energy transformers food - - - ATP (energy)
mitochondria details of inner membranes
- -inner membrane highly folded
- -large surface area
- -space in center =matrix
Mitochondria outer membrane
- -space between the two membranes
- -about the size of bacteria
- have their don DNA
- the energy currency of the cell
- -debit card-put in money,store it, take out when needed
Energy stored in ATP used for
- -biochemical reactions
ATP phosphates and hydrolysis?
the two outermost phosphates are held to rest of the molecule w/ high energy bonds
Net yield of atp per glucose molecule in aerobic and and anaerobic conditions ?
- -aerobic condition -36atp/glucose
- -O2 picks up eletrons at end of electron chain
- -anaerobic condition 2 Atp/glucose
- -lactic acid is produced by fermentation of glucose
- muscle cell can use lactic acid, but not neurons-brain stops working without O2
- Neurons -lack enzyme for convering pyruvate to lactic acid.
evolutionary origin of mitochondria
- -originated from free-living aerobic bacteria that were engulfed by anaerobic cells
- -ended up living in symbiosis w/ englufing cell
what did the engulfed cell- the are taht ended up being a mitochondria get out of this?
- -nutriants: mitrochondria take nutrients from cytosol and turn them into energy.
what happen 2 billions years ago ?
partnership between a primitive anaerobic eukaryotic predator cell and aerobic bacteria. At that time earth's atmospher started to become rich in oxygen
Mitochondri are mobile and plastic
- -change shape
what do mitrochondria follow when they move?
- they follow microtubuli
- liver cells -1000 mitroch/cell, take up 20% of volume
Metabolic pathways in mitochondria
- -outer membrane-large pores -same composition as cytosol
- -pyruvate +fatty acids from glycolysis pass throught outer membrane
- -inner membrance more selective, but contains transport molecules
Glycolysis happens where?
glycolysis happens in cell's cytosol and the rest of respiration in mitochondria
in matrix of mitochondria
enzymes convert pyruvate + fatty acids into cetyl coa and next acetyl coa goes into citri acid cyle
citric acid cycle generates
- -electrons picked up and carned by NADH and FADH2
- -NADH+ FADH2 are transferred to inner mitochondrial membrance
Electron- transport chain
(oxydative phosphorylation) purpose
purpose generate proton gradient across inner mitochondrial membrance
what happen in electron -transport chain?
- Electrons carried by NADH, FADH2 are passed along 3 main complexes each on has higher affinity for electrons than previous one
- -electrons finally transferred to oxygen ( highest affinity for electrons)
- -transfer of electrons along chain is coupled to proton (H+) movement
- -H+ pumped across inner membrance from matrix to intermembrane space.
Pumping of protons generates
- 1- voltage gradient across inner membrance
- -inside more negative b/c outflow of positive protons
- 2-ph gradient across inner membrance
- -lower ph in intermembrane space
- 1+2 act to pull H+ back into matrix
- now we can use force of proton gradient to drive ATP synthase to generate ATP from food.
Structure of atp synthase Lollipop head
- -f1, projects on matrix side of inner membrance
- -transmembrance H+ carrier =FO
- -long arm=Stator
process of ATP synthase
- protons flow down proton gradient througt FO
- -as subunit in FO bind protons they move results in retation
- -proton gradient converted mechanical energy
- -converted to shaft in center of lollipop head (blue on right)
how many subunits in lollipop head hav binding sites for ADP and how many molecules of ATP per revolution?
- 3, and the changes in protein conformation due to rotation binds p, to ADP.
- 3 molecule of atp per revolution
- -ATP synthase can generate 100 molecules of ATP per second
ATP synthase can run in reverse when?
if atp concertration is hight and proton gradient is low