BIOL 201 Lecture Notes - Lecture 5: Warburg Effect, Negative Feedback, Pyruvic Acid
26 Jan 2016
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Document Summary
Enzymes that catalyze irreversible steps are all allosterically regulated. The conversion of glucose to glucose-6-phosphate is inhibited by g-6p. The conversion of fructose-6-phosphate to fructose-1,6-bisphosphate is inhibited by atp, citrate, h+, and activated by amp, f-2,6-bp. The conversion of phosphoenolpyruvate to pyruvate is activated by f-1,6-bp and inhibited by atp. When the ph is too low, e. g. anaerobic glycolysis, you accumulate lactic acid b/c you use up atp faster so it"s harder for the muscles to work. There are 2 atp binding sites: 1 catalytic and 1 regulatory. Atp bound at regulatory site lowers affinity for f-6p. Citrate (tca cycle) enhances atp inhibition (liver only) Pfk is also inhibited by low ph: prevents excessive accumulation of lactic acid. When we use atp at a high rate, the concentration of amp goes up. Increases affinity for f-6p, decreases inhibitory effect of atp. High blood glucose = increased f6p: traps glucose in the cell.
