The Student Room Group

Scroll to see replies

Original post by britash
Same.. Then again i'm a bit biased as the textbook was written by one of my old teachers. :P
Still, its what makes most sense to me.
Calling it the bible.. serious-ness O.o ?!!?
I can't stand them :tongue:


Haha, if it makes sense, you should use it.
My textbooks by someone named something Toole. :cool:
Reply 161
Whats the definitions of an antibody and an antigen.
I know one is "a y-shaped protein or glycoproteins that elicits an immune response".
But what are the *mark scheme* definitions? xx
Reply 162
Original post by AlligatorSky
Haha, if it makes sense, you should use it.
My textbooks by someone named something Toole. :cool:


Susan and Glenn Toole :smile:
Woop! Let's hope thanks to their text books we all get A's :tongue:
Original post by AlligatorSky
That was.. well, quite risky of you. :P


yeah lol, had 4 other exams so i didn't/couldn't put enough time into it and thus proceeded to do it this way and i was predicting a U and planning to resit it this june...
Reply 164
Original post by AlligatorSky
Haha, if it makes sense, you should use it.
My textbooks by someone named something Toole. :cool:


good ole glenn and susan toole :biggrin:
Original post by britash
Susan and Glenn Toole :smile:
Woop! Let's hope thanks to their text books we all get A's :tongue:


Is one of them your teacher?
I really like the book.
Reply 166
Original post by AlligatorSky
Is one of them your teacher?
I really like the book.


Ex-teacher. She retired two years ago I think...
I remember her teaching me when I was about 13-ish, so yeah XD
Reply 167
Hey
You know in unit 1 topic 2 something called microscopy on how to use a microscope? I've seen it come up in a paper, can anyone tell me what it is and maybe give me 5 steps to remember if I'm asked, say, a 5 mark question?
(edited 11 years ago)
Reply 168
Can anyone answer my question about (post #162) :smile:
Original post by britash
Can anyone answer my question about (post #162) :smile:


Antigen: a molecule that triggers an immune response

Anitbody: A protein produced by lymphocytes in response to the presence of an antigen. (specific to it)
Reply 170
Do we have to know microscopy?
Original post by Tiggy1995
Hey
You know in unit 1 topic 2 something called microscopy on how to use a microscope? I've seen it come up in a paper, can anyone tell me what it is and maybe give me 5 steps to remember if I'm asked, say, a 5 mark question?


They might ask you something like whats the difference between TEM, Light and SEM,
or whats are the advantages and limitations of them.

Advantages of TEM:
High Mag and Resolution
Short wavelength

Limitations:
Should be in vaccum, non-living specimen
A complex staining process required
Specimen should be VERY thin
Image can contain artefacts.
Reply 172
As in using a eyepiece graticule scale thing etc
Reply 173
Original post by AlligatorSky
Antigen: a molecule that triggers an immune response

Anitbody: A protein produced by lymphocytes in response to the presence of an antigen. (specific to it)


Thank-you :elmo:
Reply 174
So not on EPGUs or stage micrometer things?
Reply 175
Original post by iPthreefifthteen
For carrier protein all you need to know is:

- Different carrier proteins facilitate diffusion of different molecules
- Carrier proteins transport large molecules in and out of the cell
- Down a concentration gradient i.e. from high to low concentration
- the process starts by large molecule attaching to carrier protein
- The protein then changes shape
- Which releases molecule on opposite side of membrane
- it's a passive process - no energy is used

And for protein channels:

- Different protein channels facilitate diffusion of different charged particles
- Protein channels form pores in the membrane
- For charged particles
- Down a concentration gradient
- This is also passive

I hope I haven't missed anything important out :smile:


Thank you! That makes much more sense now
Reply 176
Original post by Tiggy1995
So not on EPGUs or stage micrometer things?


Not even heard of these. You are doing AQA right?
Original post by Tiggy1995
So not on EPGUs or stage micrometer things?


Says nothing about that in my book.
Can anyone explain 'Absorption in the small intestine' ?
Reply 179
Original post by AlligatorSky
Can anyone explain 'Absorption in the small intestine' ?


Lets look at starch.

As starch enters the small intestine it is hydrolysed by pancreatic juices from the pancreas. Its hydrolysed into maltose. The epithelial lining of the small intenstine then secretes maltase to hydrolyse maltose into x2 a-glucose molecules.

The rate of absorbtion is increased by the villi of the small intestine and by the microvilli of the epithelial cells, due to providing a large surface area.

Then we can go and explain co-transport of glucose and sodium into the bloodstream.

Sodium is actively pumped out of the epithelial cell into the bloodstram by active transport.
There is now a higher concentration of sodium in the lumen of the intestine than the epithelial cell, thus sodium is co-transported with glucose into the epithelial cell down the concetration gradient using carier proteins
Glucose then diffuses across the epithelial cell into the bloodstram by fascilitated diffusion down its concetration gradient.
(edited 11 years ago)

Latest