Sedoheptulose-7-phosphate.
The pentose phosphate pathway converts the six carbon sugar, glucose 6-phosphate, into the five carbon sugar, ribose 5-phosphate, an important component of many biomolecules including ATP, NAD, CoA, DNA and RNA. In addition to serving as the primary source of ribose, the pentose phosphate pathway also serves as the primary source of the cell's supply of NADPH. Differing structurally from NADH by the presence of a single phosphate, NADPH serves a different set of enzymes as coenzyme. NADH drives the electron transport system in energy metabolism, while NADPH is the primary source of reducing equivalents in biosynthesis.
Conceptual Vocabulary for Pentose Phosphate Pathway
Pentose Phosphate Pathway
Each list begins with basic conceptual vocabulary you need to know for MCAT questions and proceeds to advanced terms that might appear in context in MCAT passages. The terms are links to Wikipedia articles.
Nicotinamide adenine dinucleotide phosphate
Nicotinamide adenine dinucleotide phosphate is a cofactor used in anabolic reactions which require it as a reducing agent.
Nicotinamide adenine dinucleotide phosphate is a cofactor used in anabolic reactions which require it as a reducing agent.
Ribose
The simple sugar, ribose, is a component of the ribonucleotides from which RNA is built.
The simple sugar, ribose, is a component of the ribonucleotides from which RNA is built.
Pentose phosphate pathway
The pentose phosphate pathway is a process that serves to generate NADPH and the synthesis of pentose sugars.
The pentose phosphate pathway is a process that serves to generate NADPH and the synthesis of pentose sugars.
Erythrose 4-phosphate
Erythrose 4-phosphate is an intermediate in the pentose phosphate pathway as well as serving as a precursor in the biosynthesis of the aromatic amino acids tyrosine, phenylalanine, and tryptophan.
Erythrose 4-phosphate is an intermediate in the pentose phosphate pathway as well as serving as a precursor in the biosynthesis of the aromatic amino acids tyrosine, phenylalanine, and tryptophan.
Oxidative stress
Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage.
Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage.
Sedoheptulose
The phosphorylated heptose, sedoheptulose 7-phosphate is an intermediate in the pentose phosphate pathway.
The phosphorylated heptose, sedoheptulose 7-phosphate is an intermediate in the pentose phosphate pathway.
Transketolase
In transferring 2-carbon fragments between monosaccharide phosphates, as part of the process of feeding excess sugar phosphates into the main carbohydrate metabolic pathways, the enzyme transketolase connects the pentose phosphate pathway to glycolysis in mammals.
In transferring 2-carbon fragments between monosaccharide phosphates, as part of the process of feeding excess sugar phosphates into the main carbohydrate metabolic pathways, the enzyme transketolase connects the pentose phosphate pathway to glycolysis in mammals.
Transaldolase
In transferring a 3-carbon fragment between monosaccharide phosphates, as part of the process of feeding excess sugar phosphates into the main carbohydrate metabolic pathways, the enzyme transaldolase connects the pentose phosphate pathway to glycolysis in mammals.
In transferring a 3-carbon fragment between monosaccharide phosphates, as part of the process of feeding excess sugar phosphates into the main carbohydrate metabolic pathways, the enzyme transaldolase connects the pentose phosphate pathway to glycolysis in mammals.
Ribulose 5-phosphate
Ribulose 5-phosphate is one of the end products of the pentose phosphate pathway. It is also an intermediate in the Calvin cycle.
Ribulose 5-phosphate is one of the end products of the pentose phosphate pathway. It is also an intermediate in the Calvin cycle.
Glucose-6-phosphate dehydrogenase
Glucose-6-phosphate dehydrogenase is an enzyme in the pentose phosphate pathway converting glucose-6-phosphate into 6-phosphoglucono-delta-lactone.
Glucose-6-phosphate dehydrogenase is an enzyme in the pentose phosphate pathway converting glucose-6-phosphate into 6-phosphoglucono-delta-lactone.
6-phosphogluconolactonase
6-phosphogluconolactonase is an enzyme in the pentose phosphate pathway, converting 6-phosphogluconolactone to 6-phosphogluconate.
6-phosphogluconolactonase is an enzyme in the pentose phosphate pathway, converting 6-phosphogluconolactone to 6-phosphogluconate.
Phosphogluconate dehydrogenase
Phosphogluconate dehydrogenase is an enzyme in the pentose phosphate pathway, forming ribulose 5-phosphate from 6-phosphogluconate.
Phosphogluconate dehydrogenase is an enzyme in the pentose phosphate pathway, forming ribulose 5-phosphate from 6-phosphogluconate.
Phosphopentose isomerase
Phosphopentose isomerase is an enzyme which converts ribulose 5-phosphate (a ketose) to ribose 5-phosphate (an aldose).
Phosphopentose isomerase is an enzyme which converts ribulose 5-phosphate (a ketose) to ribose 5-phosphate (an aldose).
Phosphopentose epimerase
Phosphopentose epimerase is an enzyme which intraconverts ribulose 5-phosphate and xylulose 5-phosphate, playing a role in the Calvin cycle and the pentose phosphate pathway.
Phosphopentose epimerase is an enzyme which intraconverts ribulose 5-phosphate and xylulose 5-phosphate, playing a role in the Calvin cycle and the pentose phosphate pathway.
