# Pls can someone help me with my homework!!

Found 29th Oct 2009
i will give rep to helpers but i cant find the answer anywhere!!
All to do with osmosis in the cell (biology):
In which direction across the semipermeable membrane will the water molecules move when the system reaches equilibrium?
thanks guys
left to right if i remember correctly
At equilibrium:

both ways equally
as the water potentials are the same on both sides.
chesso;6728680

At equilibrium:both ways equally as the water potentials are the same on … At equilibrium:both ways equally as the water potentials are the same on both sides.

+1 there is a net movement of particles
There will be an equal amount of both water and particles- a dynamic equilibrium is reached!

The water will move in both direction's until an equilibrium is reached meaning that there will be an even amount of water particles on each side..

Edit: are you doing A level or GCSE biology?
As I remember, if there's a state of equilibrium, there will not be any movement.
Definitely both ways.

Taken from an exam paper:

II. Suppose that you have an osmosis apparatus like the one that you used in the exercise. In one side of the apparatus, there are a 100 mL of solution composed of distilled water and iodine. In the other side, there is a 10% starch solution. The liquid levels in both sides are initially the same. Answer the following questions in complete sentences.

a. What will happen to the level of the water and iodine solution (Side A)?

b. What will happen to the level of the starch solution (Side B)?

c. In which direction across the semipermeable membrane will the water molecules move when the system reaches equilibrium?

d. What will happen to the color of the water and iodine solution? Why?

e. What will happen to the color of the starch solution? Why?

f. (Extra Credit) How many grams of starch will be present in 100 grams of the 10% starch solution?

a. The level of the water and iodine solution will fall as more water moves into the starch solution than leaves it.

b. The level of the starch solution will rise since more water molecules will enter the solution than will leave it.

c. The water will move in both directions across the membrane.

d. The color of the water and iodine solution will not change since starch cannot pass through the membrane to enter the solution.

e. The color of the starch solution will turn from clear to a blue-black as iodine molecules cross the membrane, enter the solution and complex with the starch molecules.

f. Five (5) grams of starch will be present in 100 grams of a 5% starch solution.
Spriggan;6728675

left to right if i remember correctly

Genius
keeyop;6728720

Definitely both ways.Taken from an exam paper:II. Suppose that you have … Definitely both ways.Taken from an exam paper:II. Suppose that you have an osmosis apparatus like the one that you used in the exercise. In one side of the apparatus, there are a 100 mL of solution composed of distilled water and iodine. In the other side, there is a 10% starch solution. The liquid levels in both sides are initially the same. Answer the following questions in complete sentences. a. What will happen to the level of the water and iodine solution (Side A)?b. What will happen to the level of the starch solution (Side B)?c. In which direction across the semipermeable membrane will the water molecules move when the system reaches equilibrium? d. What will happen to the color of the water and iodine solution? Why?e. What will happen to the color of the starch solution? Why?f. (Extra Credit) How many grams of starch will be present in 100 grams of the 10% starch solution? And the Answer Key:a. The level of the water and iodine solution will fall as more water moves into the starch solution than leaves it.b. The level of the starch solution will rise since more water molecules will enter the solution than will leave it.c. The water will move in both directions across the membrane.d. The color of the water and iodine solution will not change since starch cannot pass through the membrane to enter the solution.e. The color of the starch solution will turn from clear to a blue-black as iodine molecules cross the membrane, enter the solution and complex with the starch molecules.f. Five (5) grams of starch will be present in 100 grams of a 5% starch solution.

that is the worksheet im doing for a level biology!!!!! where you get the answers from..lol!
mamamia7;6728825

that is the worksheet im doing for a level biology!!!!! where you get the … that is the worksheet im doing for a level biology!!!!! where you get the answers from..lol!

The internet is a wonderful thing, It's lifted from an Arizona University biology paper.
Guyver;6728712

There will be an equal amount of both water and particles- a dynamic … There will be an equal amount of both water and particles- a dynamic equilibrium is reached!The water will move in both direction's until an equilibrium is reached meaning that there will be an even amount of water particles on each side..Edit: are you doing A level or GCSE biology?

Wot he said ^^^^^^ (well impressed guyver!).
Guyver;6728712

There will be an equal amount of both water and particles- a dynamic … There will be an equal amount of both water and particles- a dynamic equilibrium is reached!The water will move in both direction's until an equilibrium is reached meaning that there will be an even amount of water particles on each side..Edit: are you doing A level or GCSE biology?

The water molecules will move in both directions but there will be a net movement form higher ( less negative) to lower ( more negative) water potential until the equilibrium is reached.
At equilibrium the water particles will move equally in both directions as the water potentials both sides of the spm are the same.

