diffusion across membrane

[chiddler]

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Is it necessary for O2 and CO2 to pass through intercellular clefts in capillaries?

No, because they can pass any cell membrane via simple diffusion. However, these clefts are necessary to move nutrients and waste (and leukocytes, but not relevant.)

Why can O2 and CO2 move across membranes via simple diffusion? Is it because they are uncharged and nonpolar?

 

[milski]

Why can O2 and CO2 move across membranes via simple diffusion? Is it because they are uncharged and nonpolar?

Yes. Non-polar and relatively small molecules will pass through a membrane.

 

[chiddler]

Yes. Non-polar and relatively small molecules will pass through a membrane.

thank you.

 

[SaintJude]

Why is this factoid important? (not being sarcastic.)

 

[MedPR]

Why is this factoid important? (not being sarcastic.)

Perhaps because O2/CO2 diffuse into blood passively. PO2 is the amount of O2 dissolved in blood (not the amount bound to Hb) and if the body was constantly having to pump O2 across membranes it would consume a lot of energy.

I don't really know why it's important, but it is good to remember that small non-polar molecules diffuse freely.

 

[milski]

Why is this factoid important? (not being sarcastic.)

You could predict if other similar molecules can get through it - like NH3 or CCl4...