Metabolism of Nutrients in Muscle and Adipose Tissue

Metabolism of Nutrients in Muscle and Adipose Tissue Anusorn Cherdthong, Ph. D 137748 Applied Biochemistry in Nutritional Science Email: anusornc@kku. ac. th E-learning: http: //ags. kku. ac. th/e. Learning/137748

Introduction ØProtein and lipid are more importance role in muscle and tissue ØStorage and excretion when required ØSome metabolism are similar to liver metabolism ØMuscle cell---protein storage ØAdipose tissue---triacylglyceride storage

Metabolism in muscle cell Riis (1983)

Metabolism pathway In muscle cell q. Protein synthesis q. Protein lysis In adipose tissue q. Triacylglyceride degradation q. Triacylglyceride storage q. Lipogenesis q. Control of fatty acid synthesis

Protein synthesis q. Transcription: messenger RNA (m. RNA), ribosomal RNA (r. RNA), transfer RNA (t. RNA) and small nuclear RNA (sn. RNA) q. Initiation q. Elongation q. Termination q. Translation q. Initiation q. Elongation q. Termination

Protein synthesis in muscle Mc. Donald et al. (2011)

t. RNA molecule Mc. Donald et al. (2011)

RNA Translation Mc. Donald et al. (2011)

Protein lysis q. Required proteinases q. Lower rate than liver—low proteinases q proteinases enzymes qcathepsin D qalkaline proteinases: Ca 2+-activated proteinase or –factor (CAF) q. Low protein lysis low protein synthesis q. Stress---high protein lysis

Lipid metabolism q. Occurred at adipocyte of adipose tissue q. Control—triacylglyceride, free FA q. Provide various substances--- adipokine q. Induce by hungry, diets, digestion/absorption system, hormone, CNS etc

Metabolism in adipose tissue Riis (2983)

Triacylglyceride degradation q. Control by hormone system q. End products are FA and glycerol q. FA—oxidation---energy (95%) q 5% energy from glycerol

Triacylglyceride degradation Nelson and Cox (2000)

Triacylglyceride degradation control Nelson and Cox (2000)

Triacylglyceride storage q. Increase after feeding q. LDL synthesis at adipose—induce by insulin qglycolytic enzyme phosphofructokinase-1 ---. >fructose 2, 6 bisphosphate q Fatty acyl Co. A + glycerol-3 phosphate- triacylglycerol q. Insulin induce glucose - FA

Lipogenesis q. In ruminant occurred 92% in adipose tissue q. Substrate: C 2 and C 4 q. Energy from NADPH, ATP q NADPH—isocitrate and oxaloacetate q. In non ruminant occurred in liver q. Substrate: glucose q. NADPH---pentose shunt --malate dehydrogenase

FA syvthesis in adipose tissue of ruminant Van Soest (1982)

Control of fatty acid synthesis q Hormone controlled q. Insulin: induce FA synthesis q. Transfer glucose into cell q. Activated pyruvate dehydrogenase q Enzyme: qacetyl-Co. A carboxylase acitvate by citrate q. NADPH

Conclusion 1 Protein and lipid are major metabolism 2 3 4 Muscle storage protein while adipose was storage tryacylglyceride Protein metabolism: RNA transcription, translation Triacylglycerols metabolism was differ among specie animals

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