ATP and Biotin-Mediated Carbon Dioxide Activation

Flashcards covering the mechanisms of carbon dioxide activation by ATP and its subsequent transfer to biotin based on the lecture notes.

What molecule is formed when a nucleophile attacks the phosphate group of ATP during carbon dioxide activation?

Carboxyl phosphate, which is the activated form of carbon dioxide (or bicarbonate).

What is the role of ATP in the carbon dioxide activation process?

ATP provides an energy injection to make the overall reaction spontaneous and drive it forward.

How much energy is yielded from ATP hydrolysis as stated in the lecture?

Approximately $30.5\,kJ\,mol^{-1}$.

What is the total $\Delta G$ of the reaction mentioned in the transcript?

$32\,kJ\,mol^{-1}$.

What would happen to the reaction if ATP was not present?

It would be a reversible reaction that would not have much drive to occur.

How is the classical form of carbon dioxide ($CO_2$) generated from carboxyl phosphate?

A base in the enzyme active site pulls off a proton from the bicarbonate structure.

Which atom on biotin executes the nucleophilic attack to onboard carbon dioxide?

A nitrogen atom on biotin performs the nucleophilic attack after a base in the active site removes a proton.

What are the general steps to onboard carbon dioxide onto biotin?

First, ATP is used to activate carbon dioxide, and then biotin participates in a nucleophilic attack to onboard the carbon dioxide.