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Metabolism key concepts

5 revision pages for Metabolism, each with the key facts, a memory aid where one helps, and the exam traps.

  1. Carnitine shuttle and long-chain fatty acid entry into mitochondria

    The carnitine shuttle uses carnitine, a small carrier molecule, to carry long-chain fatty acids into the matrix (the inner compartment) of the mitochondrion for energy production.

  2. Familial hypercholesterolaemia and the defective LDL receptor

    Familial hypercholesterolaemia (FH), an inherited condition of high LDL cholesterol, is usually caused by a faulty LDL receptor, so the liver clears LDL slowly.

  3. Liver glycogen versus muscle glycogen

    Liver glycogen can raise blood glucose because liver cells have glucose-6-phosphatase, the enzyme that removes the phosphate from glucose-6-phosphate (glucose carrying a phosphate), giving free glucose (glucose without the phosphate).

  4. NAD+ regeneration by lactate dehydrogenase in anaerobic glycolysis

    Lactate dehydrogenase, the enzyme that turns pyruvate into lactate, converts NADH back into NAD+ (an electron carrier), so step 6 of glycolysis can keep running when oxygen is limited.

  5. Why older adults are prone to hypothermia

    Older adults are prone to hypothermia (a core body temperature below 35°C) because they retain heat less well and make less of it in the cold.

Practice Metabolism questions