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osmosis help

hi ive been trying to learn unit 3 biology by myself and I understand osmosis upto the point where it mentions dilute solution - I don't get what that means, ive looked it up too and how to know hen water moves in or out of a cell? please could someone help me ive used many books and youtube but I'm still stuck- the cgp mentions if a cell lacks water, the solution inside becomes concentrated so the solution outside is more dilute so water moves into cell by osmosis... but I don't get what the hell that means lol
You understand that osmosis is the movement of water from an area of high concentration to low concentration, yes? It's like if you separate a ball pit with a thick slate down the middle and stack all the balls in one half and then remove the slate, the balls will move from the full half to the empty half.

When we're talking about solutions and not just water, concentrated means there is less water per solute. Since the water outside the cell is dilute and the water inside is concentrated, it means the higher concentration of water - not solute is outside, as there is more water per solute in the dilute solution. So the water moves into the cell to balance it out.
(edited 6 years ago)
I can try;
so, lets say there's a solution, containing any solute, e.g Sodium for example. The less water there is, the more concentrated this solution is, because there is little water and comparatively lots of solute.
the more water there is, the more dilute this solution is, because there is lots of water and comparatively little solute.

So if there's a concentrated solution, water potential is low because there is comparatively lots of solute to water, so water moves in by osmosis,
If the solution is dilute, the opposite happens.

Obviously, this is dependant of the water potential originally though.

If I'm wrong someone please correct me, I don't think I am though.
Reply 3
Avatar for Maivnek
Maivnek
15
When talking about concentration we're referring to the concentration of solute (e.g. salt) in the solution.

Cells have a semi-permeable membrane that allows for water (but not the solute solute) to pass through.

If one side of the membrane has a higher concentration of e.g. salt, water will move from the other side (with low concentration of salt) to the side with high concentration of salt, thus balancing the concentration on both sides.

This is essentially the process of osmosis. Osmosis ensures equal concentrations of solute on two sides of a membrane.

When there is equal concentration on both sides, water will still flow both ways, but flow equally since equilibrium is reached.

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Reply 4
Avatar for usernamenew
usernamenew
OP
9
Original post by Maivnek
When talking about concentration we're referring to the concentration of solute (e.g. salt) in the solution.

Cells have a semi-permeable membrane that allows for water (but not the solute solute) to pass through.

If one side of the membrane has a higher concentration of e.g. salt, water will move from the other side (with low concentration of salt) to the side with high concentration of salt, thus balancing the concentration on both sides.

This is essentially the process of osmosis. Osmosis ensures equal concentrations of solute on two sides of a membrane.

When there is equal concentration on both sides, water will still flow both ways, but flow equally since equilibrium is reached.

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thank you so much, so basically if theres a higher concentration of the solute on one side, the other side tries to add more of the solute to the higher concentration?
Reply 5
Avatar for usernamenew
usernamenew
OP
9
Original post by hamzakalinle
I can try;
so, lets say there's a solution, containing any solute, e.g Sodium for example. The less water there is, the more concentrated this solution is, because there is little water and comparatively lots of solute.
the more water there is, the more dilute this solution is, because there is lots of water and comparatively little solute.

So if there's a concentrated solution, water potential is low because there is comparatively lots of solute to water, so water moves in by osmosis,
If the solution is dilute, the opposite happens.

Obviously, this is dependant of the water potential originally though.

If I'm wrong someone please correct me, I don't think I am though.


thank you, that helped!
Reply 6
Avatar for usernamenew
usernamenew
OP
9
Original post by orderofthelotus
You understand that osmosis is the movement of water from an area of high concentration to low concentration, yes? It's like if you separate a ball pit with a thick slate down the middle and stack all the balls in one half and then remove the slate, the balls will move from the full half to the empty half.

When we're talking about solutions and not just water, concentrated means there is less water per solute. Since the water outside the cell is dilute and the water inside is concentrated, it means the higher concentration of water - not solute is outside, as there is more water per solute in the dilute solution. So the water moves into the cell to balance it out.


thank you so much, but i got a little confused here sorry, so concentrated means there is more of the solute , and if the water outside the cell is dilute- that means higher concentration of water?
Reply 7
Avatar for Maivnek
Maivnek
15
Original post by usernamenew
thank you so much, so basically if theres a higher concentration of the solute on one side, the other side tries to add more of the solute to the higher concentration?


No, that's the thing. The membrane is only permeable to water (among some other molecules like CO2), the salt cannot freely move like the water. So osmosis is the process of water moving between two sides of a membrane.

If there's more solute(e.g. salt) molecules in relation to water molecules in one side, then water moves from low salt concentration to high, in order to have an equal solute to water ratio on both sides.

Edit: I see now, you probably meant to say water instead of solute the second time. In that case, you had the right idea.:top:

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(edited 6 years ago)
Reply 8
Avatar for usernamenew
usernamenew
OP
9
Original post by Maivnek
No, that's the thing. The membrane is only permeable to water (among some other molecules like CO2), the salt cannot freely move like the water. So osmosis is the process of water moving between two sides of a membrane.

If there's more solute(e.g. salt) molecules in relation to water molecules in one side, then water moves from low salt concentration to high, in order to have an equal solute to water ratio on both sides.

Edit: I see now, you probably meant to say water instead of solute the second time. In that case, you had the right idea.:top:

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thank you so much that makes sense now!
Original post by usernamenew
thank you so much, but i got a little confused here sorry, so concentrated means there is more of the solute , and if the water outside the cell is dilute- that means higher concentration of water?


Generally speaking, when we say something is very concentrated, we mean that there is very little water per solute. When you drink orange squash or a drink like Ribena that you didn't put enough water in, it tastes very strong - it is concentrated.

However, we can also talk about the concentration of water in the same way. When the concentration of water is high, we mean there is more water for each molecule of solute. It is the same as saying the concentration of solute is low. Capiche?

So since the water outside the cell is dilute, it means there is more water per molecule of solute than inside the cell, which is concentrated. So to balance out the concentration of solute on both sides of the cell's membrane, more water flows into the cell than out of it.

Make sure you don't get the concentration of water twisted with the concentration of solute!

I always did hate biology. :h:
Original post by usernamenew
thank you so much that makes sense now!


No problem :smile:

An egg can greatly represent this process when put in water. If put in 100% water, it will take in water and increase in size. If put in salt water (with higher salt concentration than that of the egg), it will excrete water and decrease in size become wrinkly.
You should check it out on youtube...

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