11:115:301 Lecture Notes - Lecture 17: Pentose Phosphate Pathway, Phosphoglycerate Kinase, Light-Independent Reactions

• School: Rutgers University
• Department: Biochemistry
• Course: 11:115:301
• Professor: Murphy

Document Summary

The calvin cycle + the pentose phosphate pathway. Every winter leaves fall off trees decompose release co2. The calvin cycle fixes co2 to produce hexoses. Fixation: co2 is fixed by combining with ribulose 1,5-bisphosphate 2 molecules of 3-pg (3-phosphoglycerate) Reduction (part of gluconeogenesis): 3-phosphoglycerate is converted to fructose 6-phosphate. Regeneration (part of pentose phosphate pathway): ribulose 1,5-bisphosphate is regenerated from 3c sugars so that more co2 can be fixed. Takes place in the stroma of chloroplasts. To be self-perpetuating cycle must repeat 6x to make one f6p from co2. Must regenerate the (six) 5c starting sugars from 3c sugars. To regenerate 5c sugar cell will use generic enzymes and interconvert various. Calvin cycle = dark reaction of photosynthesis . Rubisco = the most abundant protein on earth. Catalyzes the rate-limiting step in hexose synthesis. Comprises 30% of total leaf protein in some plants. 3-phosphoglycerate + atp --phosphoglycerate kinase--> 1,3-bisphosphoglycerate + adp. 1,3-bisphosphoglycerate + nadph + h+ --glyceraldehyde 3-phosphate dehydrogenase--