What charge does phosphatidonic acid have at pH 7?

Phosphatidonic acid is an important phospholipid that consists of a glycerol backbone, two fatty acid tails, and a phosphate group. At physiological pH (around 7), the phosphate group can deprotonate, leading to a negative charge.

In its structure, phosphatidonic acid contains a carboxyl group derived from the fatty acids that can also donate a proton depending on the pH, but at pH 7, it predominantly exists in a deprotonated state. The phosphate group, which is negatively charged at this pH, is responsible for the overall charge of phosphatidonic acid.

When considering the overall charge of phosphatidonic acid at pH 7, it is evident that it holds a net charge of -2 due to the deprotonation of both the phosphate group and the carboxylic acid component of the fatty acids. Hence, the correct charge of phosphatidonic acid at pH 7 is -2, indicating that this compound is negatively charged under physiological conditions.