Jeremy has been experiencing progressive muscular weakness and muscle cramps. He has also noticed that his symptoms (muscle aches and cramps) worsen with exercise and intermittent fasting and the new high-fat diet that he is currently testing out. Jeremy decided to finally take some action and seek medical attention. His doctor took a sample of his skeletal muscle and added some oleate to this skeletal muscle specimen and monitored the oxidation of oleate. The doctor also took a skeletal muscle specimen from a normal/healthy individual and again added oleate and monitored the oxidation of oleate. Jeremy’s doctor noticed that the skeletal muscle specimen from Jeremy oxidized oleate much more slowly than the skeletal muscle sample from the healthy individual. The doctor then added carnitine to the skeletal muscle sample from Jeremy and noticed that the rate of oleate oxidation equaled the control sample. The doctor diagnosed Jeremy with carnitine deficiency.
A) Why is it that the added carnitine increase the rate of oleate oxidation in Jeremy’s muscle homogenate? Explain.
B) Why were Jeremy’s symptoms more severe during periods of fasting, exercise, and the high-fat diet?
(A) During fatty acid oxidation, the carnitine mediated entry of fatty acids into the mitochondria is the rate limiting step.
A deficiency of carnitine slows fatty acid oxidation, while addition of carnitine increases the rate of oxidation.
(B) Periods of fasting, exercise, and the high-fat diet increase the metabolic need for fatty acid oxidation in the body. Thus, the symptoms become more severe.
Jeremy has been experiencing progressive muscular weakness and muscle cramps. He has also noticed that his...