MBOD Flashcards
(27 cards)
How many mitochondrial genes with known function are transcribed in the mitochondria?
13
What percent of proteins found in the mitochondria are imported?
98%
What do the mitochondrial genes encode?
oxphos subunit proteins
What major protein is located in the outer mitochondrial membrane?
porin, a trimerizable protein
What does porin do?
transports small (<5000Daltons) molecules between cell cytosol and intermembrane space
What is the space between the outer and inner membranes called?
the intermembrane space
What are the invaginations of inner membrane called?
cristae
What connects the cristae to the inner membrane?
mitofilin
What is cytochrome C, where is it located, and what does it do?
a mitochondrial carrier protein located near to the intermembrane space that functions to transport electrons between TM complexes of the inner membrane
What are some proteins located in the inner mitochondrial membrane?
cardiolipin, electron transfer complexes, transporters/carriers
What is cardiolipin?
important inner membrane protein associated with ETC complexes
The inner mitochondrial membrane is permeable to what? impermeable to what?
permeable: H2O, O2, CO2
impermeable: protons, ions
What is the morphology of cristae in a state of active respiration?
condensed
What is the morphology of cristae in state 4 respiration?
condensed
What is the morphology of cristae in state 3/inactive respiration?
expanded
Why is the IM space expanded during active respiration?
it is full of protons (gradient) and thus has brought lots of water with it
What are the main mitochondrial events leading up to apoptosis?
cristae fusion; cytochrome C released into cytosol; apoptosome formed in cytosol
What is mitochondrial uncoupling?
It’s the uncoupling of mitochondria’s joint functions: consume O2 and produce ATP. Can occur when the proton gradient is lost
What are the major mitochondrial metabolic functions?
TCA, ETC, Heme synthesis, DNA/RNA transcription, protein synthesis, ribosome assembly, beta-oxidation, urea cycle (ammonia), transport, Ca2+ uptake/release
What are the 4 major ROS?
- O2 (oxygen)
- O2- (superoxide)
- H2O2 (hydrogen peroxide)
- *OH (hydroxyl radical)
What is the cell’s protection against superoxide?
superoxide dismutase
What is the cell’s protection against hydrogen peroxide?
catalase –> H2O + O2
What is the cell’s protection against hydroxyl free radical?
vitamin C and E
How does hydroxyl radical result?
reaction of Fe2+ with H2O2
