Pentose Phosphate Pathway Flashcards
What important anabolic starting materials/reducing agents are products of the PPP?
NADPH and Ribose-5-phosphate
The NADPH produced in the PPP plays a key role in ________
The NADPH produced in the PPP plays a key role in reducing oxidative damage by ROS in cells, as well as maintaining HbA in the Fe2+ state in red cells.
Descrive the Oxidative phase of the pentosephosphate pathway:
• The three reactions of the oxidativephase include two oxidations, which produce NADPH.
• The pentose phosphate pathwayprimarily generates NADPH forreductive biosynthesis and ribose-5-phosphate for nucleotide biosynthesis.
Draw the R and P for the rxns in the oxidative phase of the pentosephosphate pathway
The oxidative phase of the PPP generates _________________.
The oxidative phase of the PPP generates 2 mol NADPH and 1 mol CO2 per mol glucose.
Draw the G-‐6-‐P DH mechanism
Draw the 6-‐PG DH mechanism
Yet another example of C-‐C bond cleavage using an e-‐ source (-‐COO-‐) to an e-‐sink (carbonyl)…
The reaction sequence of the nonoxidative branch converts ________________ to _______________.
The reaction sequence of the nonoxidative branch converts 3 five-carbon sugar phosphates to 2 six-carbon sugar phosphates and 1 three-carbon sugar phosphate.
The hexose phosphates formed can be catabolized either by ________________ or _____________.
The hexose phosphates formed can be catabolized eitherby recycling through the pentose phosphate pathway or by glycolysis
Three enzymes involved are:
phosphopentose epimerase
transketolase
transaldolase
Ru5P, Xu5P, and R5P are isomers, related by ________ or __________.
Ru5P, Xu5P, and R5P are isomers, related by epimerization orisomerization
Two Xu5P and one
R5P are converted to _______and _______ in a series of three C-‐C bond rearrangements. These reactions are catalyzed by ______ and
________.
Two Xu5P and one
R5P are converted to two F6P and one
GAP in a series of three C-C bond rearrangements. These reactions are catalyzed by transketolase and transaldolase
Transketolase requires a ___________ cofactor to transfer its 2-carbon unit as an activated aldehyde.
Transketolase requires a TPP cofactor to transfer its 2-carbon unit as an activated aldehyde.
Draw the Transketolase mechanism
Draw the Transaldolase mechanism
Draw the Transaldolase mechanism
Give an overview of the Transaldolase mechanism and Transketolase mechanism
Give and overview of the PPP
