[smghz]

I was perplexed by different structures of amino acids online. For example, here is what I got from Khan Academy for leucine:


But another more common structure is this:


Why the difference in the positioning of the H and carboxylic group? thanks.

[Enthalpy]

Do you believe these two representations differ? (Apart from the ionization)

Molecules can differ by the relative positions of sub-groups, but in such flat representations, this information is missing.

[smghz]

So helpful, thanks!