Pentose Phosphate Pathway Flashcards
What are three requirements for NADPH?
Required for fatty acid synthesis in the liver, adipose tissue, and lactating mammary gland
Required for synthesis of cholesterol and steroid hormones in liver, adrenal glands, and gonads
Regenerates reduced glutathione to counter damage from oxygen radicals
What are two uses for ribose 5-phosphate?
Required to make DNA, RNA, NADH, FADH2, and CoA
Used in rapidly diving cells, including tumors
What two things does the pentose phosphate pathway produce?
NADPH
Ribose-5-phosphate
What are the two phases of the pentose phosphate pathway?
Oxidative - produces NADPH
Non-oxidative - not making NADPH
What is the rate-limiting step of the pentose phosphate pathway?
Glucose 6-phosphate dehydrogenase
What inhibits G6P dehydrogenase?
NADPH
What two enzymes produce NADPH in the pentose phosphate pathway?
Glucose 6-Phosphate dehydrogenase
6-phosphogluconate dehydrogenase
What is the role of the non oxidative pathway?
Converts six 5-carbon sugar phosphates to five 6-carbon sugar phosphates
What two enzymes are utilized in the nonoxidative pathway?
Transaldolase
Transketolase
What is required for the activity of transketolase?
Thiamine Pyrophosphate (TPP)
What is the cause of Wernicke-Korsakoff syndrome?
Severe thiamine deficiency
Chronic, heavy alcohol consumption interferes with intestinal absorption of thiamine
What are the symptoms of WK syndrome?
Memory Loss
Inability to make new memories
Mental confusion
Vision issues
Partial paralysis
What is the consequence of a mutation in transketolase?
Lower affinity of enzyme for TPP
Higher sensitivity for thiamine deficiency
PPP slows down
What pathway is activated when the cell has a high demand for ribose?
PPP-oxidative pathway
What pathway is activated when the cell has a high demand for ribose and NADPH?
PPP-oxidative pathway
