mitochondria Flashcards
(24 cards)
what are mitochondria
energy making centre
membrane- enclosed organelles
what size are mitochondria
1-10um in size
what are the functions of mitochondria
cell signalling
cell differentiation
cell death
control of cell cycle and cell growth
where are mitochondria localised
in all aerobic eukaryotic cells
clustered in regions of greatest metabolic activity- greatest need of ATP
what is the endosymbiotic theory
mitochondria are descended from ancient bacteria which were engulfed by the ancestors of eukaryotic cells more than a billion years ago
what organelles do mitochondria contain
ribosomes
own independent genome (similar to bacteria genome)
the mitochondria is composed of compartments that carry out 3 specialised functions what are some of the structures
granules
ribosomes
cristae
matrix
DNA
inner/outer membrane
inner membrane space
ATP synthase particles
how many mitochondrial proteins do humans and mice have
615- human
940- mice
why do mitochondrial proteins vary
depending on the tissues and species
what is the outer membrane
encloses entire organelle
has protein to phospholipid ratio similar to the plasma membrane
what does the outer membrane do
channels that allow molecules<5000 Da to freely diffuse across the membrane
what does the outer membrane contain
Porins- integral proteins
what is translocase
its an active transport protein that larger proteins can enter the outer membrane through if they have a signalling sequence
when does the outer membrane lead to cell death
when it’s disrupted and permits proteins in the intermembrane space to leak into the cytosol
what is the intermembrane space
space between inner and outer membrane space. same concentrations of small molecules as cytosol
does the intermembrane space have the same or different protein composition to that of cytosol
it differs as active transport is needed
what is one protein that is localised to the intermembrane space
cytochrome- part of the electron transport chain
there are 4 proteins contained in the inner membrane space and what are their functions
perform the redox reactions of oxidative phosphorylation
ATP synthase generates ATP in the matrix
specific transport proteins that regulate metabolic passage into and out of the matrix
protein import machinery
what else is in the inner membrane space
contains more than 100 different polypeptides
what is the phospholipid to protein ratio in the inner membrane
3:1 by weight
what is Cardiolipin and what does it do
contains 4 fatty acids and may help to make the inner membrane impermeable
what do all ions and molecules require in the inner membrane
special membrane transporters to enter and exit the matrix
what is ATP synthase
an enzyme that synthesises ATP from ADP and inorganic phosphate
what does ATP synthase do
