5. Mitochondria Flashcards
(24 cards)
what is the major protein in the outer membrane
porin
what is the function of porin
forms large aqueous channels through the outer membrane
what word describes the structure of the inner membrane?
what is an advantage of this?
cristae - many foldings
increases surface area
what is the effect of cardiolipin in the inner membrane
makes it impermeable to most small ions
which membrane is the energy transducing membrane
the inner membrane
what are the three major membrane complexes in the inner membrane
1) components of the electron transport chain
2) ATP Synthase
3) transporters
what are the function of transporters in the inner membrane
they move metabolites in and out of the matrix
what two processes occur in the matrix
1) Krebs cycle
2) fatty acid oxidation
what is substrate level phosphorylation
creates ATP
ADP gains a phosphate from a substrate= ATP
where does glycolysis occur
in the cytosol
what does glycolysis do
releases the small amounts of energy stored in glucose
most energy remains in the pyruvate
what happens to the pyruvate following glycolysis
enters the mitochondrion Krebs cycle (in the matrix)
what are the two electron carriers
NAD & FAD
what do NAD and FAD do?
they transport electrons from the Krebs cycle to the electron transport chain
what occurs in the electron transport chain
- pumps hydrogen ions across the inner membrane to generate an ion gradient
- ATP synthase uses this ion gradient to generate ATP
what is pyruvate converted into in the Krebs cycle, what is lost?
acetyl CoA
- loss of CO2
how does cyanide affect the mitochondria
blocks the electron transport chain
how does 2,4 dinitrophenol affect the mitochondria
makes the membrane leaky to hydrogen ions- so a gradient cannot be generated
what is brown fat
a specialised type of adipose tissue with specialised mitochondria
what is the function of brown fat
produces heat
what does thermogenin do in brown fat mitochondria
functions as a H+ channel in the inner membrane, meaning that H+ ions pumped in the electron transport chain leak back and do not pass through ATP synthase
so the energy released from the electron transport chain is released as heat (no ATP is generated)
what does MERRF stand for
myoclonic epilepsy and ragged-red fibre disease
what occurs in patients with MERRF
affects muscles
causes epilepsy and weakness
what causes MERRF
a mutation affecting tRNA Lys gene
