Page 1: The Light-Dependent Reactions of Photosynthesis
The first page of the transcript focuses on the light-dependent reactions of photosynthesis, also known as the faza jasna fotosyntezy. This phase occurs in the thylakoid membranes of chloroplasts and involves the conversion of light energy into chemical energy.
Definition: Photosynthesis is the process of synthesizing organic compounds from inorganic substances using sunlight energy.
The overall equation for photosynthesis is presented:
6 CO₂ + 6 H₂O + Energy → C₆H₁₂O₆ + 6 O₂ + 6 H₂O
Key components of the light-dependent reactions include:
- Pigments: Chlorophyll a and b are the primary pigments, with carotenoids serving as accessory pigments.
Vocabulary: Chlorophyll is the green pigment responsible for absorbing light energy in photosynthesis.
- Photosystems: Two types are mentioned - Photosystem I PSI and Photosystem II PSII.
Highlight: Photosystem I contains chlorophyll that absorbs light at 700 nm P−700, while Photosystem II absorbs at 680 nm P−680.
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Light absorption: Chlorophyll primarily absorbs violet and red light, while reflecting green light.
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Energy conversion: Light energy is converted into chemical energy in the form of ATP and NADPH.
The page also mentions photorespiration, a process that occurs under conditions of high oxygen concentration, high light intensity, high temperature, and water deficiency.
Example: Photorespiration can reduce photosynthetic efficiency in some plants, especially in hot, dry environments.
