My question is, what tells me that Histidine is positively charged just by looking at the structure:
I thought H3
would make it neutral, or there is a positive charge on the ring?
The problem is, I'm drawing a dipeptide structure of Hys + Gly and I have to tell the structure's charge in pH 5.5 and pH 7.5 . I have no idea how or why either! Completely lost... Help.
At least tell me I drew it right. They're asking for it very simple, this is not worth anything I'm only studying for an exam, so I wasn't expecting to show this drawing to anyone. I'm sorry. Thank you!