Turco 3 Flashcards
Glc gives up how many total pairs of electron
12 pairs
1 in glycolysis to pyruvate
5 from pyr to CO2
Step of glycolysis giving up electrons
Glyceraldehyde 3P —-> 1,3 BPGT
Pyruvate dehydrogenase complex
Takes pyruvate to acetyl CoA
Located in Mitochondria
Releases pair of electrons
Isocitrate dehydrogenase
Takes isocitrate to alpha ketoglutarate
Creates NADH from NAD
Regulation of isocitrate dehydrogenase
Turned off by high levels of ATP and NADH…this will increase concentration of citrate that then inhibits PFK1 of glycolysis in EXTRAhepatic cells
Creatine and ATP
ATP cannot be stored in cells so phosphate added to creatine for storage
Creatine kinase isoforms
Skeletal muscle - MM
Brain - BB
HEart - MM and MB isoform
Importance of MB isoform
Indicative of heart attack…creatine kinase will spill out into the bloodstream and be present for about 24 hours
Creatine metabolism
Creatine converted to creatine phosphate using ATP
Creatine phosphate turns into creatinine nonenzymatically with release phosphate
In very short burts?
ATP levels stay relatviely the same (enzyme that takes 2 ADP to ATP+AMP)
Creatine-P will decrease dramatically
Also lactic acid
Intermediate energy expenditure
Mix of fatty acid and aerobic
Long term energy expenditure
Glycogen is gone so increased fatty acid metabolism
TG metabolism in adipose
HSL activated by epinephrine and cortisol, decreased by insulin
Phosphorylated enzyme takes TGs to Glycerol and FAs
TG metabolism in liver
Glycerol moved into liver and taken to glucose via gluconeogenesis (activated by glucagon and cortisol)
FA moved into liver and unergo B-oxidation to AcCoA
AcCoA either goes to krebs or undergoes ketogenesis to form ketone bodies
When will TG metabolism start
90 minutes after last carb
No receptor for glucagon in
Adipose tissue
Insulin, epinephrine, and cortisol mech of HSL
Insulin - dephosphorylate
Epi - phosphorylate
Cortisol - genomic level
Why is B-oxidation important?
Creates energy necessary to drive gluconeogenesis
Why would defect in B-oxidation cause SIDS?
Can’t drive gluconeogenesis so hypoglycemia
Ketogenesis, B oxidation and gluconeogensis locations
Keto and gluco in liver only
B-oxidation can be in other cells
Atkins diet rationale
Keep insulin low by decreasing carbs in diet…this means HSL always active
Problem with atkins diet
Used muscle proteins from glucogenic amino acids to make appropriate glucose
Other probs with atkins
Excessive N secretion (kidney)
Body is in long term ketosis
FA transport into matrix for oxidation
CoA added to FA when bringing in through outer membrane…CoA then removed and FA transferred to carnitine by CAT…moved through inner membrane…CAT 2 removes carnitine and makes FA-CoA again
FA-CoA in the matrix
Processed by LCAD, MCAD, or SCAD and forms FADH2…also form NADH…2 carbons removed in form of Ac-CoA
This is repeated until down to four and then split into 2 Ac-CoA
KB metabolism
2 acetyl CoA get to acetoacetate
Acetoacetate forms B-hydroxybutyrate with NADH OR decarboxylated to form acetone
Acetoacetate and B-hydroxybutyrate moves out of blood
How are ketone bodies used
Broken down into 2 acetyl CoA inside extrahepatic cells
Hallmarks of ketosis
INcreased KBs leads to ketonemia (bad bc pH will drop)
Increased KBs in urine leads to ketonuria….bad because dehydration
Acetone breath (fruity odor)
Myopathic canitine deficiency presentation
Elevated muscles TGs and reduced muscle carnintine onyl…muscle weakness severe during exercise
Myopathic carnitine deficiency pathology
Could be defect of CAT enzymes, transporters, or error in carnitine creation
FAs will stay in the muscle cell and TGs cannot exit the muscle
Epinephrine activates adipose tissue and triggers HSL…TGs breakdown and enter cells…FA cannot go into matrix to be burned
MCAD def presentation
Hypoglycemia and hypoketonemia
Dicarboxylic acidemia (from omega oxidation)
C8/C10 acylcarnitines in blood
MCAD def pathology
Hypoglycemia because without MCAD, cannot power gluconeogenesis…normally hypoglycemia means hyperketonemia
Propionate metabolism
5 carbon fragment split to acetyl CoA and proprionyl CoA (3 carbons)
Propionyl CoA carboxylase takes propionyl CoA to methylmalonyl CoA using (ATP, biotin, CO2)
Methylmalonyl CoA mutase takes methylmalonyl CoA to succinyl CoA using coenzyme form of Vit B12
Propionyl CoA also made from
Val, Met, Ile, and Thr
If priopionyl CoA carboxylase borken
Propionic acid in the urine and blood
Defect in methylmalonyl CoA mutase
Causes methylmalonic acidemia and gives rise to peripheral neuropathy as integrated into myelin sheaths
Causes of methylmalonyl CoA mutase def
B12 def IF def (binds to B12 to absorb) Mutase defect Defect in coenzyme form of B12 (can't convert
