Mitochondria Flashcards
How many mitochondria are in a cell?
100-100 dependant on cell type, maintained by division
What is the DNA structure?
2-10 heteroplasmic copies of maternally inherited dsDNA
17kb,
37 genes encoding proteins, tRNA, polymerase
Are mitochondria autonomous?
No, they uptake unfolded proteins using N-terminal basic signal sequences through junction proteins spanning both membranes, using H+ gradient
What are the characteristics of diseases associated with mitochondrial?
Rare and fatal
In ATP-demanding tissues
What are the mitochondrial diseases?
Lebers hereditary optic neuropathy
Kearn-Rayes syndrome
Ragged muscle fibres
What is the cause of Lebers hereditary optic neuropathy?
ETC complex 1 mis-sense mutation
What is the casue of Ragged muscle fibre syndrome?
Mutated Lys-tRNA
What does Kearn-Rayes syndrome effect?
eyes and CNS
How are mitochondria implicated in apoptosis?
Intrinsic stimuli release cytochrome C to activate procaspases and apoptosome formation
What are the intrinsic apoptotic stimuli?
Hypoxia
Withdrawal of growth factors
Metabolic stress
DNA damage
How is apoptosis inhibited by viruses?
Mutation of BCL family regulators
What function does E1B-19 adenovirus have on apoptosis?
Complexes to Bax to prevent activation of apoptosis by release of Cytochrome C
