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24 Cards in this Set
- Front
- Back
Partitioning of glycolysis and glyconeogenesis is
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during exercise
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Glycogen metabolism
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oops
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glyconeogenesis
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how non-carbonhydrate goes back to glucose, pyruvate back to glucose. Primarily in liver and important during extendded exercise ,fasting and not a simple reversal of glycosis
3 irreversiable replaced by 4 step |
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Fructose 1,6 Bisphosphatase |
F‐1,6‐BP →F‐6P + Pi
Inhibited by AMP, F‐2,6‐BP Activated by citrate |
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Also Consider
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Consider:
F‐6P + ATP →F‐1,6‐BP + ADP F‐1,6‐BP →F‐6P Net: ATP →ADP + Pi |
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Feudal cycle is not good. Hence Important that F1,6BPase and PFK not operate simultaneously
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So, we need regulation
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If AMP is high , then ATP is low which mean that
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promote gluconeogenesis
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Partition of glycolysis and gluconeogenesis
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during exercise, pyruvate made faster in muscle than citric acid cylcle and can oxidized it -> lactate production.
Lactate in blood taken up by liver -> glucose. Lactate in Cory cycle |
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Well, Cardiac muscle has tons of mitochondria (mito) that could convert lactate
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so the blood stream must keep moving ( running to the bus in the morning )
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UDP and UTP glucose
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glucose is store as glycogen
Glucose 1 phosphate -> UDP-glucose |
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This reaction to convert glycogen to Glucose -1 phostphate catalyzed by
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glycogen phosphorylase.
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Glucose 1 P to G 6 P
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is catalyzed by phosphoglucomutase
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Blood glucose levels regulated by two hormones, glucagon and insulin
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Insulin released from pancreas when blood glucose is high, stimulates synthesis of glycogen from glucose.
Glucagon released from pancreas when blood glucose is low, stimulates the breakdown of glycogen to glucose |
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Another important hormon (adrenalin) . Muscular activity or its anticipation stimulates release of epinephrine(adrenalin) from adrenal medulla
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same as how glucagon works in liver.
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Glucagon binding to receptor on liver cell, or epinephinebinding on muscle cell activates
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adenylatecyclase: ATP → cAMP+ PPi
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cAMP is the second messager
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will activate protein kinase slnuatheus
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Activated PKA phoshorylatesGlycogen phosphorylasekinase(GPK)
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converts it to activeform
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Note
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Synthesis/breakdown of glycogen hormonally regulated via protein phosphorylation
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Activated GPK phosphorylatesGlycogen phosphorylase→
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converts it to activeform → breakdown of glycogen to G1P
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Glucagon is high
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in the morning to maintain the blood level glucose.
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Activated PKA phosphorylatesGlycogen synthase(GS) → converts it to inactiveform
Activated PKA phosphorylatesand activates inhibitor of phosphoproteinphosphatase(IP), turns off PP |
Hormonal activation → stimulation of glycogen breakdown to G1P, G6P
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After removal of hormonal stimulus, cAMPlevel drops: cAMPphosphodiesterase
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When cAMPdrops, PKA no longer active
Leads to inactivation of IP, activation of Phosphoproteinphosphatase Removal of phosphates from GP and GPK → conversion back to inactive forms Removal of phosphate from GS → conversion back to active form Removal of hormone → conversion of G1P, G6P to glycogen |
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Oxidative states of metabolism
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Kreb's cycle
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The tricarboxylic acid (TCA) cycle (Krebs cycle)
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Common pathway for fuel molecule (carb’s, fats, aa’s) oxidation
Carb’s →pyruvate →acetyl CoA Allows recovery of much greater portion of free energy than glycolysis Occurs in mitochondria |