ETC

Question 0

Myoclonic Epilepsy & Ragged-Red Fibre (MERRF) disease

Answer 0

tRNA for Lysine mutation; clumps of mitochondria; Sx: uncontrollable muscle jerking (late childhood to adult); enlarged mitochondria in muscle; ragged red fibres in muscle; lactic acidosis; progressive dementia & cardiac problems

Question 1

Leber Heriditary Optic Neuropathy (LHON)

Answer 1

NADH dehydrogenase deficiency; Bilateral loss of vision; eyes have high E demand & depends almost entirely on oxidative phosphorylation

Question 2

Mitochondrial Encephalopathy, Lactic Acidosis & Stroke (MELAS)-like episodes

Answer 2

tRNA for LEU mutation; Sx: onset 5-15 yrs; progressive neurodegenerative disease characterized by stroke-like episodes; vomitting, tiredness, muscle weakness, repeated strokes lead to blindness, brain damage, dementia, loss of muscle control

Question 3

Aminoglycoside-induced deafness

Answer 3

12s rRNA mutation; increases binding of aminoglyosides including streptomycin & gentamycin; results in loss of translation of ATP synthase; cochlea has high E demand