Potato

[Primarygun]

Fancy there has a beaker with water, a potato without skin is put at the central of the beaker.

There is a cavity on the potato,about 7 cm.

The cavity is contained with a sucrose solution.

The water potential outside is higher than that of the sucrose solution.

The cell membrane is a differentially permeable membrane.

After ten minutes, if we cut a small cell from the cavity region and observe under microscope.

What's the appearence of the cell?

Flaccid, plasmolysis or turgid?

[ed84c]

flaccid i doubt the water could osmose that far in 10 mins.

[YT2095]

and the outside Turgid (full of water).

[Primarygun]

isn't there a net movement of water into the cell and thus into the cytoplasm?

[ed84c]

net movement in (outer cells) net movement out (inner cells)

[Primarygun]

Isn't the water potential inside increased since the solute concentration is lowered?

[Sorcerer]

turgid, the sucrose solution will be drawing water towards itself, provided its osmolarity is greater than that of the potatoes cytoplasm. Thus it will create a water potential which is in the direction of the water to the sucrose. The outside cells will be turgid as the water is drawn into them, the inside cells will be flaccid as the water has be drawn out of them.

 

Note: drawing water out of the inside cells causes a chain of effect as water is then drawn from the next layer of cells to find equilibrim, this chain is continued till the water is reached, here the net flow will be greatest as the osmolarity difference is also greatest, so the outside cells will be turgid for sure, the inside ones will be flaccid untill the sucrose/cytoplasm concentrations are at equilibrium.

[Primarygun]

Cell X is turgid?

[Sorcerer]

I would say so. Thers a water potential set up from outside to inside, the outer cells are like the tap, and the inner ones like the end of the hose, pressure is greatest at the tap and tapers off as it extends along the chain.

[Primarygun]

thank you