Substrate level phosphorylation in Glycolysis is seen in which step?
ANSWER: (B) Pyruvate kinaseREF: Murray pp 130-135, Scriver, pp 1521-1552, http://en.wikipedia.org/wiki/Substratelevel_phosphorylationSubstrate-level phosphorylation is a type of metabolism that results in the formation and creation of adenosine triphosphate (ATP) or guanosine triphosphate (GTP) by the direct transfer and donation of a phosphoryi (POa) group to adenosine diphosphate (ADP) or guanosine diphosphate (GDP) from a phosphorylated reactive intermediate. Note that the phosphate group does not have to directly come from the substrate. By convention, the phosphoryl group that is transferred is referred to as a phosphate groupWe use the term substrate level phosphorylation because ATP formation in glycolysis is powered by the addition/ removal of phosphate groups (phosphorylation) to molecules of glucose (the substrate). Hence the term substrate-level phosphorylation.Examples of substrate level phosphorylation that occurs in glycolysis is:The production of 1st ATP when 1,3 bisphophoglycerate is converted into 3-phosphoglycerate by the enzyme phosphoglycerate kinaseProduction of 2nd ATP when phosphoenolpyruvate is converted to pyruvate by the enzyme pyruvate kinase.
Glyceraldehyde 3 Phosphate dehydrogenase
Pyruvate kinase
Phosphofructokinase
Enolase
Respiratory Chain