Cellular Respiration Flashcards
Describe the structure of the mitochondria
double membrane
inner membrane folds = cristae
matrix with small circular pieces of mitochondrial DNA
contains over 1000 different types of proteins
What are cristae? What purpose do they serve?
the inner membrane folds of the mitochondria expand the surface area
What is located in the matrix of the mitochondria?
small, circular pieces of mitochondrial DNA
How many proteins are found in the mitochondria?
over a thousand
What proteins does the mitochondrial matrix contain?
free enzymes that function in metabolic pathways (ex. pyruvate oxidation to acetyl-CoA, the CAC, the beta-oxidation of fatty acids)
What do the proteins in the inner mitochondrial membrane and cristae do?
enzymes are embedded there for the ETC and oxidative phosphorylation
What is the typical size of a mitochondria?
0.5-1 um
T or F: mitochondria are static and do not change shape or move
false! they are very dynamic
always moving, changing shape and size
how do mitochondria divide and fuse in relation to the cell they are located in?
independently
What process of cell division is mitochondrial division similar to?
binary fission
What form of mitochondria do some developing cells have?
tubular networks of mitochondria
What kind of cells have restricted space for mitochondria?
muscle fibres
sperm
What are mitochondria often associated with? what does this help with?
often associated with the cytoskeleton to determine their orientation and distribution in different cell types
motor proteins can help them travel up and down microtubules
What is a major distinction between the inner and outer mitochondrial membranes?
inner: selectively permeable membrane which many things require a transporter to pass through
outer: freely permeable to small molecules and some small proteins
What is the IMM most similar to?
bacterial plasma membrane
What is the OMM most similar to?
a membrane that lines the cell walls of some gram negative bacteria
What allows the OMM to be freely permeable?
its wide channels (porins)
What is the protein to lipid ratio of the IMM?
3: 1 protein: lipid
Why are there so many proteins in the IMM?
they are critical for cellular respiration and signalling
What major membrane component does the IMM not contain?
cholesterol
What is cardiolipin? Which mitochondrial membrane contains this and in what quantity?
a unique bacterial membrane phospholipid
inner membrane contains a large quantity
How many proteins are synthesized in the mitochondria? What synthesizes it?
13
its own DNA and its own ribosomes synthesize these
How and where are the other proteins for the mitochondria synthesized?
coded for in nuclear DNA
synthesized on cytosolic ribosomes
imported post-translation with a mitochondrial signal sequence
How do most proteins synthesized outside of the mitochondria enter the mitochondria?
they are translocated across both membranes by translocases