Mitochondria Flashcards
What are the compartments of the mitochondria?
- Outer membrane.
- Inner membrane (Iamellar or tubular cristae).
- Inner membrane space.
- Matrix.
What is the protein/lipid ratio of the outer membrane of the mitochondria?
1:1
What are porins?
Porins are proteins that cross the mitochondrial membrane and act as pores. They are non-selective permeable.
How are polypeptides transported across the outer membrane of the mitochondria?
Via translocons (TOMs)
What’s the protein/lipid ratio in the inner membrane of the mitochondria?
4:1
Which lipid contributes to about 20% of all lipid composition of the inner membrane of the mitochondria?
Cardiolipin
How are polypeptides transported across the inner membrane of the mitochondria?
Via translocons (TIMs)
How are molecules transported out and in of the mitochondria?
Multiple transport proteins (fully controlled transport).
What does the matrix of the mitochondria contain?
- mtDNA, mtRNAs, mt-ribosomes.
- Krebs cycle enzymes.
- Fatty acid beta-oxidation enzymes.
- Calcium Phosphate deposits (dense bodies)
Whats the main function of the mitochondria?
ATP production
What are some functions of the mitochondria besides ATP production?
- Beta-oxidation of short and medium-chain fatty acids.
- Participation in steroid hormone synthesis.
- Storage of calcium ions.
- Involvement in apoptosis (in brown adipose tissue cells)
- Generation of heat.
What is so special with mitochondria compared to other cell organelles?
It possesses a complete genetic apparatus (ribosomes, DNA, mRNA, tRNA and enzymes nessesary.)
How many rRNA molecules, tRNA molecules and Mitochondrial inner membrane proteins does the mitochondrial DNA encode for?
2 rRNA molecules
22 tRNA molecules
13 mitochondrial inner membrane proteins.
What does it mean that the mitochondria are semiautonomous?
Some proteins are encoded and synthesized inside and by the mitochondria itself and some are synthesised in the nucleus of the cell and transported to the mitochondria. Hence semiautonomous.
What have mitochondria evolved from according to the endosymbiotic theory?
Primitive bacteria capable of oxidative phosphorylation.