Edexcel A2 Biology Unit 5 (6BIO5) - 22/06/2011- OFFICIAL THREAD !

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19941994

One of the problems with this exam is so many people do well because they need the grades to get into uni and is often their most important exam, this leads to grade boundries being slightly higher :frown:

I want people to do well, but not to cost me my place at uni :frown:

True :/ the grade boundaries are normally higher than unit 4 as well! :frown:

This was posted from The Student Room's iPhone/iPad

Reply 4021

Bright

Original post by 19941994

Well i actually have no idea lol, i did the whole A level in one year so i havent got my results for the coursework, or units 2 and 4! So to be on the safe side I need to do well in this exam incase i did badly in the others, so yeah aiming for an A lol. What about you?

This was posted from The Student Room's iPhone/iPad

Yikes!

Good luck, hope you get it! :] that's like me and chemistry.. I only know I got an A for unit 1 and courseworks, hope the same in exams :colondollar:

and I need a 126 UMS to get an A, so a B in this I think. I'm assuming my coursework was utterly crap so the higher the better :l

Reply 4022

nadzzdan

Original post by ghogho

aha okay thx
but the qu is for 3 marks so do u knw further explanation?

if the ventricles contract from bottom upwards it means the blood will be pumped into the aorta and pulmonary artery. this is important because this way all the blood is pushed up at once so there is more blood pumped at each stroke (stroke volume is high). lastly if it contracts from top to bottom blood would be pushed down essentially damaging cardiac cells... i cant think of anything more...

Reply 4023

C_Lauren

can someone please give me a bullet point outline of the sliding filament theory?

Reply 4024

nadzzdan

Original post by iesians

GOOSHH it doesnt make sense.
hyperpolarisation is that its more negative inside right ??!?!?
so how is this corrected ??
Na/K pump pumps Na+ ions OUT and K+ ions in right ? but K+ ions again diffuse out due to permeability. so overall theres more positive out !? THIS ISNT HELPING AT ALL ! its making inside even more negative ??! BIOLOGY FAIL :tongue:

when membrane is hyperpolarised the PD is about -90mV. at this the K+ ion channels close so only k+ ions can move in and out through diffusion. now remember K+ ions have a positive charge. because the inside is more negative the k+ ions are ATTRACTED inside and diffuse this way. forget Na+ ions right now because their channels closed when membrane was repolarising. If the inside is more negative MORE K+ ions will be diffusing. until it reaches -70mV this happens. after it reaches resting potential you know the story... :smile:

Reply 4025

BastardOranges

Can anyone explain the wave of depolarisation?

I feel like I only vaguely understand it :frown:

Reply 4026

iesians

Original post by nadzzdan

OHWOW ! makes perfect sense !
but i havent seen i this anywhere not in book not inr ev guide ??! :confused:

what about the Na/K pump ?! is it even involveed in ehre ???!?!

Reply 4027

Hanz_a93

How much ATP is produced on aeroboc respiration? SNAB book says 36 :/ and also some other figure :s-smilie:

cgp says a lower amount i think. confusingg

Reply 4028

hannah_27

Original post by BastardOranges

Can anyone explain the wave of depolarisation?

I feel like I only vaguely understand it :frown:

A stimulus reaches a membrane
This causes sodium ion channels to open
Sodium channels diffuse into the membrane
This causes the inside to be more positive and the outside to be more negative
It the potential difference is above the threshold, the membrane is depolarised and an action potential is created

Reply 4029

VickyDoodle

Original post by Hanz_a93

How much ATP is produced on aeroboc respiration? SNAB book says 36 :/ and also some other figure :s-smilie:

cgp says a lower amount i think. confusingg

Always go by what the SNAB book says, CGP's for a different spec.

Reply 4030

M Kh

Original post by ishtarbb

Sorry but can you send them to me as well? i mean if you not gonna upload them here :tongue:

im a private student and got really few resources :s-smilie:

thank you so much!

Original post by This Honest

You would be doing me a massive favour if you could send me the notes too
Congrats on that awesome score.

Original post by ghogho

thank u sooooooo much :biggrin:

Original post by greenhamrolls

Hi there, I saw you that you might be able to help with some revision materials etc? I'm so stressed with this exam and I only need a C, but I just can't get the questions right. I've learnt most of the stuff from the textbook but i'm finding it so difficult to apply it to the paper.
I literally just need like 55-60% (or higher :wink:

)to be able to get what I need so I can go to uni..
Could you offer any advice?

