Question

Red blood cells lack nucleus and mitochondria in order to accommodate maximum space for hemoglobin, a principal means of delivering oxygen to different tissues.

Which of the following enzyme deficiencies could cause hemolytic anemia due to breakdown and loss of red blood cells?

	Ubiquinone oxidoreductase, complex I of the electron transport chain
	Succinyl-CoA synthetase, a Krebs cycle enzyme
	Isocitrate dehydrogenase, a Krebs cycle enzyme
	Pyruvate kinase, a glycolysis enzyme

Answer 1

Answer-

Pyruvate kinase, a glycolysis enzyme deficiencies could cause hemolytic anemia due to breakdown and loss of red blood cells.

Pyruvate kinase is a glycolysis enzyme deficiency of this enzyme leads to an inherited disorder that affects red blood cells, red blood cells carry oxygen to all the body's tissues. People having this disorder have a condition which is known as chronic hemolytic anemia, in which red blood cells are undergo hemolysis i,e broken down prematurely, leading to anemia which is the shortage of red blood cells.

Pyruvate kinase deficiency is due to mutations in the PKLR gene. which is active in the liver and in red blood cells, where it involved in oroduction of enzyme pyruvate kinase. The pyruvate kinase enzyme is involved in glycolysis (a energy-producing process). During glycolysis, glucose is broken down and produce adenosine triphosphate (ATP), which is the main energy source of a cell.

Mutations in PKLR gene results in reduced pyruvate kinase enzyme function, which leads to reduction of ATP in red blood cells and increased levels of other molecules produced in earlier steps of glycolysis. Then the abnormal red blood cells are gathered in spleen (graveyard of RBC) and destroyed, causes hemolytic anemia and enlargment of spleen.