IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: winnie101 on May 11, 2010, 08:18:59 pm

Title: AS bio
Post by: winnie101 on May 11, 2010, 08:18:59 pm

could someone plz explain to me what is oedema and competitive and non-competitive inhibitors?
Thanks

Title: Re: AS bio
Post by: cashem'up on May 11, 2010, 08:30:26 pm

oedema occurrs when the body is lacking proteins or deficient and thus less plasma proteins are formed raising the water potential of the blood thus more water diffuses into tissue fluid which swells  up and knwn as oedema

Title: Re: AS bio
Post by: winnie101 on May 11, 2010, 08:59:40 pm

i thought it was when the lymph is unable to take the proteins through its large gaps, therefore a build up of protein in the tissue fluid, which lowers the water potential and causes water to move by osmosis into the tissue fluid. part of ur ans is similar but u r saying tht there is a lack of protein. this is wht my book says, i dont get it, "if the protein conc. and rate of loss from plasma r not in balance with the conc, and rate of loss from tissue fluid, there can be a build up tissue fluid, called oedema."
could u help further plz
Thanks

Title: Re: AS bio
Post by: cashem'up on May 12, 2010, 05:26:23 am

Quote from: winnie101 on May 11, 2010, 08:59:40 pm

i thought it was when the lymph is unable to take the proteins through its large gaps, therefore a build up of protein in the tissue fluid, which lowers the water potential and causes water to move by osmosis into the tissue fluid. part of ur ans is similar but u r saying tht there is a lack of protein. this is wht my book says, i dont get it, "if the protein conc. and rate of loss from plasma r not in balance with the conc, and rate of loss from tissue fluid, there can be a build up tissue fluid, called oedema."
could u help further plz
Thanks

hey listen....... wat i told u earlier  was a later form of oedema called Kwashiorkor which happens to the reasons mentioned above........... however oedema is simply the swelling up or accumulation of tissue fluid which has many ways to happen like u said and like  i said as long as it results in the swelling of tissue fluid

Title: Re: AS bio
Post by: sizbeauty on May 13, 2010, 02:36:22 pm

i hav a ques,plz sm1 ans..
suggest four reasons why mammals might store lipidz in preference to carbohydrates?(oder than high calorific value and high metabolic water produced,dese two were already givvn in ques)

Title: Re: AS bio
Post by: cashem'up on May 13, 2010, 02:50:50 pm

lipids have more C-H bonds and thus more energy released upond respiration...... They are insoluble and compact and thus more can be stored....they do not affect the conc  gradient of cells as they are insoluble however some carbo's like glucose may affect the water potential
 ;D ;D ;D

Title: Re: AS bio
Post by: sizbeauty on May 13, 2010, 03:27:55 pm

thx alot...best of luck fr tmrw  :)

Title: Re: AS bio
Post by: sizbeauty on May 13, 2010, 03:30:06 pm

@ ima:see if u can ans dese ques,ll b really grateful to u.

suggest the significance of the 5' and 3' endz of the two strandz of the DNA double helix?
suggest briefly why it is thought tht the arrangement of the bases in the nucleic acidz is in the form of a 'triplet code'?(3 markz)
suggest why DNA synthesis takes place in opposite directions on the two separated strandz of the double helix?

plz clear ma confusionz.