Biology 1002B Lecture Notes - Lecture 7: Cellular Respiration, Anabolism, Endergonic Reaction

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ivorymarten910

12 Mar 2016

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When atp levels are low adp and amp levels are higher. If excess atp is present in the cytosol it binds to phosphofructokinase and therefore decreases 1,6- biphosphate concentration stops the reaction in glycolysis remainder or cellular respitation: also sensitive to citrate. There are catabolic pathways and there are other anabolic pathways: metabolism built around these pathways, free energy released from catabolic pathways drive anabolic pathways, so that"s really how metabolism is organized within a cell. Each individual step doesn"t have to be negative. How do you get it to proceed: energy coupling you couple the endergonic reaction with an exergonic reaction and the currency the use is atp. For almost every reaction we are using the energy from. Atp hydrolysis: the biosynthesis of glutamine from glutamic acid. Only thing that is that it"s a high energy phosphate. Molecule!: we couple the exergonic hydrolysis of atp to make this go. This reaction does not occur in the cell no.

Related Questions

Phosphofructokinase (PFK1) is a glycolytic enzyme that catalyzes the irreversible transfer of a phosphate from ATP to fructose -6-phosphate to form fructose-1, 6- bisphosphate.

fructose-6-phosphate + ATP --> fructose-1,6-bisphosphate + ADP

PFK1 is the key regulatory enzyme for glycolysis. When ATP levels are high in the cell, the cell no longer needs metabolic energy production to occur. In the case of these high energy levels, PFK1's activity is inhibited by allosteric regulation by ATP, which essentially closes the valve on the flow of carbohydrates through glycolysis.

Recall that allosteric regulators bind to a different site on the enzyme rather than the active (catalytic) site. ATP binds to the regulatory site and decreases PFK1 activity. ATP bound in the regulatory site acts as a modulator by lowering the affinity of PFK1 for its substrate, fructose-6-phosphate. AMP on the other hand, which is generated when the cell is in a low energy state binds to allosteric site and increases enzyme activity.

7. The enzyme PFK1 is an example of a non-regulatory enzyme or regulatory enzyme?

8. How is PFK regulated?

A. It is not regulated because it is a non-regulatory enzyme

B. allosteric enzyme regulation

C. covalent enzyme regulation

D. or proteolytic cleavage enzyme regulation?

9. What is the substrate and to which site on the enzyme does it bind? Which compounds are the positive and negative effectors?

10. In which conformational state would the enzyme be when negative inhibitors bind and in which conformational state would the enzyme be when positive inhibitors bind?

11. PFK1 is a heterotropic or homotropic regulatory enzyme?

12. Draw (or insert the picture from your course packet available on Canvas) the graph that corresponds to this reaction. Your graph should include the activity of PFK without bound effectors, with bound positive effector, and with bound negative effector. Label (or describe) each line to distinguish these along with which molecules are positive and negative effectors.

13. How does Vmax and K0.5 change with the positive and negative effectors?

Biology 1002B Lecture Notes - Lecture 7: Cellular Respiration, Anabolism, Endergonic Reaction

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