Answer:
(E) Phosphoglucose isomerase (phosphohexose isomerase or glucose-6-phosphate isomerase)
Explanation:
Glyocolysis is break down of glucose into pyruvate.
Isomerization:The second step of glycolysis involves the conversion of glucose-6-phosphate to fructose-6-phosphate (F6P). This reaction occurs with the help of the enzyme phosphoglucose isomerase (PI). As the name of the enzyme suggests, this reaction involves an isomerization reaction.
Yeast mutant lacking phopshoglucose isomerase unable to performed this step and that's why it unable to grow in media containing glucose while in fructose break down this step is not required so it is able to grow in media containing fructose.
Deletion of phosphoglucose isomerase, prevents growth on glucose; therefore, phosphoglucose isomerase mutant is able to grown in a fructose medium.
