tailieunhanh - Introduce of metabolism at a glance (Fourth edition): Part 2

(BQ) Continued part 1, part 2 of the document Introduce of metabolism at a glance (Fourth edition) has contents: Metabolism of glucose to fatty acids and triacylglycerol, elongation and desaturation of fatty acids, fatty acid oxidation and the carnitine shuttle, ketone bodies, ketone body utilization, and other contents. Invite you to refer. | Metabolism of glucose to fatty acids and triacylglycerol 27 A brief description ofhow glucose is converted to fat appeared in Chapter 26. It is now time to look at triacylglycerol biosynthesis in more detail. The liver adipose tissue and lactating mammary gland are the principal tissues involved in lipogenesis triacylglycerol synthesis . Liver and adipose tissue make triacylglycerol from glucose under conditions of abundant carbohydrate intake in other words when the body has more than enough food to satisfy its immediate needs for energy. Chart synthesis of triacylglycerols from glucose Importance of citrate in activating fatty acid synthesis The mitochondrion in the high-energy state has increased amounts of ATP and NADH. These metabolites both symbols of cellular affluence reduce the rate of flow of metabolites through Krebs cycle by inhibiting isocitrate dehydrogenase. Consequently the metabolites isocitrate and citrate accumulate and their concentration within the mitochondrion increases. As the concentration of citrate rises it diffuses via the tricarboxylate carrier from the mitochondrion into the cytosol where citrate serves three functions 1 Citrate and ATP are allosteric regulators that reduce the metabolic flux through glycolysis by inhibiting phosphofructokinase-1 thereby redirecting metabolites into the pentose phosphate pathway. This pathway produces NADPH which is an essential coenzyme for fatty acid synthesis. 2 Citrate in the cytosol is split by citrate lyase the citrate cleavage enzyme to form oxaloacetate and acetyl CoA. The latter is the precursor for fatty acid synthesis. 3 Citrate activates acetyl CoA carboxylase which is a regulatory enzyme controlling fatty acid synthesis. In these three ways citrate has organized the metabolic pathways of liver or fat cells so that lipogenesis may proceed. Pentose phosphate pathway generates NADPH for fatty acid synthesis To reiterate once the immediate energy demands of the animal have been satisfied

• Y khoa - Dược
• Ketone body utilization
• Ketone bodies
• Phenylalanine and tyrosine metabolism
• Glucose to fatty acids
• The carnitine shuttle
• Porphyrin metabolism