Mitochondria

endosymbiotic theory - mitochondria

circular genome, double membrane, similar size, binary fission

mitochondria structure

inner and outer membrane

matrix, intermembrane space, F0 and F1 complex proteins

inner membrane - 3 types of membrane complexes

ETC, ATP synthase, specific metabolite transporters

inner membrane - cristae

increases surface area, energy transducing membrane, impermeable to most small ions

NAD+

electron carrier, accepts high energy electrons from organic molecules, donates electrons to ETC, nicotinamide region can accept 2H from food

glycolysis

breakdown of 6C glucose to 2x 3C pyruvate, substrate level phoshorylation to produce ATP, high energy electrons used to generate NADH

link reaction

pyruvate transported to mitochondrial matrix - decomposed from 3C to 2C acetyl CoA - produces CO2 and NADH

krebs cycle

acetyl coA + oxoloacetate = citrate - high energy electrons passed onto NAD+ and FAD - FAD accepts electrons of slightly lower energy - small amount of ATP produced

ETC main steps

high energy electrons passed onto chain - generates energy through redox reactions - electrons passed onto O2 to generate H2O - energy used to pump H+ into intermembrane space - ATP synthase pumps H+ down gradient into matrix

how are electrons passed along ETC

each component is more electronegative than the last - first molecule is a flavoprotein, then iron-sulphur, then ubiquinone, then a series of cytochromes

where does FADH2 transfer electrons

directly to ubiquinone

F0

H+ channel

F1

site of ATP synthesis

ATP synthase

movement of H+ through F0 causes rotation of rotor and central stalk - forces sequential conformational change in central stalk and f1 - provides energy for atp synthesis

cyanide

prevents passage of electrons from cytochromes and blocks ETC

DNP

makes inner membrane leaky to H+ so gradient can't be established - ETC works but energy is released as heat