Absinthe is an emerald-green liqueur which was popular in the late 19 th century. It was banned by many countries by 1915. Considering the structure of the acetylcholine receptor, name an amino acid that could function as the gate for the Cl - channel which blocks the channel in the closed state and moves to open the channel when GABA binds. Describe briefly how this active form is generated from chymotrypsinogen. Chymotrypsinogen is cleaved by trypsin to form p -chymotrypsin.
Epinephrine binds to the receptor.
The a subunit of the G s , with GTP bound, activates adenylate cyclase. The cAMP binds to the regulatory subunits of protein kinase A, causing them to release from the catalytic subunits so that the enzyme is activated. Write out the pathway for the oxidation of pyruvate in the citric acid cycle. Indicate where the products of the citric acid cycle are formed. Label the steps catalyzed by regulatory enzymes.