Why is O2 and CO2 considered hydrophobic gases?

[Coolgalbornin03Lo]

They apparently can pass through membrane because they are hydrophobic molecules. But in Chem i know that these two are polar, meaning they’d be hydrophilic......does that mean hydrophilic small molecules can pass through the membrane? Somebody plz explain.

[Erutepa]

They apparently can pass through membrane because they are hydrophobic molecules. But in Chem i know that these two are polar, meaning they’d be hydrophilic......does that mean hydrophilic small molecules can pass through the membrane? Somebody plz explain.

Both oxygen and Carbon dioxide are indeed hydrophobic/non-polar molecules and - since they are relatively small - can pass through the plasma membrane.
That being said very small hydrophilic molecules like water can also pass through the plasma membrane.

[Othello]

Oxygen gas, O2, is not polar as the difference in electronegativity is zero (because the two oxygen atoms have the same electronegativity). While CO2 has polar bonds (as the difference in electronegativity between carbon and oxygen is not zero), with oxygen “pulling” on the bonded electrons between itself and carbon, CO2’s linear shape means that the polar bonds cancel each other out, as they are on opposite ends of the carbon atom. Thus, neither of them are polar and are therefore hydrophobic.

[Erutepa]

Oxygen gas, O2, is not polar as the difference in electronegativity is zero (because the two oxygen atoms have the same electronegativity). While CO2 has polar bonds (as the difference in electronegativity between carbon and oxygen is not zero), with oxygen “pulling” on the bonded electrons between itself and carbon, CO2’s linear shape means that the polar bonds cancel each other out, as they are on opposite ends of the carbon atom. Thus, neither of them are polar and are therefore hydrophobic.

This is a fantastic explanation of why oxygen and carbondioxide gas are non-polar, however to those reading this, this level of knowledge is not needed for 3/4 biology so do not fear if you don't understand it (this stuff is more chemisty content) . It is sufficint to just know that oxygen and carbondioxide gas are non-polar.

Also welcome to the forums Othello!

[Coolgalbornin03Lo]

This is a fantastic explanation of why oxygen and carbondioxide gas are non-polar, however to those reading this, this level of knowledge is not needed for 3/4 biology so do not fear if you don't understand it (this stuff is more chemisty 3/4 content) . It is sufficint to just know that oxygen and carbondioxide gas are non-polar.

Also welcome to the forums Othello!

I just finished Chem 1/2 and I understand it perfectly.....thanks othello!