Oxidative Phosphorylation Flashcards
What is substrate level phosphorylation
Generating small amounts of ATP from glycolysis and the TCA cycle directly
What is oxidative phosphorylation
Generating a larger yield of ATP via high energy electron carriers e.g. NADH, FADH2 via transport along a chain to finally react with oxygen
When is substrate level phosphorylation important
When we need energy rapidly without oxygen
How do we generate ATP during high intensity exercise
Glycolysis occurs rapidly generating lots of pyruvate, which can be converted to lactate to regenerate NAD+ to allow glycolysis to continue so more ATP and NADH can be produced
What does energy production via the ETC rely on
Redox reactions
How is NADH generated in glycolysis and the TCA cycle
Via reduction/ gaining of an electron
Where does oxidative phosphorylation occur
The inner mitochondrial membrane
How many complex proteins are there in the ETC
4
What 3 enzymes are essential in the ETC
Coenzyme Q, Cyt C and ATP synthase
What happens to redox potential/ electron affinity as you move through the protein complexes in the ETC
Increases across 4 complexes
Which molecules are needed to supply the energy needed to start the ETC
NADH and FADH2
Which complex does NADH donate its electron to
Complex 1
Which complex does FADH2 donate its electron to
Complex 2
What happens at the start of the ETC
NADH and FADH donate electrons to protein complexes, leaving H+ ions free
What happens to the electrons donated by NADH and FADH2 in the ETC
Move along the chain from complex to complex until the electrons are accepted by O2 at complex 4
What happens to the free H+ ions as the electrons move down the chain
Transported into the intermembrane space
What is the transfer of H+ ions from the mitochondrial matrix to the intermembrane space called
Chemiosmosis
What does the transfer of H+ ions into the intermembrane space create
A positive chemical gradient , the IMS is more acidic than the Mitochondrial matrix
How does the ETC generate ATP
As it is now more + than - in the IMS, the H+ wants to diffuse back into the mitochondrial matrix via ATP synthase, which results in the generation of ATP
What is hormonal or allosteric regulation of the ETC dependent on
The energy status of the cell
What encourages the electron the electron flow through the chain (ATP production)
High NADH, ADP and Pi
Why does high levels of ADP promote oxidative phosphorylation
Signals that the TCA cycle and glycolysis are occurring rapidly and we need more energy
How many molecules of ATP does one molecule of NADH in the TCA cycle generate
3 ATP molecules