Original post by 19941994

Also would you be able to send me the revision notes today please? Would appreciate it! :smile:

Original post by d_94

What do you think is gonna come tomorrow?

Original post by ferra

me want too.do quote me as well :biggrin:

Guys here are the unit 5 topic 8 notes: http://www.mediafire.com/view/?0axz4vqmxxyq1at
All credits to the original uploader. All rights reserved.

If you like my ntes, please like this page: www.facebook.com/6bi04

(edited 11 years ago)

Reply 4031

nadzzdan

Original post by iesians

OHWOW ! makes perfect sense !
but i havent seen i this anywhere not in book not inr ev guide ??! :confused:

what about the Na/K pump ?! is it even involveed in ehre ???!?!

the Na/K pump is always pumping it never stops... i didnt look it up but from what i remember this seems to be the most logical answer...

Reply 4032

nadzzdan

Guys does anyone understand JAN 12 paper question 1aiii)?

Reply 4033

M Kh

Original post by ishtarbb

Sorry but can you send them to me as well? i mean if you not gonna upload them here :tongue:

im a private student and got really few resources :s-smilie:

thank you so much!

Original post by This Honest

You would be doing me a massive favour if you could send me the notes too
Congrats on that awesome score.

Original post by ghogho

thank u sooooooo much :biggrin:

Original post by greenhamrolls

)to be able to get what I need so I can go to uni..
Could you offer any advice?

Original post by 19941994

Also would you be able to send me the revision notes today please? Would appreciate it! :smile:

Original post by d_94

What do you think is gonna come tomorrow?

Original post by ferra

me want too.do quote me as well :biggrin:

Guys here are the unit 5 topic 8 notes: http://www.mediafire.com/view/?0axz4vqmxxyq1at

All credits to the original uploader. All rights reserved.

Reply 4034

hannah_27

Original post by Hanz_a93

How much ATP is produced on aeroboc respiration? SNAB book says 36 :/ and also some other figure :s-smilie:

cgp says a lower amount i think. confusingg

Glycolysis produces 4 ATP and uses 2 ATP - so makes 2 ATP
Plus it made 2NADH - each NADH makes 3 ATP, so 3x2=6 ATP
GLYCOLYSIS = 8 ATP

Link reaction makes NADH - but this whole thing happens TWICE as there are two pyruvate molecules, so 2 NADH = 3x2 ATP
LINK REACTION = 6 ATP

Krebs cycle makes 2 ATP as it reduces from 5C to 4C
It makes 6 NADH = 3x6 = 18 ATP
It makes 2 FADH = 2x2 = 4 ATP
2 ATP + 18 ATP + 4 ATP = 24 ATP
KREBS CYCLE = 24 ATP

TOTAL YIELD - 8 + 6 + 24 = 38 ATP

Reply 4035

lagoom

Original post by charlypennington

can someone please give me a bullet point outline of the sliding filament theory?

calcium binds to troponin on actin filament
causing troponin to change shape and move tropomyosin which it is attached to exposing the actin myosin binding sites
myosin globular head attaches to actin on the binding site
ADP and inorganic phosphate which are bound to the myosin head is released causing the myosin globular head to change shape
the myosin nods forwards causing the actin to move along the myosin
ATP attaches to the mysoin head, causing it to change shape and detach from the actin, ATPase is acitvated in the mysoin head which also needs calcium ions to be activated, the ATP is hydrolysed
energy is provided for the myosin to go back to its original position

Reply 4036

BastardOranges

Original post by hannah_27

Thanks for your reply, but I was talking about the wave of depolarisation - how the action potential moves along the neurone

Reply 4037

ZTSR

Electron transport chain.

How is high concentration of H+ ions maintained in the inter membrane space ?

:smile:

Reply 4038

lagoom

Original post by BastardOranges

Can anyone explain the wave of depolarisation?

I feel like I only vaguely understand it :frown:

depolarisation in a region causes depolarisation in an adjacent reason, this is beacuse when a certain region is being depolarised, sodium ions diffuse side ways to the adjacent region, the presence of the sodium ions causes the adjacent region to become depolarised, gated sodium channels open, as more and more sodium ions diffuse into the axon more and more channels open- positive feedback