AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011

Reply 1040

appleschnapps

^ Thanks for the top part of that graph; I couldn't understand the diagram we were given for the oestrus cycle.

Reply 1041

angel1992

Original post by Cyanohydrin

Yes, but they are more rare.

ok, so in invivo gene cloning we have to use spliced dna? how do we get that, from revere transcriptase and if so how can we use restriction endonuclease?

Reply 1042

D*Star

how do i revise the essay?

Reply 1043

diskohuelga

10

Anyone want to tell me the actual importance of T-tubules? What are they there for?

Reply 1044

alicetalbot

Original post by D*Star

how do i revise the essay?

View the past essay questions, write mind maps for what you know, check against the mark schemes - seems to be the way forward

Reply 1045

laura123

Does anyone understand restriction mapping?? Soooo confused :/

Reply 1046

tehsponge

11

Original post by diskohuelga

Anyone want to tell me the actual importance of T-tubules? What are they there for?

They basically deliver the calcium ions from the neuromuscular junction into the sarcoplasm, so that they can be used for the sliding filament mechanism. I learnt that today :awesome:

Well I got part of that wrong :ahee:

they deliver the wave of depolarisation throughout the muscle fibre, so that the sarcoplasmic reticulum calcium ion channels open, which allows them to enter the sarcoplasm.

(edited 12 years ago)

Reply 1047

angel1992

Original post by diskohuelga

Anyone want to tell me the actual importance of T-tubules? What are they there for?

t-tibules are needed because they ensure that depolarisation spreads to all parts of the muscle fibre, they are part of the muscles membrane that fold inwards so move into the sarcoplasm, if we didnt have them then, depolrisation would only occur for all the muscle fibres on the outside, depolarisation wouldnt get to the muscle fibres at the centre and so endoplsmic reticulum wouldnt be able to release the ca 2+ ions needed for contraction

Reply 1048

Cyanohydrin

13

Original post by diskohuelga

Anyone want to tell me the actual importance of T-tubules? What are they there for?

They are indentions on the membrane of muscle cells - essentially the impulse passes down the t-tuble. The tubule is connected to a sarcoplasmic reticulum by a protein complex - once the impulse reaches the protein complex it triggers the sarcoplasmic reticulum to release calcium ions - the calcium ions then bind to the troponin blah blah...

Reply 1049

sumsam

what would be your dream essay? mine would the different ways in which an organism uses ATP? or about basic cell cycle/structure. OR 'TELL ME 25THINGS YOU'VE LEARNT IN BIO! :biggrin:

Reply 1050

Cyanohydrin

13

Original post by angel1992

t-tibules are needed because they ensure that depolarisation spreads to all parts of the muscle fibre, they are part of the muscles membrane that fold inwards so move into the sarcoplasm, if we didnt have them then, depolrisation would only occur for all the muscle fibres on the outside, depolarisation wouldnt get to the muscle fibres at the centre and so endoplsmic reticulum wouldnt be able to release the ca 2+ ions needed for contraction

...well it's to do with the sarcoplasmic reticulum releasing calcium ions

this is an awesome video about it :biggrin:

http://www.youtube.com/watch?v=SauhB2fYQkM

Reply 1051

Superlogon

My beloved khanacademy has let me down for videos relating to unit 5 content but i found this video on SLIDING FILMAENT THEORY.
thought it might be useful for some as i don't know about you but i find watching videos far easy to understand than reading from the book. If you can see whats going on it's not usually that hard to understand!

http://www.youtube.com/watch?v=0kFmbrRJq4w

EDIT: just literally saw the link above and facepalmed. SO heres a second nice video! http://www.youtube.com/watch?v=zopoN2i7ALQ

(edited 12 years ago)

Reply 1052

Cyanohydrin

13

Original post by sumsam

what would be your dream essay? mine would the different ways in which an organism uses ATP? or about basic cell cycle/structure. OR 'TELL ME 25THINGS YOU'VE LEARNT IN BIO! :biggrin:

'Sorry we didn't have time to write an essay question - label this diagram of cell instead'

Reply 1053

Cyanohydrin

13

Original post by Superlogon

My beloved khanacademy has let me down for videos relating to unit 5 content but i found this video on SLIDING FILMAENT THEORY.
thought it might be useful for some as i don't know about you but i find watching videos far easy to understand than reading from the book. If you can see whats going on it's not usually that hard to understand!

http://www.youtube.com/watch?v=0kFmbrRJq4w

yay Salman Khan!! His voice is wisdom incarnate.

Reply 1054

User544981

10

Original post by sumsam

what would be your dream essay? mine would the different ways in which an organism uses ATP? or about basic cell cycle/structure. OR 'TELL ME 25THINGS YOU'VE LEARNT IN BIO! :biggrin:

my dream essay but it wont happen
however my dream essay wud be
sorry we forget to write an essay discuss why and tell us how stupid aqa is :smile:

Reply 1055

sumsam

Original post by Cyanohydrin

'Sorry we didn't have time to write an essay question - label this diagram of cell instead'

of an epithelial cell :smile:

even better just draw us a picture the better the pic the more marks you get. :rolleyes:

Reply 1056

Superlogon

Original post by Cyanohydrin

yay Salman Khan!! His voice is wisdom incarnate.

That beautiful man got me understanding pretty much my whole unit 4! Hardy weinberg before khan may as well have been greek. After his video i felt like slamming my head on the desk over how simple to formula is to use!

Reply 1057

Superlogon

Original post by sumsam

of an epithelial cell :smile:

even better just draw us a picture the better the pic the more marks you get. :rolleyes:

I'd definetly draw Darwin riding a dinosaur shouting 'DISPROVE THIS'. While the dinosaur proceeds to eat adam and eve.

Reply 1058

Reck16

6

No way I can't draw anything. Except a stick. I draw a mean stick.

Dream essay is : "Glucose and it's uses in organisms", or something along those lines. Could mention metabolism, amylase and maltase, diabetes and its control, regulation of glucose in the blood (insulin, glucagon, adrenaline...) as well as the obvious photosynthesis and respiration. So much to talk about.