6 Questions
Where do the light-dependent reactions of photosynthesis primarily occur?
Thylakoid membrane
Which molecule is the primary product of carbon fixation in the Calvin Cycle?
3-PGA
Which enzyme is responsible for carbon fixation during the Calvin Cycle?
RuBisCO
What are the final products of the light-dependent reactions?
ATP and NADPH
What role does the proton gradient play in the light-dependent reactions?
It drives the synthesis of ATP.
How does photosynthesis contribute to the regulation of Earth's climate?
By removing CO2 from the atmosphere
Study Notes
Overview of Photosynthesis
- Definition: Process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of organic compounds, such as glucose.
- Occurs in specialized organelles called chloroplasts, found in plant cells.
Light-Dependent Reactions
- Light absorption: Light energy is absorbed by pigments such as chlorophyll and other accessory pigments in the thylakoid membrane.
- Electron transport: Energy from light is used to generate a proton gradient, driving the synthesis of ATP and NADPH.
- ATP and NADPH production: ATP and NADPH are produced and used to fuel the light-independent reactions.
Light-Independent Reactions (Calvin Cycle)
- Carbon fixation: CO2 is fixed into a 3-carbon molecule called 3-phosphoglycerate (3-PGA) via the enzyme RuBisCO.
- Reduction reactions: 3-PGA is reduced to form glyceraldehyde 3-phosphate (G3P) using ATP and NADPH produced in the light-dependent reactions.
- Regeneration: The G3P molecules are used to regenerate RuBP, the 5-carbon molecule that binds to CO2.
Net Equation of Photosynthesis
- 6 CO2 + 6 H2O + light energy → C6H12O6 (glucose) + 6 O2
Importance of Photosynthesis
- Produces oxygen: Oxygen is released as a byproduct, supporting aerobic life.
- Supports food chains: Glucose produced during photosynthesis is used as energy and building blocks for other organisms.
- Regulates Earth's climate: Photosynthesis removes CO2 from the atmosphere, helping to regulate Earth's climate.
Definition and Overview
- Process that converts light energy into chemical energy, producing organic compounds like glucose.
- Occurs in chloroplasts, specialized organelles in plant cells.
Light-Dependent Reactions
- Light energy is absorbed by pigments like chlorophyll and other accessory pigments in the thylakoid membrane.
- Energy from light generates a proton gradient, driving synthesis of ATP and NADPH.
- ATP and NADPH are produced, fueling light-independent reactions.
Light-Independent Reactions (Calvin Cycle)
- CO2 is fixed into 3-phosphoglycerate (3-PGA) via RuBisCO enzyme.
- 3-PGA is reduced to glyceraldehyde 3-phosphate (G3P) using ATP and NADPH.
- G3P molecules regenerate RuBP, the 5-carbon molecule that binds to CO2.
Net Equation of Photosynthesis
- 6 CO2 + 6 H2O + light energy → C6H12O6 (glucose) + 6 O2
Importance of Photosynthesis
- Produces oxygen, supporting aerobic life.
- Supports food chains, with glucose used as energy and building blocks.
- Regulates Earth's climate by removing CO2 from the atmosphere.
Learn about the process of photosynthesis, where plants and some organisms convert light energy into chemical energy, and its light-dependent reactions.
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