Oxidation-Reduction Reactions Flashcards
What do metabolic fuels oxidize to?
CO2
What drives ATP synthesis?
Transmembrane proton concentration gradient created by electron transfer from metabolic fuels to molecular carriers to O2.
What types of reactions produce most of the free-energy supplied to living organisms?
Oxidation-reduction reactions where protons are transferred via intermediate carriers.
What are the two most widely used electron carriers?
NAD+ and FAD
What does NAD+ stand for? How many electrons will it accept?
Nicotinamide adenine dinucleotide; 2 electrons
What does FAD stand for? How many electrons will it accept?
Flavin adenine dinucleotide; 1 or 2 electrons
What is the site of reversible reduction (or transfer of hydride ion) on NAD+?
The Nicotinamide portion
How many electrons can NAD+ and NADP+ accept?
2 electrons
Why can FAD accept either 1 or 2 electrons?
It’s conjugated ring system will become a stable semiquinone (1 electron) or hydroquinone (2 electrons)
What is the semiquinone form of FAD+?
FADH
What is the hydroquinone form of FAD+?
FADH2
What kind of reaction do you have if you see either FAD or NAD+?
Oxidation or a reduction
What is the metabolic function of NAD+ and FAD?
They undergo reversible oxidation/reduction reactions and pass electrons to other carriers (thereby being regenerated).
Where do humans get flavin?
In our diet in the form of riboflavin (B6); cannot be synthesized.
What can lead to a deficiency of flavin (or riboflavin)? What symptoms does this cause?
Malnutrition or bizarre diets; inflamed tongue, lesions at the corner of mouth, and dermatitis.
