DNA polymerase contains a lysine residue that is important for binding to DNA. Mutations were found that converted this lysine to either glutamate, glycine, valine, or arginine. Which mutations would be predicted to be the most and least harmful to the ability of the enzyme to bind DNA?

	Most	Least
(A)	Valine	Aspartate
(B)	Glycine	Arginine
(C)	Arginine	Glycine
(D)	Glutamate	Arginine

TLS Online TPP Program

#Question id: 24218

#Unit 1. Molecules and their Interaction Relevant to Biology

Phosphorylation of fructose 6-phosphate, catalysed by

TLS Online TPP Program

#Question id: 24219

#Unit 1. Molecules and their Interaction Relevant to Biology

When Fructose 2,6-bisphosphate binds to its allosteric site on PFK-1 results

TLS Online TPP Program

#Question id: 24220

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucagon stimulates cAMP from ATP. Cyclic AMP then activates cAMP-dependent protein kinase, phosphorylates PFK-2/FBPase-2. Phosphorylation of this protein enhances its FBPase-2 activity and inhibits its PFK-2 activity resulting

TLS Online TPP Program

#Question id: 24221

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucagon lowers the cellular level of fructose 2,6 bisphosphate by

TLS Online TPP Program

#Question id: 24222

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following reaction of glycolysis is irreversible

1. Glucose is converted to glucose 6-phosphate in the presence of the enzyme hexokinase.

2. Fructose 6-phosphate is converted to fructose 1,6-biphosphate in the presence of the enzyme phosphofructokinase.

3. Phosphoenolpyruvate is converted to pyruvate in the presence of the enzyme pyruvate kinase.

4. isomerization of glucose 6-phosphate to fructose 6-phosphate

TLS Online TPP Program

#Question id: 24223

#Unit 1. Molecules and their Interaction Relevant to Biology

Phosphoglycerate mutase catalyses a reversible shift of the phosphoryl group between C-2 and C-3 of glycerate; which of the following ion is essential for this reaction