Ketone Bodies And Vitamins Flashcards
Ketone bodies
Synthesized but not used in liver from fatty acid degradation (acetyl coA)
Used during prolonged fasting (after 3 days)
Ketone body metabolism (mitochondria)
Acetyl CoA (from FA degradation) broken into acetoacetate
Acetoacetate can become acetone or beta hydroxybutyrate
Hydroxybutyrate is broken down to acetyl coA in the tissues
Regulation of ketogenesis
Fed state: acetylCoA from glycolysis into TCA
Fasted: acetylCoA to ketone bodies
Lots of acetyl CoA and NADH shunts OAA into malate and ketone bodies
Ketoacidosis
Associated with type 1 diabetes because elevated glucagon (long term) mimics a fasted state:
Increase lipolysis, free fatty acids, hepatic output of ketone bodies = ketoacidosis
Vitamins
Water soluble: can’t store so no toxicity: B vitamins and C
Fat soluble: store in liver and adipose: all other letters
Thiamine (B1)
Cofactor for: PDH, alpha ketoglutarate dehydrogenase, transketolase, ketoacid dehydrogenase
Reduced ability to generate energy
Pyridoxine (B6)
Active: PLP
Cofactor for: amino acid metabolism and amino transferases
Homocycsteine to cysteine
Deficiency: peripheral neuropaty, skin inflammation, neurological degen
Biotin (B7)
Cofactor for: all carboxylases
Dementia: dermatitis, alopecia, enteritis
Folic acid (B9)
Active: THF: synthesis of methionine, purines, and dTMP
Deficincy: megaloblastic anemia, neural tube defects
Cobalamin (B12)
Coenzyme: methionine synthase, FA catabolism
Deficiency: pernicious anemia, dementia, spinal degeneration (look for MMA problems to distinguish from B9)
Ascorbic acid (C)
Iron absorption in GI tract, scavenging free radicals, collagen synthesis (wound healing, bone remodeling)
Deficiency: scurvy: sore spongy gums, loose teeth, swollen joints
Vitamin D
Steroid (fat soluble) hormone, regulation of gene expression
Photochemical synthesis or absorption from food
Regulate body calcium and phosphorus
Deficiency: rickets, osteomalacia
