Question

Multiple Choice

1.) The mitochondrial form of the PEPCK enzyme, with oxaloacetate as substrate, is a(n) ................ enzyme for the Citric Acid Cycle

(a) inhibitory

(b) activatory

(c) anapleurotic

(d) catapleurotic

2.) In the cytosol of the cell, the PEPCK reaction is an enzyme in the pathway of:

(a) glycolysis

(b) gluconeogenesis

(c) glycogen synthesis

(d) pentose phosphate pathway

Answer 1

PEPCK enzyme is called as phosphoenolpyruvate carboxykinase. The PEPCK enzyme is used to convert oxaloacetate to phosphoenol pyruvate он PEPCK но он oxaloacetate phosphoenol pyruvate The PEPCK enzyme is a catapleurotic enzyme for the citric acid cycle. It catalyses the forward conversion of oxaloacetate to phosphoenol pyruvate Anapleurotic enzymes are the enzymes that catalyse the backward reaction of phosphoenol pyruvate to oxaloacetate. This reaction is not favoured by the PEPCK enzyme. PEPCK! participates in one replacement anaplerotic reactions which works in reverse direction of its normal function that is converting phosphoenol pyruvate to oxaloacetate. The kinetics are unfavourable for such reactions Inhibitorv enzymes are the enzymes that slow down the conversion of a substrate to a product. Activatorv enzymes are the enzymes that activate a substrate and fasten the conversion to the product. The correct option is (d The mitochondrial form of the PEPCK enzyme, with oxaloacetate as substrate, is a catapleurotic enzyme for the Citric Acid Cycle

Answer 2

d is the correct option