page 03 3. Part of a metabolic pathway used by cells to produce the amino acid alanine is shown. pyruvate kinase phosphoenol pyruvate pyruvate alanine Alanine is a non-competitive, feedback inhibitor of the enzyme pyruvate kinase. The following statements refer to the metabolic pathway. 1 Pyruvate kinase reduces the activation energy needed to convert phosphoenol pyruvate into pyruvate. 2 Phosphoenol pyruvate is the substrate for pyruvate kinase. 3 Alanine can bind to the active site of pyruvate kinase. Which of these statements are correct? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 [Turn over