Metabolic Pathways

[pangolin123]

Hello Guys, I got a qn and my teacher ask me to find on these.

Explain why the pathways that you have learnt are interlinked. Provide some examples.

Any help would be appreciated. Thanks

[RobJim]

Well, what pathways have you learned?

[sdekivit]

the main 3 metabolic pathways are the glucosemetabolism, fatmetabolism and the oxidative phosphorylation. Proteins are put in the glucose metabolism or the fatmetabolism. I guess you meant these pathways.

[RobJim]

Well, in glucose metabolism, the glycolytic pathway breaks glucose into two molecules of pyruvate, which then is generates acetyl CoA. The acetyl CoA then enters the citric acid cycle and are oxidized to CO2.

In response to hormones like adrenaline, triacylglycerols (fats) are hydrolized in the cytosol to free fatty acids and glycerol. In the cytosol free fatty acids are esterified to coenzyme A to form a fatty acid CoA. In the mitochondrion, fatty acid CoA is converted to acetyl CoA which then enters the citric acid cycle just like in glucose metabolism.

The NADH and FADH2 formed during glucose metabolism is involved in making ATP from ADP and Pi in oxidative phosphorylation.

[sdekivit]

Originally Posted by RobJim

Well, in glucose metabolism, the glycolytic pathway breaks glucose into two molecules of pyruvate, which then is generates acetyl CoA. The acetyl CoA then enters the citric acid cycle and are oxidized to CO2.


this is only when there's oxygen When there's no oxygen, then lactate or ethanol will be formed. The lactate will participate in the Cori-cycle.

In glucose metabolism is gluconeogenesis also involved. This is not just a reverse from the glycolysis


In response to hormones like adrenaline, triacylglycerols (fats) are hydrolized in the cytosol to free fatty acids and glycerol. In the cytosol free fatty acids are esterified to coenzyme A to form a fatty acid CoA. In the mitochondrion, fatty acid CoA is converted to acetyl CoA which then enters the citric acid cycle just like in glucose metabolism.

when triacylglycerols are use, the glycerol can be converted to dihydroxyacetonephosphate by glycerolkinase and glycerol-3-phosphate dehydrogenase and can then be burned in the glycolysis or can be used to form glucose. Out of fat glucose can thus be formed.

The burning of fat takes place in the beta-oxidation. In contrast to fatburning, fat synthesis takes place in the cytosol, because the reactionstep where thiolase is the enzyme lays strongly to the hydrolysis side.

The NADH and FADH2 formed during glucose metabolism is involved in making ATP from ADP and Pi in oxidative phosphorylation.

during the glycolysis only NADH is formed. FADH2 is formed in the beta oxidation of the fat metabolism and during the Krebs-cycle.