electron transport chain

what is the electron transport chain?

the process by which electrons are passed from one carrier to another. it occurs in the inner mitochondrial membrane

here, there are 4 membrane bound protein complexes & 2 electron carriers

what are the NADH & FADH used for in the ETC?

they’re used to generate more ATP

what happens at the first carrier?

NADH delivers 2 electrons it’s carried from glycolysis, the link reaction, or the Krebs Cycle. this results in energy being transferred to the ETC and the NADH converts back to NAD.

what do the electrons power?

the electrons power the pumping of hydrogen ions (H+) or protons, across the matric to the intermembrane space.

H+ has to be pumped across the membrane cuz the membrane is impermeable to them & they’re moving against their concentration gradient

what happens to the electrons?

they’re pumped along the ETC, and pump more H+ as they go. the electrons also lose energy as they go

where does the FADH deliver their electrons?

FADH delivers their 2 electrons to the 2nd carrier/protein complex. this means that fewer protons are pumped. FADH gets converted back to FAD

what causes a proton gradient to be established in the intermembrane space?

the space between the inner & outer membrane is small & narrow, and protons cannot diffuse across membranes by themselves

where is the higher & lower concentration>

the proton gradient is across the inner membrane, and the high concentration is on the intermembrane space & the low concentration is on the matrix side of membrane

what is the gradient important for?

it’s important for producing the remaining of the ATP.