structural formula questions

[thewax]

In structural formulas like -COOH and -CH2OH why is the COOH not written with a subcript of 2 instead of the second O and in CH2OH why is there the subscript 2 instead of writing the two H's out and why isn't it a H3 and why was the last H written out? In structural formulas, why are some subscripts written out and some subscripts written? Would it be okay to use them interchangeably (like CO2H and CH3O)?

[MichaelXY]

Biology peeps like to know what is dangling on the ends. I think Chemist don't care so much

[MrMistery]

It all depends on what atoms are important, so to speak. In your examples, the hydrogens don't really matter much, they are only there to fill the empty space in carbon orbitals. the carboxylate group, however, is important. and it is important to write is like that because of how it reacts. CO2H might be acceptable if you really really stretch it. However, CH3O is never never acceptable, because one of those three hydrogens is bound to an oxygen atom and the other two are bound to the carbon atom.
If you really want to understand this stuff you should pick up an organic chemistry book.