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Cell Lysis?
By danson2080 on 27/04/2011
Are there any cellular biology or physiology people who can help with this?
We have a project about cell permeability and osmosis and what not. One of the points is about cell lysis in a hypotonic solution, which I understand. If the cell has a semi-permeable membrane and the concentration of particles is greater inside the cell than in the outside solution, water floods in the cell and it bursts.
With a hypertonic solution, the opposite happens. The cell has a lower concentration of particles that can't cross the membrane, so the cell excretes its water, which also kills it.
My issue is figuring out whether or not this is always the case. Could you have a hypertonic solution, where the concentrated particles are small enough to pass into the cell and cause it to lyse that way? I feel like it would work in theory but I'm not sure if there are any solutions that have particles small enough to pass through a cell membrane but at the same time is concentrated enough to actually cause lysis.
We have a project about cell permeability and osmosis and what not. One of the points is about cell lysis in a hypotonic solution, which I understand. If the cell has a semi-permeable membrane and the concentration of particles is greater inside the cell than in the outside solution, water floods in the cell and it bursts.
With a hypertonic solution, the opposite happens. The cell has a lower concentration of particles that can't cross the membrane, so the cell excretes its water, which also kills it.
My issue is figuring out whether or not this is always the case. Could you have a hypertonic solution, where the concentrated particles are small enough to pass into the cell and cause it to lyse that way? I feel like it would work in theory but I'm not sure if there are any solutions that have particles small enough to pass through a cell membrane but at the same time is concentrated enough to actually cause lysis.
By Zooby69 on 27/04/2011
| QUOTE |
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I do a biomedical degree but.. im kinda shit at it. Is this for Biology year 12? Anyway, In the membrane you have protein channels, these stop most substances from going through the membrane but some substances (maltose/glucose) could still manage to diffuse across the membrane and boy-cot the protein channels. These particles can diffuse across the membrane but not all of them can because of their size and the protein channels, therefore osmosis/lysis cannot completely occur, it is occuring somewhat, but not completely. I haven't studied osmosis in a few years so dont hold me to this. I still know the definition though. I will go and find my molecular biology book and update this post. For now use what I said as a guide, if it is any help at all. |
After re-reading your post I've noticed a few things, through osmosis (the net diffusion of water from a high concentration to a low concentration across a membrane, down a gradient) a cell does not nessicarly burst/excrete all liquids, this is a severe case and generally does not happen via a semi-permeable membrane, the goal of osmosis is to make an even distribution of concentration, so you might want to look over the whole topic again. Lysis is when the cell bursts/shrinks, osmosis is when the concentration changes but the cell remains intact and can function. Do not think they are the same.
Also - there are two types of "lyse"; Cytolysis and Plasmolysis,
Cytolysis is when the cell has a lower salt concentration than that of the outside environment (hypotonic) so salt floods in and is not limited, this is also known as excessive osmosis, and the cell bursts because of the cell membrane not being able to expand (unlike a cell wall in plants)
Plasmolysis is when the cell has a higher salt concentration than that of the outside environment (hypertonic) and salt rushes out of the sell and is not limited, again excessive osmosis, and the cell shrinks and will eventually die is the cell membrane does not stop the flow of water/salt out of the cell.
As for the question; The lipid part of the membrane is what controls the movement of ions or polar compounds across the membrane. The protein layer allows for non-polar compounds to cross (generally larger molecules).
For the cell to Plasmolyse, which is what happens in the hypertonic solution you are talking about, and small particles would have to leave the cell for this lysis to occur. This could work in theory and somewhat in reality but honestly osmosis would be initiated if the concentration of salt was greater inside the cell, so you would have to put loads of water and salt into the cell, or remove all salt/water from the outside environment so the salt from inside the cell will diffuse across the cell membrane into the outside environment and only if plasmolysis occurs will the cell actually lyse/die.
I hope that made sense, but remeber, in science there is always outliers and variance.
Pro tip; Ask your teacher, they are there to help, even if it's an assignment.
