Biology series [Unit : Cells, Problem 6]
Level
2
The oxygen and carbon dioxide crosses the plasma membrane by the process of -
Random diffusion
Passive diffusion
Active diffusion
Facilitated diffusion
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Passive diffusion follows a concentration gradient , which relates to the transport of molecules from a location of higher concentration to a site of lower concentration without using chemical energy according to Fick’s law of diffusion .
The transport of a substance is therefore influenced by physical–chemical properties such as the concentration gradient , the membrane surface area , or the substance‐specific diffusion coefficient .
The lipophilicity of the drug plays a key role in these processes as the transport takes places between the hydrophilic area on the membrane surface , the lipophilic inner part of the membrane , and the again comparably hydrophilic cytosol inside the cell .