3-phosphoglycerate

Definition

3-phosphoglycerate (3-PGA) is a 3-carbon molecule formed during the Calvin cycle of photosynthesis. It is an intermediate that plays a crucial role in the synthesis of glucose.

5 Must Know Facts For Your Next Test

1. 3-phosphoglycerate is produced from ribulose-1,5-bisphosphate (RuBP) through the action of the enzyme RuBisCO.
2. It is one of the first stable products formed in the Calvin cycle after carbon fixation.
3. 3-PGA can be converted into glyceraldehyde-3-phosphate (G3P), which is used to generate glucose and other carbohydrates.
4. The conversion of 3-PGA to G3P requires ATP and NADPH, which are products of the light-dependent reactions of photosynthesis.
5. In C4 and CAM plants, 3-phosphoglycerate still plays a role but via different initial steps involving alternative pathways.

Review Questions

Related terms

Calvin Cycle:

A series of biochemical reactions that occur in the stroma of chloroplasts during photosynthesis.

RuBisCO:

An enzyme that catalyzes the carboxylation of ribulose-1,5-bisphosphate, initiating carbon fixation.

Glyceraldehyde-3-phosphate (G3P): A three-carbon molecule that serves as an intermediate in both glycolysis and photosynthesis.