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How does temperature affect the rate of diffusion?

Asked by jane_smith | Jan 1, 2003 | AS Level > Biology > Coursework
jane_smith
jane_smith asks:

How does temperature affect the rate of diffusion of beetroot pigment when pieces of fresh beetroot are placed in water? I know that pigment will be released more quickly when the temperature is higher, but can you explain why this is? What scientific background material should I be including in the introduction to an assessed practical investigation on this subject?

etutor answers:
There are two factors to consider. Firstly, diffusion is the movement of molecules, and this is increased with increasing temperature - so diffucsion speeds up as temperature increases. In living cells, however, temperatures above about 40 degrees will damage the protein in the cell membrane, and this will allow pigment to leak out quicker. So, you would expect diffusion to increase at a steady rate up to around 40 or 50 degrees, and thereafter increase at a faster rate as it is easier for the pigment to escape from the cell.
Background material you should include would be a scientific explanation of diffusion, an account of the structure of the cell membrane and particle theory (increasing temp. speeds up particles).

11 student responses

diane
diane
could you please tell me what the limitations of an experiment which investigated the effect of pH on beetroot membranes would be when the size of beetroot is kept the same the pH is varied the temperatue is kept the same the same amount of acid and alkali is used and also what further experiments would be useful please could you reply a.s.a.p thankyou
responded Feb 21, 2003 6:40:03 PM GMT
jack
jack
There are two factors to consider. Firstly, diffusion is the movement of molecules, and this is increased with increasing temperature - so diffucsion speeds up as temperature increases. In living cells, however, temperatures above about 40 degrees will damage the protein in the cell membrane, and this will allow pigment to leak out quicker. So, you would expect diffusion to increase at a steady rate up to around 40 or 50 degrees, and thereafter increase at a faster rate as it is easier for the pigment to escape from the cell. so what grade is this
responded Feb 26, 2003 11:40:01 PM GMT
john smith
john smith
i need help. the essay above by jane is crap.
responded Feb 26, 2003 11:41:49 PM GMT
jon
jon
concise but useful
responded Nov 6, 2003 8:48:47 PM GMT
SofaStar
SofaStar
I also read that after about 70 degrees the diffusion slows down because there concentration gradient is very similar in the beetroot tissue and in the surrounding water.
responded Nov 24, 2003 5:26:35 PM GMT
Jenny
Jenny
I am doing this c/w on beetroot and pigment (As level) and i was wondering what were the relevent to put into to the evaluation and the part before this.analysis of results. and is 7 a good mark for the first part of the c/w? thank u
responded Dec 2, 2003 1:16:42 PM GMT
SofaStar
SofaStar
Jenny-if your coursework is marked the same way mine is then 7 is good because each part is marked out of 8(apart from the evaluation which is out of 6)
responded Dec 8, 2003 8:36:05 PM GMT
Nick Sandeman
Nick Sandeman
the pigment in beetroot is too large to diffuse through the membrane, and there is no reason for the cell to have specific transport proteins since its role is intracellular. Instead the release of pigment with increasing temperature is due to the increasing thermolability of the membrane. There will be some influence from the denaturation of the membrane proteins. Osmosis into the cells will increase the pressure which will burst the membrane. This will happen faster at higher temperature since the membrane is more labile. The cell wall is meant to protect against this occurrence, but the hydrogen bonds between the cellulose strands break as the temperature rises, and the integrity of the cell wall is compromised.
responded Dec 19, 2003 11:38:12 AM GMT
lisa
lisa
i need help with kinetic theory to help to write my conclusion. please can u help me at all im doning temperature on the rate of diffusion on anthocyanin pigments
responded Feb 9, 2004 11:29:31 PM GMT
charlotte
charlotte
how comes at 0 oC the rate of diffusion is as fast as it was at 80 oC please help!
responded Nov 30, 2004 9:33:08 PM GMT
Andy
Andy
You are amazing , saved my life with that coursework help!!!!!!!!!!!!
responded Dec 11, 2004 10:55:54 AM GMT
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