Many solutes that must move into and out of cells exist in either a protonated or ionized form, or they have functional groups that can be either protonated or ionized. Simple molecules such as CO2CO2, H3PO4H3PO4 (phosphoric acid), and NH3NH3 (ammonia) are in this category, as are organic molecules with carboxylic acid groups, phosphate groups, and/or amino groups.

Instead of ammonia, consider the uptake of acetic acid. CH3COOH, an important intermediate in several biological pathways. What is the charged form in this case?

Question

Elliot Everett

Chemistry

1 March, 12:36

Many solutes that must move into and out of cells exist in either a protonated or ionized form, or they have functional groups that can be either protonated or ionized. Simple molecules such as CO2CO2, H3PO4H3PO4 (phosphoric acid), and NH3NH3 (ammonia) are in this category, as are organic molecules with carboxylic acid groups, phosphate groups, and/or amino groups.

Instead of ammonia, consider the uptake of acetic acid. CH3COOH, an important intermediate in several biological pathways. What is the charged form in this case?

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Answers (1)

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Missie · Answer 1

The correct answer is acetate (CH₃COO⁻)

Explanation:

Acetic acid (CH₃COOH) is a well-known organic acid. Since its dissociation constant is low (≅ 1.7 x 10⁻⁵), it belongs to the group of weak acids. Its pKa is aproximately 4.8, so at physiological pH (7.4), it losses the proton from the carboxylic group and forms the negatively charged molecule CH₃COO⁻ (acetate).