Question

Description: In order to go from glycolysis to the citric acid cycle we first must harvest pyruvates into acetyl CoA’s. This process involves many small steps which result in the main entrance in the citric acid cycle

Instructions: For this presentation, your goal is to walk the audience through every step that is involved in generating acetyl CoA from Pyruvate. Be sure to focus on any cofactors need and show how this process is reset at the end to allow for another pyruvate molecule to bind.

Answer 1

pyruvate dehydrogenase complex (mixture of 3 distinct enzymes)is responsible for the conversion of pyruvate to acetyl CoA

Step1:Pyruvate produced in cytosol and transfered to mitochondria.oxidative decarboxylation of pyruvate takesplace with the help of pyruvate dehydrogenase enzyme,a molecule called TPP form temporary bond with pyruvate

Step2: The enzyme dihydrolipoyl transacetylase helps to attach other molecule lipoamide,and TPP from first step is removed to form an acetyl group

Step3 : The CoA group attacks the acetyl groupand forms acetyCoA and lipoamide released in reduced form.

Step4:lipoamide reoxidized with the help of dihydrolipoyl dehydrogenase and also NAD become NADH while oxidising lipoamide. so that in the next cycle lipoamide can be used