Final answer:
The incorporation of CO₂ into glucose during photosynthesis is called carbon fixation, occurring in the Calvin cycle. This endothermic reaction requires energy from sunlight captured during the light-dependent reactions of photosynthesis.
Step-by-step explanation:
The process of incorporating CO₂ into organic molecules like glucose during photosynthesis is known as carbon fixation. This occurs in the Calvin cycle, which is the second stage of photosynthesis and is also referred to as the light-independent reactions. During carbon fixation, CO₂ is attached to a five-carbon sugar named ribulose bisphosphate (RuBP) by the enzyme RuBisCO, resulting in a six-carbon compound that is immediately converted into two molecules of a three-carbon compound, 3-phosphoglycerate (3-PGA). These molecules are then converted through a series of reactions into the higher energy molecule glyceraldehyde-3-phosphate (GA3P), and eventually glucose.
The photosynthesis reaction overall can be represented by the equation:
6CO₂(g) + 6H₂O(l) → C₆H₁₂O₆(s) + 6O₂(g)
This reaction is endothermic, meaning it requires an input of energy to proceed. This energy comes from sunlight, which is captured by chlorophyll in the chloroplasts of plant cells during the light-dependent reactions.