Hey! Sign in to get help with your study questionsNew here? Join for free to post

Biology A2 homeostasis

    • Thread Starter

    Can someone please help me with these questions Name:  ImageUploadedByStudent Room1475349030.024456.jpg
Views: 37
Size:  150.3 KBName:  ImageUploadedByStudent Room1475349039.888597.jpg
Views: 39
Size:  148.3 KB

    Posted from TSR Mobile

    The principle of dialysis (used effectively as a substitute for the kidneys, which have failed) is to filter out harmful substances (excess water, urea [end-product of protein breakdown (effectively of amino acid breakdown)], excess electrolytes, creattinine, uric acid [end product of DNA and RNA breakdown] out of the blood compartment into the "urine" (in this case, virtual) compartment. This requires the passage of these substances through a membrane that allows them to pass through.(I) Suitable as it is semi-permeable = allows small molecules like urea and Na+, Cl- etc through.Allows excess water to go through by osmosisIt has a good blood supply which means the process of "cleaning" is efficient.(ii) The volume of liquid in haemodialysis is larger = allows quicker filtration(iii) Dialysis fluid could be made to have lower water potential by dissolving extra solutes in it = more water filtered into it by osmosis(iv) Greater distance for substances to travel by diffusionperitoneal membrane may not be semi-permeable any longer = osmosis less efficient
Write a reply… Reply
Submit reply


Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: October 16, 2016
TSR Support Team
How many mugs of tea do you drink a day?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.