pengantar metabolisme
TRANSCRIPT
Metabolisme
Susila Sastri
Metabolisme
• Definisi: rangkaian reaksi-reaksi kimia dalam sel yang terjadi secara continue dan saling berhubungan satu dengan yang lain– Anabolisme – Katabolisme– Ampibolic
Overview Metabolisme
Metabolisme
• Bahan bakar tubuh : carbohydrates, fats, dan proteins
( makromolekul)
• Energi : oxidasi :CO2 and H2O.
• Cadangan dalam tubuh : triacylglycerol (fat), glycogen (carbohydrate)
• Penurunan atau penambahan BB normal: Energi dipakai – Energi tersedia
• insulin dan glucagon; regulator pemakaian dan penyimpanan bahan cadangan
• Karbohidrat utama dalam darah : glukosa : regulator insulin dan glukagon dalam darah
Puasa
• Puasa : hypoglisemia , memicu pamkreas agar glukagon disekresi
• Glucagon: cadangan carbohydrat membebaskan glucose ke sirkulasi ( brain)
• Puasa lebih 3 : ketone bodies (derived from fat) as an alternative fuel supply for the brain.
Anabolisme• Biosintesis senyawa biomolekul (glikogen,
protein, trigliserida)• Butuh Energi (endergonic). • ATP: ADP + Pi (ATP-ADP cycle)• Misal
– Glikogenesis– Glukoneogenesis– Biosintesa asam lemak– Biosintesa protein
Katabolisme
• Pemecahan molekul besar : molekul kecil (glukosa, asetil KoA, Asam amino) CO2 dan Energi (ATP)
– CO2 : sirkulasi– ATP : dibebaskan setelah elektron
ditransfer ke O2
• Mis: – Glikolisis– Glikogenolisis– Oksidasi asam lemak
Amphibolic
• Anabolisme dan Katabolisme: terjadi dalam satu proses metabolism
• Siklus Kreb– Biosintesis heme, glukosa, asam lemak– Katabolisme: sitrat, ketoglutarat
Energi
• Oxidation of fuels to generate ATP is called respiration • Electrons lost from the fuels during oxidative reactions :
transferred to O2 by a series of proteins in the electron transport chain
• Energy of electron transfer : used to convert ADP and Pi to ATP by a process known as oxidative phosphorylation
• Satuan Energi :– Calori– kilocalorie – kilojoules (kJ)
The ATP-ADP cycle
Generation of ATP
approximate order in which the processes occur. TG = triacylglycerols; FA = fatty acid; AA = amino acid; RBC = red blood cell; VLDL = very low density lipoprotein; I= insulin; % = stimulated by.
Metabolisme KH, Fat AA
TAG = triacylglycerol
Overview Metabolisme KH
Overview of fatty acid metabolism
Overview of amino acid metabolism
Transport and fate of major carbohydrate and amino acid substrates and metabolites
Transport and fate of major lipid substrates and metabolites
FFA, free fatty acids; LPL, lipoprotein lipase; MG, monoacylglycerol; TG, triacylglycerol; VLDL, very low density lipoprotein.
Intracellular location and overview of major metabolic pathways