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Wt's is carbohydrate oxidation

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carbohydrate metabolism AND oxidation

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carbohydrate oxidation definition metabolism

Carbohydrate oxidation is the process by which the body breaks down carbohydrates, mainly glucose, to release energy in the form of ATP.
In the presence of enough oxygen, the overall reaction is:
Glucose + oxygen → carbon dioxide + water + ATP (energy)
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
Main steps:
  1. Glycolysis: glucose is split into pyruvate in the cytoplasm.
  2. Pyruvate oxidation and Krebs cycle: pyruvate is processed in mitochondria, producing carbon dioxide.
  3. Electron transport chain: oxygen is used to make most ATP and water.
During intense exercise with insufficient oxygen, glucose may instead be incompletely broken down to lactate, producing less ATP.
So, simply: carbohydrate oxidation means using sugar stored in blood or glycogen stores as fuel for the body. Textbook physiology describes complete carbohydrate oxidation as producing CO₂ and water.

Wt's the reason behind pdhnot working properly

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pyruvate dehydrogenase deficiency

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pyruvate dehydrogenase complex deficiency causes thiamine regulation NADH acetyl CoA

PDH means the pyruvate dehydrogenase complex. It converts pyruvate from glycolysis into acetyl-CoA, which then enters the Krebs cycle to make energy.
PDH may not work properly for two main reasons:
  1. It is switched off physiologically
    • When energy is already abundant, high ATP, NADH, and acetyl-CoA activate PDH kinase.
    • PDH kinase phosphorylates PDH, making it inactive.
    • This prevents additional glucose from being burned when the cell already has sufficient energy.
    • PDH is switched back on by PDH phosphatase through dephosphorylation. Basic Medical Biochemistry - A Clinical Approach, 6e, section “Regulation of the Pyruvate Dehydrogenase Complex.”
  2. A cofactor or enzyme is deficient PDH needs five cofactors:
    • Thiamine (vitamin B1/TPP)
    • Lipoic acid
    • CoA from vitamin B5
    • FAD from vitamin B2
    • NAD⁺ from vitamin B3
    Therefore, especially thiamine deficiency can reduce PDH activity. Pyruvate then cannot become acetyl-CoA efficiently and is diverted to lactate, which can contribute to lactic acidosis.
  3. Inherited PDH-complex deficiency
    • Mutations affecting PDH components, most commonly PDHA1, can cause a genetic PDH deficiency.
    • This impairs energy production, particularly in the brain, and can cause elevated pyruvate and lactate, developmental delay, hypotonia, seizures, or other neurologic problems. MedlinePlus Genetics summary describes PDHA1-related defects as the commonest cause.
In short: PDH is impaired when it is deliberately inhibited by a high-energy state, when it lacks needed vitamin-derived cofactors, especially B1, or when there is an inherited enzyme defect.
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