OCR Biology F214 Communication, Homeostasis and Energy Friday 22 June 2012

Original post by CollateralElement

Is that it? And that's collectively known as Selective Reabsorption? What if they ask a QWC on it? :frown:

how selective reabsorption happens

Sodium ions moved out cells in proximal convoluted tubule by sodium potassium pump
low sodium ion conc in the cells of pct
sodium from tubulue fluid moves in along with glucose and amino acids from tubule fluid via facillitated diffusion via co-transporter proteins
Glucose and amino acids in the cell of the PCT cause teh water potential of the cells to incerease
they then diffuse out into the tissue fluid which has a low water potential
and then move into the bloodstream
some water may also be reabsorbed as tubule fluid has high water potential and cells of PCT has low water potential therefore some water may be reabsorbed by the blood capillary via osmosis

Add in some structual things so
many mitochondria present provides ATP for active processes
PCT membrane highly folded to give microvilli which give large surface area
opposite membrane folded to give large surface area
Sodium potassium pump present to pump 3 sodium out for every 2 potassium going in. Requires ATP

and a few extra points from old spec mark schemes

Vitamins reabsorbed
chloride ions reabsorbed
OH and state the obvious
glucose reabsorbed
amino acids reabsorbed
some water reabsorbed

You wont get anything more than a 6-8 marker should it come on I'm gonna be srprised if theres a question larger than that

Reply 982

Might go to sleep in about 5 or 10 minutes. I'm already so tired and starving. Can't have anymore coffee or biscuits or sugar... I lead a lonely life tonight.

Gonna wake up around 5 or 6 and revise quickly before heading to school :/ Last exam. SO glad it's going to be over in... 8 hours..

How long is the exam?

Reply 983

Original post by CollateralElement

Might go to sleep in about 5 or 10 minutes. I'm already so tired and starving. Can't have anymore coffee or biscuits or sugar... I lead a lonely life tonight.

Gonna wake up around 5 or 6 and revise quickly before heading to school :/ Last exam. SO glad it's going to be over in... 8 hours..

How long is the exam?

1 hour 15 mins. I;ll probably learn this paper go pray and then hit the decks til about 4ish 5ish and work from then. Do you understand everything more or less now or is the kidney still a bitch?

Reply 984

kishenp

this is majorly random
but does any of you lot do maths
and have or no of the unofficial mark scheme for c4 edexcel today ?
Thanks

Reply 985

Neodamura

Original post by CollateralElement

Might go to sleep in about 5 or 10 minutes. I'm already so tired and starving. Can't have anymore coffee or biscuits or sugar... I lead a lonely life tonight.

Gonna wake up around 5 or 6 and revise quickly before heading to school :/ Last exam. SO glad it's going to be over in... 8 hours..

How long is the exam?

Me too, but i am going through this thread again to see if i missed anything out. Thanks for the help everyone. Sweet Dreams, Good Game.

Reply 986

Original post by Neodamura

Me too, but i am going through this thread again to see if i missed anything out. Thanks for the help everyone. Sweet Dreams, Good Game.

good luck bro!

Reply 987

Original post by atman7

1 hour 15 mins. I;ll probably learn this paper go pray and then hit the decks til about 4ish 5ish and work from then. Do you understand everything more or less now or is the kidney still a bitch?

Ah. Kidney is still bad but I feel better about tackling it. It's like - I've received ninja training.

I like the testing for pregnancy/steroids. I like ADH and Kidney failure... just not the kidney itself.

And yes. Praying. Praying is good. I've been doing a lot of that lately this week. Pretty much consisting of promises, vows, sorry..., yelling about time etc and asking for help.

I need a miracle anyway. That target of an A seems surreal now.

Reply 988

someone uploaded this have a glance at it

www.thestudentroom.co.uk/attachment.php?attachmentid=159022&d=1340291945

Reply 989

Original post by Neodamura

Me too, but i am going through this thread again to see if i missed anything out. Thanks for the help everyone. Sweet Dreams, Good Game.

You too!

You're gonna do great.

Reply 990

kishenp

oh yeh
the kidney stuff hasnt actually came up for properly
like dialysis etc
will that come up
one thing i hate !!! :frown:

any help on dialysis ?

Reply 991

Original post by atman7

someone uploaded this have a glance at it

www.thestudentroom.co.uk/attachment.php?attachmentid=159022&d=1340291945

Oh my goodness... This is both ridiculous and helpful.

Reply 992

Original post by CollateralElement

Ah. Kidney is still bad but I feel better about tackling it. It's like - I've received ninja training.

I like the testing for pregnancy/steroids. I like ADH and Kidney failure... just not the kidney itself.

And yes. Praying. Praying is good. I've been doing a lot of that lately this week. Pretty much consisting of promises, vows, sorry..., yelling about time etc and asking for help.

I need a miracle anyway. That target of an A seems surreal now.

You'll be okay man :biggrin:

lets hope for a photosynthesis and respiration paper to our liking! Steroids may come up pregnancy testing not so much I dont think!

Haemodialysis is when you attach dialysis machine to the vein and use an anticogulant to prevent blood from clotting. And it results in removal of waste products from the blood. has to be done frequnetly 7 times a week i think?

Reply 993