The synthesis of essential aromatic amino acids proceeds through a pathway that includes a key intermediate, chorismate. The carbon atoms of chorismate are derived from phosphoenolpyruvate and erythrose 4‑phosphate. A six-membered carbon ring which is attached to a negatively charged carboxyl group at position 1. Carbon 1 is double bonded to carbon 2. Carbon three is single bonded to an oxygen, this oxygen is single bonded to carbon which is double bonded to C H 2 and single bonded to a negatively charged carboxyl group. Carbon 3 is also single bonded to hydrogen. Carbon 4 is single bonded to a hydroxyl group and a hydrogen. Carbons 5 and 6 are joined by a double bond. How many of the carbon atoms of chorismate are derived from the glycolytic intermediate?