Calvin cycle

• The Calvin Cycle is the first stage of photosynthesis.
• NADPH is produced by reducing NAD+ with electrons from PSII.
• Photosystem II (PSII) splits water into oxygen, electrons, protons, and hydrogen atoms.
• Light-dependent reactions occur in thylakoid membranes.
• Photorespiration allows plants to adapt to periods of high light intensity when the rate of photosynthesis exceeds the rate at which ATP can be utilized.
• Photosystem II (PSII) splits water into oxygen, protons, electrons, and hydrogen atoms.
• Photorespiration reduces the amount of oxygen available for mitochondrial respiration and ATP synthesis.
• Photorespiration leads to the production of ammonia which can be reassimilated as amino acids.
• ATP synthase uses ADP and Pi to produce ATP.
• Light-independent reactions occur in stroma.
• RuBP regeneration requires ATP, which is provided by light reactions.
• Light energy drives the conversion of ADP + Pi into ATP.
• ATP is used to drive the reduction of CO2 into glycerate-3-phosphate (G3P).
• Electron transport chain transfers energy to ATP synthase, producing ATP.
• Light-dependent reactions occur in chloroplast thylakoid membranes.
• ATP synthase uses ATP to produce ADP and phosphate.
• Rubisco catalyses two different reactions - carboxylation and oxygenation.
• The Calvin Cycle is also known as the Light Independent Reactions or Dark Reaction.
• RuBP regeneration requires energy input from ATP and reductant input from NADPH.
• ATP synthase uses the energy stored in H+ gradients across the thylakoid membrane to synthesize ATP.
• RuBP regeneration requires energy from ATP and reducing power from NADPH.
• Carbon dioxide fixation involves RuBisCO catalysis and produces two molecules of three-carbon sugar.
• The Calvin cycle is also known as the dark reaction or carbon fixation.
• Carbon dioxide enters through stomata and diffuses across the cell membrane.
• Carbon dioxide enters chloroplast through stomata or diffusion from air spaces.
• The process involves two cycles - the first cycle produces G3P from RuBP, while the second cycle converts G3P back to RuBP.
• Photosystem II uses water as an electron donor to produce oxygen gas.
• In the first cycle, three molecules of carbon dioxide are fixed per turn of the cycle.
• In stage one, Rubisco catalyzes the carboxylation reaction between CO2 and Ribulose bisphosphate (RuBP), forming two molecules of unstable 3-phosphoglyceric acid (3PG).
• Complex I accepts electrons from NADPH and passes them through a series of redox reactions.
• The electrons from photosystem II are transferred through cytochrome b6f complex and plastoquinone to NADPH.
• Carbon dioxide enters the stroma through diffusion or active transport.
• The second cycle regenerates RuBP using one molecule of G3P.
• The Calvin cycle occurs in the stroma of chloroplasts.
• In stage one (carbon fixation), CO2 combines with ribulose bisphosphate (RuBP) catalyzed by Rubisco enzyme to form unstable molecule that breaks down into two phosphoglyceric acid (PGA).
• Cape agriculture unit 1 syllabus