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This video provides a tutorial on regulation of glycolysis pathway. There are three important enzymes that regulate glycolysis pathway. 1. Hexokinase and glucokinase enzymes are allosterically activated by its substrate glucose. Hexokinase is allosterically inhibited by its product fructose-6-phosphate, whereas glucokinase is allosterically inhibited by fructose-6-phosphate. 2. Phosphofructokinase-1 (PFK-1) enzyme is allosterically inhibited by ATP and citrate, whereas it is activated by ADP, AMP and fructose-2,6-bisphosphate. 3. Pyruvate kinase enzyme is allosterically inhibited by ATP, acetyl CoA, alanine and long chain fatty acids, whereas it is activated by fructose-1,6-bisphosphate (an example of feed forward reaction). All three enzymes are inhibited by high glucagon in response to low blood glucose level. They are activated by high insulin in response to high blood glucose levels in the body.
The following topics are covered in this lesson,
1. Allosteric vs hormonal regulation
2. Allosteric regulation of hexokinase enzyme
3. Mechanism of glucokinase regulation in the liver
4. Hormonal regulation of glucokinase enzyme
5. Allosteric & hormonal regulation of phosphofructokinase enzyme
6. Regulation of fructose-2,6-bisphosphate in the liver
7. Role of phosphofructokinase-2/fructosebisphosphatase-2 enzyme in regulating fructose-2,6-bisphosphate
8. Allosteric and hormonal regulation of pyruvate kinase enzyme
9. Pyruvate kinase deficiency
10. Mechanism of arsenic poisoning