would affect results

Add lactase to hydrolyse lactose or heat (I out both)


for what they shouldn't eat i put foods containing lactose (e.g. dairy products), since they were measuring the symptoms of lactose intolerance remember other sugars would not effect the results and cause symptoms? not sure tho
What did everyone get for the actual size of the mitochondria ??
Original post by yourmatej
for the one about 'why did ph level stay constant?' couldn't you say all the lactose had been hydrolysed?


Triglycerides were being hydrolysed, not lactose


Posted from TSR Mobile
Original post by georgestonham1
What did everyone get for the actual size of the mitochondria ??

2.8um
Original post by georgestonham1
What did everyone get for the actual size of the mitochondria ??


2.8


Posted from TSR Mobile
Original post by Bennyab
Triglycerides were being hydrolysed, not lactose


Posted from TSR Mobile


yeah thats what i meant. would that be right baby?
Why would the enzyme denature it was at 20 degrees? So it wouldn't denature..
Triglycerides limiting factor more correct

I put same as gcse kid

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