Flashcards in Mitochondria Deck (40):
What did mt. descend from?
Do mt have their own genome?
How many mt proteins have been detected?
670 are imported and 13 are made from the mitochondrial genome
How many proteins does the mt genome encode for?
How many membranes does a mt have?
What type of bacteria did mt. descend from?
What is contained within the mt.intermembrane space?
What is contained within mt. matrix?
TCA enzymes, PDH complex, beta ox enzymes, DNA, RNA, ribosomes, ATP,ADP,Pi, ions, etc.
What controls ATP flux in mitochondria?
Cristae contacts with inner membrane
Describe a mt. under active respiration.
Condensed matrix, expanded intermembrane space, proton pumping into intermembrane spacecauses water to follow and swells membrane
What protein controls contact of cristae with mt. inner membrane?
Mitofilin-this is a test question almost 100% sure
What are some apoptotic mitochondrial signals?
Bad, Bix, Bax, etc. causes mt. membrane to become leaky and form pores that cause cyt-c to leak and couple with Apaf-1 which results in a caspase cascade and cell death
What structure does a porin have? What is the largest wt. molecule that can pass?
Beta barrel, 5kDa
What is cardiolipin formed from?
Glycerol with 2 FA
What portion of cardiolipin associates with mt. inner membrane?
If FA is not saturated then what can this cause?
Cardiomyopathy, barth syndrome
Describe a mitochondrial carrier protein
Can carrier lots of small molecules, has structure with 6 transmembrane helices, antiporters , alternate conformations based on salt bridgeskinks formed by proline residues in active site, highly conserved structure
What anion can damage almost any intracellular product? What reduces it?
Superoxide; superoxide dismutase
What can convert hydrogen peroxide to oxygen and water.
What reduces hydroxyradical?
Vit C, Vit E
How many e- does it take to get from oxygen to water?
What proteins are found in the apoptisome
Cytacrome-C APAF-1 and Capase-9
Mitochondrial functions include what?
TCA cycle, respiration, fatty beta oxidation, ammonia elimination via urea cycle, heme biosynthesis, protection against oxidative stress, RNA/DNA/protein biosynthesis, Mt biogenesis, molecular transport, calcium uptake/release
What does the inner membrane hold?
inner membrane holds ETC and ATP synthase as well as set of carrier proteins required for exchange metabolites
Describe active respiration wrt to ADP and what happens to the mitochondria?
-oxygen concentration drops rapidly until ADP runs out
-Mt changes appearance=>
Low [ADP]=> moves from condensed to expanded (orthodox)
High [ADP]=> moves from orthodox to condensed
What protein in the Mt has been linking to cristae morphology and is part of the Mt inner membrane organizing system?
Describe how Mt is important in apoptosis
B, B, B gives a pro-apoptotic signal that causes Mt to become leaky and release cytochrome c into the cytosol
-cytochrome c unites with Apaf-1 to recruit caspase 9 which form the apoptosome that triggers a caspase cascade for cell death
What are caspases?
cysteine proteases that must be activated
What is the protein that is significant in the outer membrane of the Mt?
What is the unique phospholipid in the inner membrane? What are the results if the protein is disrupted?
cardiolipin => Barth syndrome=> defective Mt, cardiomyopathy, muscle weakness
What can move across the inner membrane easy?
water, oxygen, CO2
ADP, ATP, phosphate, pyruvate, and other AA need special transporters are what?
What helps to stabilize the different conformations of the Mt carriers?
charge pairs at the matrix membrane surface shift during the transport cycle
What do diseases of Mt origin result in?
production of ROS
What is the goal of respiration?
reduce oxygen to water and in the process to capture energy of electrons removed from pyruvate
What happens to if one electron is added to oxygen? If the enzyme to eliminate this is not present, what will occur?
oxidative stress linked to alzheimers, parkinsons, aging
What occurs or is found in the Mt matrix?
1. pyruvate DH complex
2. citric acid cycle enzymes
3. fatty acid oxidation enzymes
4. AA oxidation enzymes
As respiration increases, what happens to the christae in the IM space? What protein regulates this?
it increases its openness regulated by mitofilin
ROS are needed for some of the proper insulin signaling. What will occur if this does not happen?
No ROS=> type II diabetes