Cell Integrity Flashcards
Why are fewer ATP molecules produced when FADH2 is reoxidised by the electron transport chain compared with NADH?
Complex I is bypassed and fewer protons are pumped to the inner membrane space
The redox couple NAD+/NADH, has a standard redox potential of -0.32 V. What does this imply?
The redox couple has more reducing power than hydrogen
How do the cristae of the mitochondria facilitate ATP production by oxidative phosphorylation?
The provide a greater surface area for the membrane-bound components of the electron transport chain
The metabolic poison rotenone inhibits the oxygen consumption of mitochondrial suspensions metabolising citrate. However, it has little effect upon the oxygen consumption of a suspension of mitochondria metabolising succinate - why?
Rotonone does not inhibit complex II of the electron transport chain
How does substrate level phosphorylation differ from oxidative phosphorylation?
Oxidative phosphorylation utilises an electron transport chain to drive ATP production
Where does oxidative phosphorylation take place?
In the cristae of the mitochondria
Which co-enzymes are reoxidised by oxygen?
NADH and FADH2
A substrate that can exist in both oxidised and reduced forms?
Redox couple
In an oxygen electrode, what is the resulting current proportional to?
The oxygen concentration
How can we see the effects of various substrates and inhibitors on the electron transport chain?
Prepare a suspension of mitochondria and place it into an oxygen electrode chamber. The oxygen consumption is then monitored
What is the most common cause of a failure of oxidative phosphorylation?
a lack of oxygen
Roughly how many times is an ATP molecule recycled every day?
300
What controls the uptake of oxygen by the mitochondria?
Inorganic phosphate and ADP
What are metabolic poisons?
Molecules that interfere with either the flow of electrons along the ETC or the flow of protons through ATP synthase by definition, interrupt ATP synthesis
What is the effect of DNP on weight loss?
Dinitrophenol can induce weight loss by transporting protons across the mitochondrial membrane, thereby uncoupling oxidative phosphorylation from ATP production and markedly increasing the metabolic rate and body temperature.