There will not be an equal number of solute particles if there were different concentrations at the start.
deek72;6728968

Wot he said ^^^^^^ (well impressed guyver!).

Thanks :oops:

Studied A level biology
chesso;6729047

The water molecules will move in both directions but there will be a net … The water molecules will move in both directions but there will be a net movement form higher ( less negative) to lower ( more negative) water potential until the equilibrium is reached. At equilibrium the water particles will move equally in both directions as the water potentials both sides of the spm are the same.There will not be an equal number of solute particles if there were different concentrations at the start.

The op asked In which direction across the semipermeable membrane will the water molecules move when the system reaches equilibrium?

and I said The water will move in both direction's

and this - t equilibrium the water particles will move equally in both directions as the water potentials both sides of the spm are the same. is known as dynamic equilibrium
Guyver;6729054

Thanks :oops:Studied A level biology

what bout this one...lol

1.You have chopped some celery for dips but it has gone limp. How could you restore the crispiness? Explain how it would work? this is also on my worksheet of osmosis and diffusion.
mamamia7;6729148

what bout this one...lol1.You have chopped some celery for dips but it … what bout this one...lol1.You have chopped some celery for dips but it has gone limp. How could you restore the crispiness? Explain how it would work? this is also on my worksheet of osmosis and diffusion.

Place in water (distilled is preferable), In plants with green stems, the cell walls of the stems are relatively thin and flexible. When the cell is full of water, it presses against the cell wall and makes it more rigid. If the plant lacks sufficient water, the cells shrink, and the pressure against the cells walls is reduced. This allows the cell walls to bend, so that the stem is unable to support the leave, and the plant wilts
keeyop;6729394

Place in water, In plants with green stems, the cell walls of the stems … Place in water, In plants with green stems, the cell walls of the stems are relatively thin and flexible. When the cell is full of water, it presses against the cell wall and makes it more rigid. If the plant lacks sufficient water, the cells shrink, and the pressure against the cells walls is reduced. This allows the cell walls to bend, so that the stem is unable to support the leave, and the plant wilts

mamamia7;6729412

Its basically to do with the difference between a plant cell and a blood cell (which has no cell wall). When the cells are placed in tap water, both types would retain their original shape. When the cells are placed in a salt or starch solution, both types will shrink, although the plant cell walls will not change shape. When the cells are placed in distilled water, both types will swell. The plant cell will expand to the limits presented by the cell wall. The blood cell, having no cell wall, will swell until it bursts.
Guyver;6728712

There will be an equal amount of [B[COLOR="DarkRed"]]both water and … There will be an equal amount of [B[COLOR="DarkRed"]]both water and particles[/COLOR][/B]- a dynamic equilibrium is reached!The [COLOR="Navy"]water will move in both direction's until an equilibrium is reached [/COLOR]meaning that there will be an even amount of water particles on each side..Edit: are you doing A level or GCSE biology?

chesso;6729047

The water molecules will move in both directions but there will be a net … The water molecules will move in both directions but there will be a net movement form higher ( less negative) to lower ( more negative) water potential until the equilibrium is reached. At equilibrium the water particles will move equally in both directions as the water potentials both sides of the spm are the same.There will not be an equal number of solute particles if there were different concentrations at the start.

Guyver;6729102

The op asked In which direction across the semipermeable membrane will … The op asked In which direction across the semipermeable membrane will the water molecules move when the system reaches equilibrium?and I said The water will move in both direction'sand this - t equilibrium the water particles will move equally in both directions as the water potentials both sides of the spm are the same. is known as dynamic equilibrium

Yes, I know that you had the water movement in there.
I am pointing out to you that
[COLOR="Red"]1. your explanation including particle numbers is incorrect.[/COLOR]
2. [COLOR="navy"]your description states that there will be movement until equilibrium is reached but doesn't state that movement is in both direction when that equilibiurm is reached. [/COLOR], which, of course, is the crux of the question.

I understand dynamic equilibrium but the answer requires an explanation of it.
chesso;6729927

Yes, I know that you had the water movement in there. I am pointing out … Yes, I know that you had the water movement in there. I am pointing out to you that[COLOR="Red"]1. your explanation including particle numbers is incorrect.[/COLOR]2. [COLOR="navy"]your description states that there will be movement until equilibrium is reached but doesn't state that movement is in both direction when that equilibiurm is reached. [/COLOR], which, of course, is the crux of the question.I understand dynamic equilibrium but the answer requires an explanation of it.

I cba arguing with you thanks
Guyver;6734301

I cba arguing with you thanks

Hope you were a little more polite with your own Biology teacher when s/he showed you how to improve your answers.