Question
Show me the 2nd stage of photosynthesis
Answers
GPT 3.5
The 2nd stage of photosynthesis is called the light-independent reactions, or the Calvin cycle. This stage takes place in the chloroplasts of the plant cells and converts the energy stored in ATP and NADPH, which were produced in the previous stage (light-dependent reactions), into glucose.
The Calvin cycle consists of three main steps:
1. Carbon Fixation: In this step, CO2 molecules from the atmosphere are combined with a 5-carbon organic compound called ribulose-1,5-bisphosphate (RuBP) using an enzyme called Rubisco. This results in the formation of an unstable 6-carbon compound, which quickly splits into two molecules of a 3-carbon compound called 3-phosphoglycerate (3-PGA).
2. Reduction: In the second step, ATP and NADPH produced during the light-dependent reactions are used to convert the 3-PGA molecules into another 3-carbon molecule called glyceraldehyde-3-phosphate (G3P). This step involves the transfer of energy from ATP and the transfer of electrons from NADPH to the 3-PGA molecules, producing G3P.
3. Regeneration: Some of the G3P molecules produced in the previous step are used to regenerate the initial 5-carbon compound (RuBP), which is crucial for the continuation of the Calvin cycle. This step requires the input of ATP.
The cycle continues, and for every six turns of the Calvin cycle, one molecule of glucose is produced. Glucose is then used by the plant for energy, growth, and various metabolic processes.
The Calvin cycle consists of three main steps:
1. Carbon Fixation: In this step, CO2 molecules from the atmosphere are combined with a 5-carbon organic compound called ribulose-1,5-bisphosphate (RuBP) using an enzyme called Rubisco. This results in the formation of an unstable 6-carbon compound, which quickly splits into two molecules of a 3-carbon compound called 3-phosphoglycerate (3-PGA).
2. Reduction: In the second step, ATP and NADPH produced during the light-dependent reactions are used to convert the 3-PGA molecules into another 3-carbon molecule called glyceraldehyde-3-phosphate (G3P). This step involves the transfer of energy from ATP and the transfer of electrons from NADPH to the 3-PGA molecules, producing G3P.
3. Regeneration: Some of the G3P molecules produced in the previous step are used to regenerate the initial 5-carbon compound (RuBP), which is crucial for the continuation of the Calvin cycle. This step requires the input of ATP.
The cycle continues, and for every six turns of the Calvin cycle, one molecule of glucose is produced. Glucose is then used by the plant for energy, growth, and various metabolic processes.