Glucose Metabolism Flashcards
State the mechanism of glycolysis
Glucose is converted to Glucose-6-phosphate by Hexokinase (1 ATP is used)
Glucose-6-phosphate is converted to Fructose-6-phosphate by Phosphoglucose isomerase
Fructose-6-phosphate is converted to Fructose-1,6-bisphosphate by Phosphofructokinase (1 ATP is used)
Fructose-1,6-bisphosphate is converted to Dihydroxyacetone and Glyceraldehyde-3-phosphate by (Fructose bisphosphate) Aldolase
Dihydroxyacetone is converted to Glyceraldehyde-3-phosphate by Triose phosphate isomerase
Glyceraldehyde-3-phosphate is converted to 1,3-bisphosphoglycerate by Glyceraldehyde-3-phosphate dehydrogenase (NAD+ —> NADH)
1,3-Bisphosphoglycerate is converted to 3-phosphoglycerate by phosphoglycerate kinase (ADP —> ATP)
3-phosphoglycerate is converted to 2-phosphoglycerate by phosphoglycerate mutase
2-phosphoglycerate is converted to phosphoenolpyruvate with the removal of water by phosphopyruvate hydratase (Enolase)
Phosphoenolpyruvate is converted to pyruvate by Pyruvate kinase (ADP —> ATP)
NADH=Nicotidamide Adenine Dinucleotide
State the mechanism of glycogenesis during well-fed state
Glucose-6-phosphate is converted to Glucose-1-phosphate by phosphoglucomutase
Glucose-1-phosphate is converted to UDP-glucose by UDP glucose pyrophosphorylase
UDP Glucose is converted to Glycogen by Glycogen synthase
State the mechanism for glycogen degeneration
Glycogen is converted to Glucose-1-phosphate by Glycogen phosphorylase
Glucose-1-phosphate is converted to Glucose-6-phosphate by phosphoglucomutase
Glucose-6-phosphate is subsequently converted to pyruvate following the mechanism of glycolysis
State the mechanism for the conversion of glycogen to glucose
Glycogen is converted to Glucose-1-phosphate by Glycogen phosphorylase
Glucose-1-phosphate is converted to Glucose-6-phosphate by phosphoglucomutase
Glucose-6-phosphate is converted to Glucose by Glucose-6-phosphatase
State the mechanism of gluconeogenesis
Pyruvate is converted to Oxaloacetate by Pyruvate carboxylase (uses ATP)
Oxaloacetate is converted to Phosphoenolpyruvate by phosphoenolpyruvate carboxykinase (uses GTP)
Phosphoenolpyruvate is converted to 2-phosphoglycerate by phosphopyruvate hydratase (Enolase)
2-phosphoglycerate is converted to 3-phosphopyruvate by phosphoglycerate mutase
3-phosphoglycerate is converted to 1,3-bisphosphoglycerate by phosphoglycerate kinase
1,3-bisphosphoglycerate is converted to Glyceraldehyde-3-phosphate by Glyceraldehyde-3-phosphate dehydrogenase
Glyceraldehyde-3-phosphate is converted to Fructose-1,6-bisphosphate by Fructose bisphosphate aldolase
Fructose-1,6-bisphosphate is converted to Fructose-6-phosphate by Phosphofructokinase
Fructose-6-phosphate is converted to Glucose-6-phosphate by Fructose-6-phosphatase
Glucose-6-phosphate is converted to Glucose by Glucose-6-phosphatase
State the pathway for the conversion of Starch into Glucose
Starch is converted to Maltose by Diastase
Maltose is converted to Glucose by Glucosidase
State the pathway for sucrose to enter glycolysis
Sucrose is converted to Glucose and Fructose by Sucrase
Fructose is converted to Fructose-1-phosphate by Fructose kinase (Use ATP)
Fructose-1-phosphate is converted to Glyceraldehyde and Dihydroxyacetone by Fructose-1-phosphate aldolase
Glyceraldehyde is phosphorylated to Glyceraldehyde-3-phosphate by Triose kinase (Use ATP)
Glyceraldehyde can also be converted to Glycerol by Alcohol dehydrogenase (Use NADH) - Formation of Membrane Lipid
State the pathway for the conversion of glyceraldehyde to Phosphatidic acid (Not so important)
