pentose phosphate pathway Flashcards
where does the pentose phosphate pathway occur?
in the cytoplasm of all cells
what is the key enzyme of PP pathway?
glucose-6-phosphate dehydrogenase
what are the 2 phases of PP pathway?
oxidative- production of NADPH; irreversible
non-oxidative- interconversion of sugars; reversible
what are the 4 steps of the PP pathway?
Dehydrogenation- of G-6-P
Hydrolysis- of phosphogluconolactone
Oxidative decarboxylation- produces ribulose-5-phosphate
Isomerization- ribose-5-phosphate
what are the reactants of glucose-6-phosphate dehydrogenase?
G-6-P
NADP+
what are the products of glucose-6-phosphate dehydrogenase/ dehydrogenation?
NADPH
6-phosphogluconolactone
what does oxidative decarboxylation produce?
ribulose-5-phosphate
in the isomerization step of PP pathway what is produced?
ribose-5-phosphate
NADPH is an electron donor during which processes?
reductive biosynthesis
respiratory burst
detoxification
regeneration of antioxidants (free radical elimination)
anything that consumes NADPH and ribose stimulates?
pentose phosphate pathway!
building FA
building cholesterol
building steroid hormones
building bile salts
all these processes require electrons from?
NADPH
NADPH is an electron donor when toxins become water soluble for excretion by adding electrons and oxygen. this process is called?
P450 monooxygenase system
aka cytochrome P450 monooxygenase system
when white blood cells take in more oxygen its called
respiratory bursts
creating harsh chemistry to kill bad guys by using
electrons from NADPH
what produces hydrogen peroxide?
superoxide dismutase
superoxide dismutase is used to create reactive species to destroy?
bacteria, viruses and other non-self
what is the enzyme that makes hypochlorous acid from H2O2?
myeloperoxidase- even more productive at killing bad stuff
what is a substance that inhibits oxidation and is capable of counteracting the damaging effects of oxidation in body tissue?
antioxidant
what do free radicals and reactive species attack?
polyunsaturated fat in phospholipids
protein in cells
nucleic acids in DNA
when we add electrons from NADPH to regenerate antioxidants so they can keep protecting the body from free radicals?
antioxidant regeneration
antioxidants need to be given an electron to restore their?
reducing power
what is the process by which electronically excited molecules are inactivated?
quenching- antioxidant giving an electron to the free radical/ reactive oxygen species
when free radicals are quenched, antioxidants get ________
oxidized
when antioxidants are regenerated, they are being ________
reduced
