Phase 1: Acetyl Entry 

Phase 1: Acetyl Entry 

• This phase gets the molecule ready for the steps that follow. 

1. Acetyl CoA + Oxaloacetate → Citrate + CoA-SH

ENZYME: Citrate Synthase 

• This one is early to remember, as it literally synthesizes citrate! 

Note: This step is irreversible* 

→ Inhibited by: ATP, NADH, and Citrate 

2. Citrate → Isocitrate 

ENZYME: Aconitase 

• Now this name is not intuitive, so it may take some strange memorization tricks. For me, I know this reaction is a dehydration and rehydration reaction (meaning nothing is lost, just moved around), so I think of aconitase as “I can not trace” meaning that it moves things around but nothing is missing!