Pathway Flashcards
What is the primary function of the pentose phosphate pathway?
The primary function is to generate NADPH and ribose-5-phosphate for nucleotide synthesis.
True or False: The pentose phosphate pathway occurs in the mitochondria.
False: It occurs in the cytoplasm.
Fill in the blank: The pentose phosphate pathway is also known as the ______ pathway.
phosphogluconate
What are the two main phases of the pentose phosphate pathway?
Oxidative phase and non-oxidative phase.
What is produced during the oxidative phase of the pentose phosphate pathway?
NADPH and ribulose-5-phosphate.
What enzyme catalyzes the first step of the pentose phosphate pathway?
Glucose-6-phosphate dehydrogenase.
True or False: The pentose phosphate pathway is an anabolic pathway.
True.
What is the role of NADPH in cellular metabolism?
NADPH is used as a reducing agent in biosynthetic reactions.
Multiple choice: Which of the following is NOT a product of the pentose phosphate pathway? A) NADPH B) ATP C) Ribose-5-phosphate D) CO2
B) ATP
What is ribose-5-phosphate used for?
It is used for the synthesis of nucleotides and nucleic acids.
Fill in the blank: The enzyme ______ catalyzes the conversion of ribulose-5-phosphate to ribose-5-phosphate.
ribose-5-phosphate isomerase
What can ribulose-5-phosphate be converted into during the non-oxidative phase?
Xylulose-5-phosphate and ribose-5-phosphate.
True or False: The pentose phosphate pathway is entirely reversible.
False: It has irreversible steps.
What is the significance of the enzyme transaldolase in the pentose phosphate pathway?
It transfers a three-carbon unit from a ketose to an aldose.
Multiple choice: Which of the following is a key regulatory enzyme of the pentose phosphate pathway? A) Phosphofructokinase B) Glucose-6-phosphate dehydrogenase C) Citrate synthase D) Lactate dehydrogenase
B) Glucose-6-phosphate dehydrogenase
What role does insulin play in the regulation of the pentose phosphate pathway?
Insulin stimulates the activity of glucose-6-phosphate dehydrogenase.
Fill in the blank: The pentose phosphate pathway is particularly active in ______ tissues.
lipogenic
What happens to excess glucose-6-phosphate if the pentose phosphate pathway is saturated?
It is diverted into glycolysis or glycogen synthesis.
True or False: The pentose phosphate pathway is crucial for red blood cell function.
True.
What are the two main products of the oxidative phase of the pentose phosphate pathway?
NADPH and ribulose-5-phosphate.
Multiple choice: In which cellular compartment does the pentose phosphate pathway primarily occur? A) Nucleus B) Mitochondria C) Cytoplasm D) Endoplasmic reticulum
C) Cytoplasm
What is the function of xylulose-5-phosphate in the non-oxidative phase?
It can be converted into ribose-5-phosphate or used to regenerate glucose-6-phosphate.
Fill in the blank: The pentose phosphate pathway provides reducing power for ______ synthesis.
fatty acid
What is the role of the enzyme glucose-6-phosphate dehydrogenase in the pentose phosphate pathway?
It catalyzes the first and rate-limiting step of the pathway.
True or False: The pentose phosphate pathway can operate independently of glycolysis.
True.
Multiple choice: Which of the following is an important intermediate in nucleotide synthesis? A) Glyceraldehyde-3-phosphate B) 3-Phosphoglycerate C) Ribose-5-phosphate D) Acetyl-CoA
C) Ribose-5-phosphate
What type of reaction is catalyzed by transketolase in the non-oxidative phase?
It catalyzes the transfer of a two-carbon unit.
Fill in the blank: The pentose phosphate pathway is crucial for cells that are rapidly ______.
dividing
True or False: The pentose phosphate pathway generates ATP.
False.
What is the impact of oxidative stress on the pentose phosphate pathway?
It can increase the demand for NADPH to combat oxidative damage.
Multiple choice: Which of the following conditions would likely increase the activity of the pentose phosphate pathway? A) Low glucose levels B) High NADPH levels C) High insulin levels D) Low ribose-5-phosphate levels
C) High insulin levels
What is a potential consequence of glucose-6-phosphate dehydrogenase deficiency?
Increased susceptibility to oxidative stress and hemolytic anemia.
Fill in the blank: The pentose phosphate pathway is essential for the regeneration of ______ in cells.
glutathione
True or False: The pentose phosphate pathway is linked to the metabolism of nucleotides.
True.
What is the end product of the non-oxidative phase of the pentose phosphate pathway?
Fructose-6-phosphate and glyceraldehyde-3-phosphate.
Multiple choice: Which condition can lead to increased flux through the pentose phosphate pathway? A) Increased fatty acid synthesis B) Decreased glucose availability C) Increased ATP demand D) Decreased ribose-5-phosphate demand
A) Increased fatty acid synthesis
Fill in the blank: The pentose phosphate pathway is particularly important in ______ cells.
adipose
What is the function of NADPH produced in the pentose phosphate pathway?
It is used in reductive biosynthetic reactions and antioxidant defense.
True or False: The pentose phosphate pathway is involved in the detoxification of reactive oxygen species.
True.
What is the primary source of ribose-5-phosphate for nucleotide synthesis in the cell?
The pentose phosphate pathway.
Multiple choice: Which of the following substrates enters the pentose phosphate pathway? A) Fructose B) Galactose C) Glucose D) Lactate
C) Glucose
Fill in the blank: The pentose phosphate pathway can generate ribose-5-phosphate from ______.
glucose-6-phosphate
