Tutorial 3 - Metabolic Poisons Flashcards
Anoxaemia definition? What happens as a result?
Low oxygen levels in the blood - usually because most oxygen is being used up in respiration.
Erythropoeisis - makes more erythrocytes to try to alleviate the low oxygen levels.
Why does mitochondrial respiration depend on ADP?
ADP –> ATP
Oxygen consumption at the end of the ETC only occurs in the presence of substrate adn ADP.
Why is the rate of respiration in the presence of usccinate and ADP greater than with glutamate + malate +ADP.
Malates feeds electrons into the ETC via the first ETC complex NADH dehydrogenase - generating 3 ATP for each O2 –> H2O
Oxidation of succinate feeds electrons into the chain via FADH2, and succinate dehydrogenase. This only produces 2 ATP for every O2 –> H2O
to generate the same amount of ATP more succinate has to be oxidised than malate and glutamate, so more oxygen is used so RATE OF RESPIRATION IS HIGHER
What does adding cyanide do?
reacts covalently with Fe3+ in cytochrome oxidase, inhibits the terminal step of the ETC that respiration ceases.
What happens normally after adding Oligomycin?
Antibiotic that binds to ATP synthase stalk inhibiting it.
Can no longer use the H+ gradient, normally inhibiting respiration.
DNOC uncouples the mitochondria - Krebs cycle and ETC run maximally but link to generate ATP broken so free energy released as heat.
Large increase in mitochondrial oxygen consumption after addition of DNOC.
In this case why were the respiration and body temp elevated?
DNOC uncouples mitochondrial respiration so that the ETC runs max and without unproductively.
there is a buildup of H+ in the intermembrane space due to uncoupling. its released as heat.
Pulmonary ventilatio increases as the body tries to deliver more oxygen to respiring cells to increase ATP production.
Organ failure and death
Reason for post mortem findings?
fatty acids and triacylglycerols - used in respiration when they should be stored.
Tissue Hypoxia- due to excessive oxygen consumption
Red Marrow - due to increased erythropoeisis
Rigor Mortis- due to decreased concentration in ATP so contractile system is left contracted.
