Oxidative Phosphorylation & glycolysis Flashcards
how is first step of oxidative phosphorylation started
passing 2 electrons to FMN (riboflavin aka vitamin b2) this forms NAD+ as a product
what is the result of 2 electrons being delivered to iron -sulfer center and Fe3+ converts into Fe2+
4 protons are pumped into the intermembrane space (mitosol)
where does electron transport chain occur
occurs in inner mitochondrial membrane
explain electron transport chain
NADH donates electrons to the chain, as it progresses, reduction potentials increase until oxygen, which has highest reduction potential, receives the electrons.
Complex I of electron transport chain
NADH-CoQ Oxidoreductase. Uses an iron-sulfur cluster to
transfer electrons from NADH to flavin mononucleotide (FMN),
and then to CoQ, forming CoQH2. 4 H+ ions are translocated by
Complex I.
Complex II of ETC
Succinate-CoQ Oxidoreductase. Uses an iron-sulfur cluster to
transfer electrons from succinate to FAD, and then to CoQ,
forming CoQH2. No H+ pumping occurs at complex II
-from MNTS; SUCCINATE DH IS JUST A BIFUNCTIONAL ENZYME FROM THE KREBS CYCLE SO IT DOES NOT PUMP PROTONS
Complex III of ETC
CoQH2-Cytochrome C Oxidoreductase. Uses an iron-sulfur cluster
to transfer elcetrons form CoQH2 to heme, forming cytochrome
C as part of the Q cycle. 4 H+ ions are translocated by complex III.
from MNTS - coming from CoQ high energy electrons arrive at C3 which pumps four protons into the mitosol.
Complex IV of ETC
Cytochrome C Oxidase. Uses cytochromes and Cu2+ to transfer
electrons in the form of hydride ions (H-
) from cytochrome c to
oxygen, forming water. 2 H+ ions are translocated by complex IV.
THE FINAL HIGH ENERGY ELECTRON CARRIER IS OXYGEN (2H^+ + 2E^- + 1/2O2- H2O) AND WE PUMP 2 PROTONS
Can NADH cross the inner mitochondrial membrane?
no
on the map what is C3 labeled as?
Cytochrome C reductase
C3 contains cytochromes
From C3 high energy electrons are passed down to cytochrome C, what is the main thermodynamic function of CytoC
act as a slight barrier to electron flow
whats the meaning of Le Châtelier’s Principle and its relation to our lecture
If a stress is applied to a system, the system shifts to relieve that applied stress.
if you have a lot of products the reverse reaction will become thermodynamically favorable might even reverse
what is considered the “waterfall step” of Ox/Phos
strongly exergonic (release energy)
what is Exergonic Rxns
Release energy; DeltaG is negative.
what are Endergonic Rxns
Require energy; DeltaG is positive.
what does cyanide do
binds to the Fe3+ of heme in cytochrome C preventing electron transport to C4
stopping cytochrome C causes massive electron backup
cyanide can only bind to Fe3+
true
hemoglobin contains Fe2+
true
how do we treat massive electron backup?
IV NaNO2 or inhaled Amyl Nitrite
think Gibbs free energy
if deltaG is negative we go?
forward
think Gibbs free energy
if deltaG is positive we go?
backward
the energy released when the electron binds with a new carrier is harnessed to pump protons towards or against their concentration gradient?
AGAINST
how is the flow of protons down the ATP synthase favored
both enthalpically and entropically
what are some transporters
adenine nucleotide translocase (antiporter)
phosphate translocase (symporter)
