Death Pathways Flashcards
How is a proton gradient generated in the inner mitochondrial membrane?
Electrons from reduced NAD are passed down an electron transport system
What are the electrons oxidised to?
Water
What are the three major complexes in the mitochondria?
NADH dehydrogenase complex
Cytochrome b-c1 complex
Cytochrome oxidase complex
What form is mitochondrial DNA in?
Circular, it has no ends
How are proteins targeted to the mitochondria?
N-terminal uptake targeting or transit sequence.
Entry requires unfolded protein bound to a chaperone.
Energy dependent, sequence is usually cleaved after uptake.
How are proteins emitted into the matrix of the mitochondri?
Membranes must contact and line up, requires a proton gradient
What is Leber’s hereditary optic neuropathy?
Missense mutation in NADH-CoQ reductase leads to the degeneration of the optic nerve and blindness.
What is Kearn-Sayers syndrome?
Large deletions in mitochondrialDNA leads to eye defects and CNS degeneration
What is Ragged muscle fibre syndrome?
Mutations in mtNA decrease mitochondrial translation
How is apoptosis controlled?
Activation of death receptors on the cell surface,
withdrawl of survival factors leading to activation of an intracellular proteolysis syetem mediated by proteases and caspases
What is the BCL-2 family?
Anti-apoptotic found in B-cell lymphomas, block apoptosis
What does adenovirus do in mitochondria?
protein forms complex with Bax family members and surpresses release of cytochrome c via mitochondrial pores
