Photosynthesis - Basics:

• Photosynthesis is the process by which green plants, algae, and some bacteria convert sunlight, water, and carbon dioxide into glucose (a form of sugar) and oxygen.
• It takes place in the chloroplasts, which are specialized organelles found in the cells of plants and algae.
• Photosynthesis is vital for life on Earth as it is responsible for producing oxygen and is the primary source of energy for most living organisms.

Equation for Photosynthesis:

• The overall equation for photosynthesis is: 6 CO2 + 6 H2O + sunlight → C6H12O6 + 6 O2 (carbon dioxide + water + sunlight → glucose + oxygen)
• This equation represents the process of photosynthesis, where carbon dioxide, water, and sunlight are converted into glucose and oxygen.

Factors Affecting Photosynthesis:

1. Light Intensity:
   • Light is the primary source of energy for photosynthesis.
   • Higher light intensity generally leads to increased photosynthetic activity, as more energy is available for the process.
   • However, excessively high light intensity can damage the photosynthetic machinery.
2. Carbon Dioxide (CO2) Concentration:
   • Carbon dioxide is one of the reactants required for photosynthesis.
   • Sufficient carbon dioxide levels are necessary for optimal photosynthetic activity.
   • Higher concentrations of carbon dioxide generally increase the rate of photosynthesis, up to a certain point.
3. Temperature:
   • Photosynthesis is temperature-sensitive, with an optimal temperature range for maximum efficiency.
   • Low temperatures can slow down the process, as enzymes involved in photosynthesis become less active.
   • Very high temperatures can denature enzymes and impair photosynthesis.
4. Water Availability:
   • Water is essential for photosynthesis, as it is one of the reactants and helps transport nutrients within the plant.
   • Sufficient water availability is necessary for optimal photosynthetic activity.
   • Insufficient water supply can limit photosynthesis and lead to stunted growth.
5. Chlorophyll Content:
   • Chlorophyll, the green pigment found in chloroplasts, plays a crucial role in capturing light energy.
   • Plants with higher chlorophyll content generally have greater photosynthetic capacity.
   • Changes in chlorophyll levels can affect the rate of photosynthesis.

C1.3 Photosynthesis

Light Energy to Chemical Energy:

• Light energy is harnessed by pigments, primarily chlorophyll, within the thylakoid membranes of chloroplasts.
• This energy powers the conversion of carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and oxygen (O2) through photosynthesis.
• Photosynthesis consists of two stages: the light-dependent reactions in the thylakoid membrane and the light-independent reactions (Calvin cycle) in the chloroplast stroma.

Flowchart of Energy Conversions: