Case 1
Pyruvate dehydrogenase complex (PDHC) deficiency
This is a fairly rare genetic disorder. The enzyme thatconverts pyruvate to acetyl CoA is deficient. How will cellrespiration be affected? What symptoms will be observed?
For more information, perform an Internet search using"pyruvate dehydrogenase complex (PDHC) deficiency" asthe search terms.
Case 2
Mitochondrial cytochrome b deficiency
Cytochrome b is part of the electron transport chain inmitochondria. In this rare genetic disorder, only themitochondria in the muscle are affected. Very early intheir embryonic development, a mutation occurred in the cytochrome b gene in a cell destined to produce theirmuscles. How will cell respiration be affected? What symptoms will be observed? What will be observedduring mild exercise? For more information, perform anInternet search using "mitochondrial cytochrome bdeficiency" as the search terms
Case 3 Thiamine deficiency
Thiamine (vitamin B1) is an important cofactor in one ofthe reactions in the Krebs cycle, and also the reaction thatconverts pyruvate to acetyl CoA. It is normally found in the diet in yeast, pork, legumes, cereal grains, rice. It maybecome deficient during malnutrition or conditions that cause malnutrition such as alcoholism, HIV, and anorexianervosa. How will cell respiration be affected? Whatsymptoms will be observed? For more information,perform an Internet search using "thiamine deficiency" as the search terms.
Case 4 Electron transport chain inhibitors such as rotenone,antimycin, cyanide
These inhibitors block one of the steps in the electrontransport system.How will cell respiration be affected? What symptoms will be observed? For more information, perform anInternet search using "rotenone, antimycin, and cyanide"as search terms.
Case 5 Uncouplers such as 2, 4 Dinitrophenol
An uncoupler allows hydrogen ions to leak back acrossthe membrane. It uncouples the process of protonpumping with ATP production. How will cell respirationbe affected? What symptoms will be observed? This drugwas used in the 1930s as a weight-loss drug, but wasbanned in 1938 because of incidences of death. Whywould weight loss occur? Why did some patients die?
For more information, perform an Internet search using"uncouplers" as the search term.
Case 6 Oligomycin
This drug is a direct inhibitor of ATP synthase in theelectron transport system. How will cell respiration beaffected? What symptoms will be observed?For more information, perform an Internet search using"oligomycin" as the search term.