Question about the mass gain of Potato Cells

[Jayward]

I thought sucrose can't pass through the membrane by simple diffusion because of its large size.

the mass gain is not due to the acquisition of sucrose via simple diffusion. It is caused by the passive osmotic movement of water from a region of low solute to high solute concentration

[alondouek]

No no, I know what it means. But like. M. Why not another letter?

M for Molar! Simple as that.

I mean, if ever there is a problem with unit abbreviations, it's pounds = lbs. Seriously, America?

the mass gain is not due to the acquisition of sucrose via simple diffusion. It is caused by the passive osmotic movement of water from a region of low solute to high solute concentration

^This. The only way sucrose can travel across a plasma membrane is through facilitated diffusion (i.e. with the help of carrier proteins). To reiterate Jayward, mass change is as a result of osmosis either in or out of the cell depending on the tonicity of the environment it is in.

[xlaiyn]

M for Molar! Simple as that.

I mean, if ever there is a problem with unit abbreviations, it's pounds = lbs. Seriously, America?

That made me laugh.

No no, but why Molar? Why do they name these things with words like that? Why words? Why English? Communication and engrishhhhh.

[alondouek]

That made me laugh.

No no, but why Molar? Why do they name these things with words like that? Why words? Why English? Communication and engrishhhhh.

Googled it for you:

"The unit "mole" was introduced into chemistry around 1900 by Ostwald, and he originally defined this unit in terms of gram. Gram is a unit of mass; but what is the mole a unit of? Ostwald did not say; however, several years later, he did make it clear that the concept of mole should be linked to the ideal gas.

"...the molecular weight of a substance, expressed in grams, shall henceforth be called mole [. . . das in Grammen augedruckte [. . .] Molekulargewicht eines Stoffes soll fortan ein Mol heissen]".

Basically a German chemist decided it would be a good idea, but didn't initially explain it to anyone for the lulz.

[Jayward]

That made me laugh.

No no, but why Molar? Why do they name these things with words like that? Why words? Why English? Communication and engrishhhhh.

^i have moments like this all the time. What deranged drunkard came up with the word 'strudel'?! what were they on? Or even 'pickle' for that matter. they sound so odd.

[xlaiyn]

It irritates me to no end. Like, why?! Fuckennnnnn.

[AbominableMowman]

So I have a question about the potato prac..
The various solutions in which the potato cylinders were placed were made up of two substances: water and sucrose of varying concentrations. Of the two, which passed into and out of the potato cells? Explain your answer.
Is it always water that passes in and out of the cell? Does diffusion occur with the sucrose molecules?

[Yacoubb]

So I have a question about the potato prac..
The various solutions in which the potato cylinders were placed were made up of two substances: water and sucrose of varying concentrations. Of the two, which passed into and out of the potato cells? Explain your answer.
Is it always water that passes in and out of the cell? Does diffusion occur with the sucrose molecules?

(a) Water molecules - sucrose is actually lipophobic (diffusion occurs across the pores of the phospholipid bi-layer, and sucrose solutions cannot diffuse across). Water molecules are small enough to fit in the pores of the phospholipid bi-layer and have an overall neutral charge, enabling them to cross the membrane.

(b) Diffusion does not occur with sucrose molecules - sucrose molecules will travel through facilitated diffusion across the protein molecule after undergoing a conformational change when a protein carrier attaches to the solute, and will travel into/out of cell via the protein channel.

I hope that sort of answers your question