osmosis. (1 Viewer)

[jannny]

Alright so osmosis the movement of water from a high conc to a lower concentration through a semi permeable gradient.

In roots, water enter the xylem tubes through osmosis as the roots have dissolved substances, therefore the soil has a higher concentration.

So, yea water moves from High to Low (concentration)

When sugar is loaded to the phloem cells through active transport, water enters by osmosis to phloem cells as phloem cells have higher concentration.

So does that mean water moved from a Low to High (concentration) ?

Saltwater fish constantly lose water to their salty environment.

Does that mean water moves from a Low to High (concentration)?

Im just quite confused, Help appreciated cheers

 

[zingerburger]

Just a few quick corrections first:

• Water moves through a semi-permeable membrane, not gradient.
• "Dissolved substances" might not suffice in an HSC answer. You should write "dissolved ions" or something like that.

Water does move from high to low concentration in phloem. Sugar is transported into phloem, and water moves in from surrounding cells, as there is now a high concentration of solutes (low concentration of water) in the phloem tubes.

Water loss occurs in salt-water fish because again, there is a higher concentration of solutes outside the fish's body. Water moves out to try and dissolve the solute and even the concentration gradient.

Basically, water follows the concentration gradient of solutes, moving from a low concentration of solutes to a high concentration so as to even the concentration gradient of solutes across a membrane.

 

[tennille]

Osmosis is the movement of water from high concentration to low concentration. This is the "concentration" of water, not the concentration of solute. As mentioned by the above member, if there is a larger amount of solute in water, then the water is in low concentration (ie. there is a lower concentration of water in salt water than there is in fresh water). This is a bit of a dodgy explanation, but just keep in mind that they are not referring to the concentration of solute but rather the concentration of water, which is decreased when the amount of solute is increased.

 

[Buiboi]

what they said

 

[jannny]

thanks guys, it is the solutes after all =]