mechanisms of membrane transport

[Tye707]

so a queston on my reveiw sheet asks
describe the mechanisms of membrane transport.

my answer: diffusion:passive movement of molecules, high consentate to low consentrate
osmosis:a low solute cosentration to high solute consentration
carrier transport: protein with cell membrane
bulk transport: substense intake

are my answers correct to the question? i dont understand the question

[mith]

they probably want you to describe carrier transport in more detail, including something about conformational changes.

[sapphirearth]

your answers are correct but for osmosis my teacher said a better way to put it is:
osmosis: the movement of free water molecules from a region of high free water molecules to a region of low free water molecules.

endocytosis/exocytosis -movement of large molecule into and out of the cell respectively via invagination (or folding) of the cell membrane. The memebrane forms vesicles around the large molecule.

active transport- can be in either protein channels or carrier proteins but go from low to high concentration and energy is expended.

channel proteins-generally transport ions (charged particles) through the cell membrane

for diffusion there is also lots of ways , you may like to elaborate like describe how lipid soluble molecules would dissolve through the lipid bilayer of the membrane. And how small molecules like urea , water and carbon dioxide sqeeze through the phospholipid heads to travel thorugh

hope this helps..
and good luck

[whawth]

Good answer but I think it is more looking for like exocytosis how a vacuole move objects in or out in the case of endocytosis

[MrMistery]

what about protein translocation?

Problem: you have a protein one side of a membrane and you want to get it on the other side. How do you do it?

[kbyars10]

I liked you example of endocytosis and exocytosis!