What is most energy harvested as during the breakdown of food?
Electrons in NADH and FADH2.
What is Redox Potential?
The different affinity of atoms to incorporate or release electrons into/from their outer shell.
What do differences in redox potential provide?
Energy Source
What does having a negative or positive redox potential mean?
Negative = lot of free energy
Positive = little free energy
What is the Electron Transport Chain in simple terms?
Series of redox reactions in the inner membrane of the mitochondria
What does the ETC drive?
Directional movement of protons into the inner membrane space.
Redox groups are ‘coloured’ they have distinct spectra, how do they differ? What can we follow by measuring this spectra?
Differ in the oxidised and reduced states,
We can follow the change in redox state of each component.
What is the only ETC component that doesnt contain a proton pump?
Succinate-Q reductase
State the 4 most common redox groups.
Flavins, Quinones, Heme group, Iron-sulfur clusters
What are free radicals?
Unpaired electrons that are highly reactive and can destroy other molecules.
How do enzyme complexes in the ETC safeguard their environment from radicals?
Holding them deep inside their structure.
What is the Q cycle?
A repetitive cycle in which a radical intermediate is held inside the enzyme to enable electron transfer from reduced ubiquinone to cytochrome c.
Differences between chloroplasts and mitochondria
Size and sub-compartmental structures
Similarities between mitochondria and chloroplasts
Mechanisms and their orientation with respect to stroma/matrix; electron transport chain, chemiosmosis
What do structural proteins do?
Determine cell shape and contribute to the extracellular environment.
Structural proteins can form molecular machines by self-assembly. What are some examples of these molecular machines?
Microfilaments, intermediate filaments, microtubules
What do scaffold proteins do?
Bring proteins together into an ordered complex; allows increased efficiency than if the proteins were not assembled together.
What are regulatory proteins?
Signals, sensors and switches that control cell function by altering the function of other proteins.
The higher the concentration of molecules …
The greater the frequency of collision.
Molecules that exhibit molecular complementarity can form multiple ____________ interactions at close range.
Non-covalent
What does binding depend on?
Geometry of two binding partners
The higher the affinity of two molecules …
The better the ‘molecular fit’ between them, the more non covalent interactions can form and the more tightly they bind.
What happens to cAMP-dependent protein kinase A when cAMP levels rise?
Conformationl change of R subunits, so weakens association between R2 and C subunits. C subunits fall off and the catalytic activity of the C subunit is turned on- kinase can now phosphorylate its targets
What is the dissociation constant?
Way to quantify and measure binding. Calculated from the concentrations of the three components when they are at equilibrium.