Glyceraldehyde is converted to glycerol by alcohol dehydrogenase
Glycerol is phosphorylated to L-glycerol-3-phosphate by Glycerol kinase
L-glycerol-3-phosphate and 2 acyl-CoA is converted to phosphatidic acid by enzyme Acyl transferase
L-glycerol-3-phosphate is converted to Dihydroxyacetone by Glycerol-3-phosphate dehydrogenase (use NAD and form NADH) (Proceed to gluconeogenesis)
State the various products that can be formed through phosphatidic acid (not so important)
Phosphatidic acid is converted to glycerol phospholipid by adding head group
Phosphatidic acid is dephosphorylated to Diacylglycerol by Phosphatidic acid phosphatase (convert ADP to ATP), which can be converted by Phosphatidic acid by Diacylglycerol kinase (uses ATP)
Diacylglycerol can be converted to monoacylglycerol and fatty acid by Lipase
Monoacylglycerol can be converted to Fatty acid and Glycerol by Lipase
Diacylglycerol can be converted to Triacylglycerol by Acyl transferase, which can be broken down to fatty acid and glycerol by Lipase
How is Acetyl CoA transported out of Mitochondria (Not important)
Pyruvate is converted to Oxaloacetate with the addition of CO2 by Pyruvate carboxylase (use ATP)
Acetyl CoA binds with Oxaloacetate to form Citrate by Citrate synthase
Citrate is transported out of mitochondria by Citrate transporter
Citrate is converted to Oxaloacetate and Acetyl CoA by Citrate lyase (use ATP)
Oxaloacetate is reduced to Malate by Malate dehydrogenase (NADH is used)
Malate is converted to Pyruvate using Malic enzyme with the removal of CO2 (NADP+ is converted to NADPH)
Malate can also enter mitochondria to undergo Krebs cycle by converting into oxaloacetate (NAD+ is converted to NADH)
State the mechanism of energy production in the preparatory step
Pyruvate is transported into mitochondria through pyruvate transporter
CoA is added to Pyruvate to Acetyl CoA by pyruvate dehydrogenase complex, NAD+ is reduced to NADH, 1 CO2 is released (Cofactors: Thiamine pyrophosphate, FAD, Lipoate)
State the mechanism in Krebs cycle
Acetyl-CoA and H2O is added to oxaloacetate to Citrate by Citrate synthase, CoA is removed
Citrate is dehydrated into cis-Aconitate and then Hydrated to Isocitrate by Aconitase
Isocitrate is decarboxylated to a-ketoglutarate by Isocitrate dehydrogenase with the release of CO2 and NADH is produced
a-ketoglutarate, with the addition of CoA is decarboxylated to Succinyl-CoA by a-ketoglutarate dehydrogenase complex, CO2 is released and NADH is produced
Succinyl-CoA is converted to Succinate by Succinyl-CoA Synthase, GTP is produced and CoA is removed
Succinate is converted to Fumarate by Succinate dehydrogenase, FADH2 is produced
Fumarate is hydrated to Malate by Fumarase
Malate is converted to Oxaloacetate by Malate dehydrogenase, NADH is produced
Describe Oxidative Phosphorylation in Electron Transport Chain
Oxidative Phosphorylation takes place in the inner membrane and the inter membrane space of the mitochondria
6H2O, 26-28 ATP is produced
Electron Transport Chain consist of
State the pathway for the production of Ketone body
2 Acetyl-CoA is converted to Acetoacetyl-CoA with the removal of Acetyl by Triolase
Acetoacetyl-CoA is converted into B-Hydroxy-B-methylglutaryl CoA with the removal of Acetyl from Acetyl-CoA and addition of H2O by HMG-CoA Synthase
B-Hydroxy-B-methylglutaryl CoA is converted to Acetoacetate by HMG-CoA Lyase
Acetoacetate is converted to Acetone (Ketone body) by Acetoacetate decarboxylase
Acetoacetate can also be converted to D-B-Hydroxybutyral by D-B-Hydroxybutyral Dehydrogenase
