Term
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Definition
GLUT1: RBC transporter.
GLUT2: Liver,Kidney. Insulin independent
GLUT4: Muscle, adipocyte, Heart
Insulin-Dependent
GLUT5: Spermatozoon. Fructose |
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Term
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Definition
Liver, Beta-cells.
Sensor, Regulator of Plasma glucose
Vmax High, Km = 10mM(Low affinity)
Inhibited by F-6-P
High plasma Glu -> GLUT-2 recruitment
to membrane. |
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Term
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Definition
Most tissues
Fast glucose uptake
Inhibited by G-6-P
Low Vmax. Km 0.1mM(High affinity) |
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Term
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Definition
Phosphoenol Pyruvate + ADP -> pyruvate + ATP
Large quantities and highly active
Inhibitors: ATP, Acetyl-CoA
Activators: F1,6Bis-P(feed forward)
Glucagon -> PKA -> phosphorylates(inhibits, only in liver) |
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Term
Pyruvate Kinase Deficiency
and others |
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Definition
Autosomal Recessive.
Increase 2,3 BPG and low ATP
Most RBC enzymopahties are AR except Phosphoglycerate Kinase(X-linked)
Bisphosphoglycerate mutase -> absence of 2,3-BPG |
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Term
| LDH maintains glycolytic Flux by |
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Definition
Maintaining cells High NAD+/NADH ratio
Glyceraldehyde-3-P deh produces NADH
LDH(pyruvate -> lactate) turns NADH back into NAD+
LDH active in RBC, Cornea of eye, testes |
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Term
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Definition
F-6-P -> F-1,6-P
ATP -> ADP
Coenzyme: Mg +2
Activator: AMP, F-2,6BP
Inhibitor: ATP, Citrate
Major rate limiting after HK |
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Term
| Fructose 2,6 Bisphosphate(FBP-2) |
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Definition
PFK-2 synthesizes F-26BP when
dephosphorylated in liver
FBPase-2 Degrades F-2,6-BP when phosphorylated in liver
Reverse in heart |
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Term
Heart Vs Liver.
Glucagon, Epinephrine |
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Definition
Liver: GLucagon -> phosphorylation of
PFK2/FBPase2. Causes degradation of
FBP-2 and inhibits glycolysis
Heart: Epinephrine -> Phosphorylated
PFK2/FBPase2, synthesizes FBP-2.
Activates glycolysis |
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Term
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Definition
Pyruvate is decarboxylated and oxidized by pyruvate dehydrogenase to form Acetyl CoA in mitochondria.
Pyruvate Carboxylated to form oxaloacetate. via pyruvate carboxylase |
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Term
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Definition
Providers:
Liver(90%) Kidney Cortex(10-40) Starvation
Users:
Brain, kidney medulla, RBC, Testes |
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Term
Pyruvate -> Oxaloacetate
(gluconeogenesis) |
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Definition
Carboxylation of Pyruvate by Pyruvate
Carboxylase
Pyruvate + Co2 -> Oxaloacetate
Uses ATP
Biotin is coenzyme(binds Co2)
Activator: Acetyl-CoA, high ATP
In mitochondria |
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Term
Oxaloacetate -> Phosphoenol Pyruvate
Gluconeogenesis |
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Definition
Oxaloacetate -> Malate to be moved out of mitochondria than back to Oxaloacetate.
PEP carboxykinase(MG+2) required
OAA + GTP -> GDP + CO2 + PEP |
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Term
| Frucotose 1,6 bisphosphatase. FBPase-1 |
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Definition
F-1,6-BP -> F-6-P
Inhibited by F-2,6-Bis-P and AMP |
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Term
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Definition
Active site in ER lumen
G-6-Pase: high activities in Liver, Kidney, β-Cells. |
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Term
| Main precursors of gluconeogenesis |
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Definition
Lactate
Ketoacids(Alanine, aspartate, glutamate)
Glycerol: From triglycerides
Propionyl-CoA |
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Term
| Liver Acinus. Arterial vs Venous |
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Definition
Cells close to arterial: ATP-using enzymes
Gluconeogenesis, ureagenesis.
Cells closer to venules: Glycolysis and
glycogenesis. |
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Term
Cori Cycle
Glucose-alanine Cycle |
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Definition
Cori cycle:
Lactate produced in muscle travels to
liver. NAD+ in liver transforms
lactate to pyruvate to Glucose
Glucose-Alanine Cycle:
In muscle pyruvate -> Alanine Via glutamate + NH4+ -> α-ketoglutarate.
Reverse in Liver, production of NH4 for urea cycle. |
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Term
| Ethanol And Gluconeogenesis |
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Definition
ADH: Ethanol + NAD -> acetylaldehyde + NADH
ADH inhibited by disulfiram
Rise in NADH -> Rise in lactate, malate
Excessive EtOH intake -> hypoglycemia
Malate -> pyruvate + CO2 + NADPH
Rise in hepatic NADPH favors lipid production |
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Term
| Von Gierke's(glycogenosis I) |
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Definition
G-6-Pase. most common mutation.
Hypoglycemia, profound, liver specific
If G-6-Pase:
G-6-P -> G-1-P via PGM
G-1-P + UMP -> UDP-glucose -> glycogen.
Severe lactic acidoses |
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