By Raging Mage2 on 27/04/2011
| QUOTE: Zooby69 @ April 27, 2011 03:06 am) | ||
After re-reading your post I've noticed a few things, through osmosis (the net diffusion of water from a high concentration to a low concentration across a membrane, down a gradient) a cell does not nessicarly burst/excrete all liquids, this is a severe case and generally does not happen via a semi-permeable membrane, the goal of osmosis is to make an even distribution of concentration, so you might want to look over the whole topic again. Lysis is when the cell bursts/shrinks, osmosis is when the concentration changes but the cell remains intact and can function. Do not think they are the same. Also - there are two types of "lyse"; Cytolysis and Plasmolysis, Cytolysis is when the cell has a lower salt concentration than that of the outside environment (hypotonic) so salt floods in and is not limited, this is also known as excessive osmosis, and the cell bursts because of the cell membrane not being able to expand (unlike a cell wall in plants) Plasmolysis is when the cell has a higher salt concentration than that of the outside environment (hypertonic) and salt rushes out of the sell and is not limited, again excessive osmosis, and the cell shrinks and will eventually die is the cell membrane does not stop the flow of water/salt out of the cell. As for the question; The lipid part of the membrane is what controls the movement of ions or polar compounds across the membrane. The protein layer allows for non-polar compounds to cross (generally larger molecules). For the cell to Plasmolyse, which is what happens in the hypertonic solution you are talking about, and small particles would have to leave the cell for this lysis to occur. This could work in theory and somewhat in reality but honestly osmosis would be initiated if the concentration of salt was greater inside the cell, so you would have to put loads of water and salt into the cell, or remove all salt/water from the outside environment so the salt from inside the cell will diffuse across the cell membrane into the outside environment and only if plasmolysis occurs will the cell actually lyse/die. I hope that made sense, but remeber, in science there is always outliers and variance. Pro tip; Ask your teacher, they are there to help, even if it's an assignment. |
nurd
By Elyxiatic on 28/04/2011
| QUOTE: Zooby69 @ April 27, 2011 06:06 pm) | ||
After re-reading your post I've noticed a few things, through osmosis (the net diffusion of water from a high concentration to a low concentration across a membrane, down a gradient) a cell does not nessicarly burst/excrete all liquids, this is a severe case and generally does not happen via a semi-permeable membrane, the goal of osmosis is to make an even distribution of concentration, so you might want to look over the whole topic again. Lysis is when the cell bursts/shrinks, osmosis is when the concentration changes but the cell remains intact and can function. Do not think they are the same. Also - there are two types of "lyse"; Cytolysis and Plasmolysis, Cytolysis is when the cell has a lower salt concentration than that of the outside environment (hypotonic) so salt floods in and is not limited, this is also known as excessive osmosis, and the cell bursts because of the cell membrane not being able to expand (unlike a cell wall in plants) Plasmolysis is when the cell has a higher salt concentration than that of the outside environment (hypertonic) and salt rushes out of the sell and is not limited, again excessive osmosis, and the cell shrinks and will eventually die is the cell membrane does not stop the flow of water/salt out of the cell. As for the question; The lipid part of the membrane is what controls the movement of ions or polar compounds across the membrane. The protein layer allows for non-polar compounds to cross (generally larger molecules). For the cell to Plasmolyse, which is what happens in the hypertonic solution you are talking about, and small particles would have to leave the cell for this lysis to occur. This could work in theory and somewhat in reality but honestly osmosis would be initiated if the concentration of salt was greater inside the cell, so you would have to put loads of water and salt into the cell, or remove all salt/water from the outside environment so the salt from inside the cell will diffuse across the cell membrane into the outside environment and only if plasmolysis occurs will the cell actually lyse/die. I hope that made sense, but remeber, in science there is always outliers and variance. Pro tip; Ask your teacher, they are there to help, even if it's an assignment. |
Dude.
By Zooby69 on 28/04/2011
Yes, now you realise I'm not a complete and utter moron hahaha.
By James on 28/04/2011
umm im 14 how old should i be before i even know what this shit is? :L
By Armybuilder1 on 28/04/2011
James its a-level for you.
By James on 28/04/2011
Oh okay well have fun learning that tehe
By Zooby69 on 29/04/2011
| QUOTE: James @ April 28, 2011 10:51 am) |
| umm im 14 how old should i be before i even know what this shit is? :L |
Its like 16-18.
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