Final Exam (CoQ10) Flashcards
*How many isoprene units attached to a benzene ring does CoQ10 have?
10biquinone
50% of the bodys CoQ is found where?
Inner mitochondrial membrane
Which form of CoQ is fully oxidized and has two double bonded oxygens?
Ubiquinone
Which form of CoQ is fully reduced with two OH groups?
Ubiquinol
What three enzymes are responsible for keeping CoQ reduced in cells/plasma?
- NADH cytochrome reductase
- NADH/NADPH oxidoreductase
- NADPH CoQ reductase
*In the mitochondria which two enzymes are there… along with what part of the electron transport chain are they a part of?
- NADH dehydrogenase (complex 1)
- succinate dehydrogenase (complex 2)
Ubiquinone/Ubiquinol are better absorbed in what kind of form?
Oil based form
*Is solubilized Ubiquinone/Ubiquinol better absorbed in the human?
Ubiquinol
*As the ingested dose increases, what happens to the absorption rate?
LOWER % is absorbed
High doses of what vitamin can interfere with CoQ absorption?
Vitamin E
*Tissues synthesize CoQ from what two things?
- Farnesyl diphosphate (FPP
- Tyrosine
*CoQ is synthesized intracelllularly using what as the fundamental building block?
- Mevalonate
What are the 3 essential cofactors for CoQ biosynthesis?
- B6
- Iron
- Mg
How many enzymatic steps are needed to make CoQ ?
17 enzymatic steps
*In the mevalonate pathway, what is the rate limiting step? CoQ and cholesterol synthesis also use this enzyme…
HMG-CoA Reductase
*Since CoQ and Cholesterol synthesis use HMG-CoA Reductase, what type of drug can actually inhibit both of these from working?
Statins
When a patient is on statins, what nutrient must they be taking in conjunction with the statin?
CoQ10
Free radicals which are not being scavenged by CoQ are allowed to destroy the mitochondrial membrane, leaking cytochrome C into the cell –> caspase cascade –> apoptosis… what is this disease called?
Rhabdomyolysis
*Which organ is most susceptible to CoQ deficiency due to its high concentration within this organ?
- The heart
- Large number of mitochondria in cardiac muscle which makes sense that the concentration of CoQ is really high here
- CoQ also improves efficiency of energy production in cardiac muscle
CoQ acts as an intermediate step in what pathway? It also provides what qualities intracellularly?
- Electron transport chain
- intracellular antioxidant
What two substances can regenerate CoQ?
- DHLA (Dihydrolipoic Acid)
- Thioredoxin reductase
Where is most of CoQ excreted?
Feces, although some can leave in the urine as well attached to glucuronide…
Does CoQ reduce systolic, diastolic, or both?
BOTH
When ubiquinol is used as an antioxidant, what is it converted into?
Ubisemiquinone
