AQA AS Biology Unit 1 Unofficial Mark Scheme

6B is definately

ph8 worked better with amylase so more maltose is produced so the water potential in B (ph 8) is decreased. ph2 was less efficient so less maltose was produced than in B, the water outside entered the partially permiable membrane by osmosis to flatten the concentration gradient as there were more molecules in B, more water entered B making the water level higher than A

hydrolysis of starch create more molecule. osmosis is about concentration gradients. if there is a higher concentration solution in B then more water will enter.

Reply 45

Original post by dhillon1

doesn't amylase break down starch into glucose

no into maltose. then maltase into glucose.

Reply 46

Original post by MediterraneanX

Do you think you'd still get two marks for saying the the first two bits without talking about osmosis (yes i'm an idiot)

osmosis would only be worth one of the marks, so u should get some, yea.

Reply 47

Original post by dhillon1

yeah thats what i meant maltose :smile:

.
you said the enzyme breaks down starch into amylase?

i didnt say anything, u werent replying to me :wink:

Reply 48

swiftylol

18

I didn't write about osmosis either, even tho I read the partially permeable membrane bit :facepalm:

Reply 49

I think 5a was something like using the graph, describe the effect of cyanide on the uptake of sodium ions, but I don't think they actually used the world describe. Maybe determine?

Reply 50

Chicken Bacon

Original post by MediterraneanX

Do you think you'd still get two marks for saying the the first two bits without talking about osmosis (yes i'm an idiot)

yeah you would, osmosis would be the final mark.

Reply 51

Original post by bad8oy

dont you mean amylase breaks down starch into glucose?????

maltose*

Reply 52

Original post by bad8oy

dont you mean amylase breaks down starch into glucose?????

it breaks it down to maltose

Reply 53

Original post by MediterraneanX

I think 5a was something like using the graph, describe the effect of cyanide on the uptake of sodium ions, but I don't think they actually used the world describe. Maybe determine?

2 marks.

one would be for it slowed the rate of reaction
other would be for reduced the number of ions that could be absorbed.

Reply 54

xOsugaplumfairy

I thought the peptide question would be that it cant be transported my facilitated diffusion because it can't bind to co-transport protiens as it doesnt have the complementary shape? So the co-transport proteins wont let it through..

Reply 55

bad8oy

14

Original post by MediterraneanX

it breaks it down to maltose

woops i messed that question up aswell then :frown:

and question 7 screwed me. :'(

Reply 56

Original post by britash

For the one about the drug and coeliac disease and why they should think before they give it to patients.
Could you put long term effects and if the side-effects outweigh the benefits?

Do you mean the things they'd have to consider? I put the long term effects and whether they're immuno-depressed (pretty sure that was wrong - go me for regurgitating previous mark schemes). Usually they accept age, ethnicity etc but I couldn't really see how that was relevant in this case?

Reply 57

Chicken Bacon

Original post by bad8oy

dont you mean amylase breaks down starch into glucose?????

yeah lmao xD

Reply 58

Original post by xOsugaplumfairy

I thought the peptide question would be that it cant be transported my facilitated diffusion because it can't bind to co-transport protiens as it doesnt have the complementary shape? So the co-transport proteins wont let it through..

co transporters arent used in diffusion. only in active transport. if it asked bout diffusion its wrong.

Reply 59