Pyruvate Dehydrogenase Flashcards
Potential fates of pyruvate:
- Cori Cycle: Lactate - Liver - Glucose;
- Acetyl co A
- Gluconeogenesis
- Alanine Cycle: Alanine - Liver - Glucose
What is pyruvate?
End product of glycolysis;
How does pyruvate enters in the mitochondria?
Outer membrane: a voltage-gate porin complex
Inner: mitochondrialpyruvate carrier (MPC);
Pyruvate is transported into mitochondria for:
Entry into TCA cycle
Gluconeogenesis
Function of Pyruvate Carboxylase:
Activate Gluconeogenesis;
Function of Pyruvate Dehydrogenase Complex:
Pyruvate is transformed into Acetyl coA - TCA Cycle
If acety-Co A is HIGH, Pyruvate Carboxylase is…
stimulated
Increases Gluconeogenesis
Inhibits TCA Cycle;
If ATP levels are HIGH, increases Gluconeogenesis.
TRUE
Vit B1 is Thiamine, when gets activated, it name is…
Thiamine Pyrophosphate;
Thiamine Deficiency causes less production of ATP.
Why?
Vitamin 1 (Thiamine) is converted to Thiamine Pyrophosphate that is a co-enzyme which is important in transform Pyruvate into acetyl-CO-A
Deficiency of thiamine causes BERIBERI and Wernicke Korsakoff syndrome.
TRUE
Beriberi - Dry type:
Polyneuritis, muscle Weakness;
Beribery WET type:
tachycardia, high output heart failure, edema;
Wernicke Korsakoff syndrome characteristics:
Alcoholics (malnourished, poor absorption vitamins)
Confusion confabulation
If glucose is given first to an alcoholic without thiamine, the risk of worsening Wernicke-Korsakoff is higher.
Why?
Just because without Thiamine is not possible to convert Pyruvate into acetyl co A.
FAD is synthesized from riboflavin B2.
Yes
NAD+ is synthesized from niacin B3.
Used in electron transport.
Tryptophan is used to synthesis NIACIN.
true
Vitamin B5 - pantothenic acid (b5) is used to synthesize Coenzyme A
TRUE
Cofactors for the pyruvate dehydrogenase complex:
B1-Thiamine
B2 - Ribolfavin FAD
B3 - Niacin (NAD)
B5 - Pantothenic Acid (CO A);
The lipoic acid is inhibited by….
Remember Napoleon
ARSENIC;
Inhibits PDH - like thiamine deficiency;
PDH (Pyruvate Dehydrogenase) Complex deficiency is a rare inborn error of metabolism. Often x Linked and most common cause of mutations in PDHA1 gene.
Most common IN MENS
Cannot effectively convert pyruvate into acetyl-coA.
When acetyl- coA is low, gluconeogenesis is…
Inhibited
In PDH complex deficiency, pyruvate is convevrted into Lactate and Alanine.
True
Key findings of PDH deficiency:
Poor feeding;
Growth failure;
Developmental delays
Labs findings in PDH deficiency:
Elevated alanine
Lactic acidosis
Mitochondrial disorders: inborne error of metabolism all cause sever…
LACTIC ACIDOSIS
- PDH deficiency
- Pyruvate carboxilase deficiency;
- Cytochrome oxidase deficiencies;
PDH complex deficiency:
Gives Thiamine, lipoic acid;
Ketogenic diet:
- Low carb, High fat, Ketogenic amino acids: lysine and leucine;
- Drives ketone production instead of glucose;
