Mitochondrial transport Systems Flashcards
What is the primary function of oxidative phosphorylation?
Reduce molecular oxygen to water using NADH and FADH2 generated by the TCA Cycle.
True or false: The reduction of oxygen to water using NADH and FADH2 is highly endergonic.
False; it is highly exergonic.
What is the collective name for the inner mitochondrial membrane proteins that accomplish the reduction of molecular oxygen by NADH and FADH2?
Electron transport chain
How do cytosolic reducing equivalents get into the the mitochondria?
Either by the malate-aspartate shuttle run in reverse or by the glycerophosphate shuttle
In which part of the cell is most of the ATP generated by the mitochondria used?
Cytosol
How does ATP get out of the mitochondrial matrix?
Via ADP-ATP translocator (adenine nucleotide translocase)
How does ADP-ATP translocator work?
Based on concentration gradient (equilibrium); moves ATP out of the mitochondrial matrix in exchange for ADP from the cytosol.
How does the glycerophosphate shuttle get NADH into the mitochondria?
Takes NADH to FADH2 and moves it across the inner membrane.
What is the structure and mechanism of ADP-ATP Translocator?
Dimer with two identical subunits that exists in two conformations (one with binding site inside inner mitochondrial membrane, one with binding site outside of membrane). ATP and ADP compete for the binding site. Binding the ligand causes a change in conformation; it imports one ADP for each ATP exported out. It is driven by concentration gradient.
Is there a greater chance of ATP being transported into or out of the mitochondria? Why?
Out; it is generated in the mitochondria, and the ADP-ATP Transporter works based on concentration.
From what is ATP synthesized in the mitochondria?
ADP and Pi
How does Pi get into the mitochondria?
Via phosphate carrier
What does a phosphate carrier move across the inner mitochondrial membrane?
Pi and a proton (H+)
What controls the phosphate carrier?
pH (or transmembrane proton gradient)
What provides the thermodynamic driving force for ATP synthesis and motivates the transport of raw materials for the production of ATP (ADP and Pi)?
pH (or transmembrane proton gradient)
