Exam 2 Lecture 22 PP Pathway Flashcards
if we have G6P and the enzyme G6P isomerase is working on it, this means the pathway desired is _?
glycolysis or gluconeogenesis
if we have G6P and the enzyme phosphoglucomutase is working on it, this means that the pathway desired is _?
store or breakdown glucose from/to glycogen
the _ phase makes NADPH
oxidative phase
what is the 1st of the 3 reactions for making NADPH
glucose-6-phosphate dehydrogenase oxidizes G6P to form a lactone as well as reduces NADP+ to form NADPH
what is the 2nd of the 3 reactions for making NADPH
lactonase (a hydrolase) opens the ring by adding water
what is the 3rd of the 3 reactions for making NADPH
6-Phosphogluconate dehydrogenase catalyzes the oxidative decarboxylation of 6-phosphogluconate to form ribose 5-phosphate and reduces NADP+ to form NADPH
what is the rate limiting step of phase 1 of PPP
glucose 6-phosphate dehydrogenase
NAD+ is primarily used for
catabolism (oxidative pathway) uses dehydrogenases; e- transport and OxPhos
NADP+ is primarily used for
anabolism (reductive pathway) uses reductases; trying to build NADP+ up for PPP
what are the 2 reasons we need NADPH?
- biosynthetic; synthesis of monomers
2. reducing power of NADPH for detoxification; primarily glutathione (RBCs)
what are some biosynthesis of monomers that require NADPH?
- FA syn
- Cholesterol syn
- Neurotransmitter syn
- Nucleotide syn
what are the tissues with active PPPs?
- adrenal gland, testes, ovary (steroid syn)
- liver, adipose tissue, mammary gland (FA syn)
- liver also cholesterol syn
in the tripeptide glutathione, the gamma linkage is unique as it links the _
oxygen in the side chain of glutamate instead the oxygen in the backbone
what are the 3 options for glutathione redox chemistry?
- interactions with proteins (no enzyme needed) ie disulfide bonds
- inactivation of peroxides (enzyme glutathione peroxidase) ie ROS
- regeneration of reduced glutathione (uses NADPH to make NADP+ = substrate for PPP)
what happens when NADPH is under produced?
G6-phopsphate dehydrogenase deficiency = death of RBCs
what are they types of erythrocyte diseases?
issues with Hb, membrane/cytoskeleton defects, and metabolic errors