L13 - Oxidative Phosphorylation

Oxidative phosphorylation is how ___ is produced

ATP

Chemiosmotic theory the synthesis of ATP is coupled to

electron transport, energy rich proton gradient, hydrogen ions diffuse back via the ATP synthase complex, energy from proton gradient is used to drive the conversion of ADP to ATP

Experimental design showed that we need ________ for ATP synthesis

e transport

Experimental design showed that uncoupling e transport and atp synthesis showed that electron transport can

occur without atp synthesis by dissipating the proton gradient

At equilibrium of proton gradient, there is no

ATP synthesis

By changing the proton concentration, there is a proton gradient that drives

ATP synthesis even without oxygen consumption. Potential difference drives ATP synthesis.

ATP synthase is F0 membrane embedded in the ___________ and F1 is present in the ____

inner membrane; matrix

______________ has the proton gradient

Intermembrane space

F1 complex has 3 alpha and 3 beta subunits that are arranged

alternating which makes 3 dimers of alpha and betas attached to a gamma shaft

F1 is the site of

atp synthesis

ATP is synthesized at the

interface between those alpha-beta dimers

Alpha-beta dimers do not rotate but they

adopt different conformations as the gamma shaft rotate

Conformation process

ADP + Pi enters alpha beta, gamma shaft rotates 120 degrees, causing a conformational change, ADP+Pi -> ATP, gamma shaft 120 degrees, causing a conformational change, ATP released

______ is the driving force of the rotation of the gamma shaft. Rotation is driven by proton gradient

Fo complex

Fo has a half channel on the _____ side and a half channel on the _____ side

positive; negative

Fo is made up of

an a, b, and c ring (8-15)

C subunits in the c ring formation will rotate as a

unit which allows protons to be released to the negative side from the positive side

C ring is like a

ferris wheel that carries protons

ADP enters the matrix by

adenine nucleotide translocase (antiporter) as ATP exits the matrix

Phosphate groups enters the matrix via the

phosphate translocase (symporter) with H+ protons

Phosphate translocase is/ is not coupled with ATP synthesis

IS NOT even though it transports H+ protons

NADH created in glycolysis needs to be transported from the cytosol to

the mitochondrial matrix

NADH needs to go through electron exchange to enter the mitochondrial matrix:

Oxaloacetate -> Malate which oxidizes NADH, malate is transported to matrix by malate-akg transporter, malate -> oxaloacetate which reduces NAD+ to NADH

glycerol 3-phosphate shuttle is an alternative way of moving

reducing equivalents from the cytosol to the respiratory chain, and operates in skeletal muscles in the brain.

Glycerol 3-phosphate is not as efficient but is

rapid