Photosynthesis

• Definition: Process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose.

• Equation: 6CO2 + 6H2O + light energy -> C6H12O6 + 6O2.

• Stages:

  1. Light-dependent reactions: Occur in thylakoid membranes of chloroplasts, require light energy to split water molecules and produce ATP and NADPH.

  2. Calvin cycle (Light-independent reactions): Occur in stroma of chloroplasts, use ATP and NADPH to convert CO2 into glucose.

• Importance:

  • Produces oxygen as a byproduct, essential for respiration.

  • Primary source of energy for most living organisms.

  • Regulates atmospheric CO2 levels.

• Factors affecting photosynthesis:

  • Light intensity.

  • Carbon dioxide concentration.

  • Temperature.

• Adaptations:

  • Chlorophyll pigment absorbs light.

  • Leaf structure maximizes light absorption.

• Significance:

  • Basis of the food chain.

  • Sustains life on Earth.

• Environmental impact:

  • Helps reduce greenhouse gases.

  • Influences climate change.