Nutrition and Photosynthesis

Nutrition

Types of Nutrition

• Autotrophic Nutrition: Organisms that produce their own food using light, water, and carbon dioxide. Examples: plants, algae, and some bacteria.
• Heterotrophic Nutrition: Organisms that obtain their food by consuming other organisms or organic matter. Examples: animals, fungi, and some bacteria.

Modes of Nutrition

• Holozoic Nutrition: Organisms that ingest solid food particles. Examples: animals, protozoa.
• Saprotrophic Nutrition: Organisms that obtain their food by breaking down dead organic matter. Examples: fungi, bacteria.
• Parasitic Nutrition: Organisms that obtain their food by living on or inside another organism. Examples: tapeworms, mistletoe.

Nutritional Requirements

• Macronutrients: Carbohydrates, proteins, and fats.
• Micronutrients: Vitamins and minerals.

Photosynthesis

Definition

• Photosynthesis: The process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose.

Equation

• 6 CO2 + 6 H2O + light energy → C6H12O6 (glucose) + 6 O2

Importance of Photosynthesis

• Produces oxygen for aerobic organisms.
• Provides energy for food chains.
• Supports aquatic life.

Factors Affecting Photosynthesis

• Light: Intensity, quality, and duration.
• Temperature: Optimal temperature range for enzyme activity.
• Water: Availability and quality.
• Chlorophyll: Presence and amount of the green pigment.

Stages of Photosynthesis

• Light-dependent reactions: Light absorption, electron transport, and ATP synthesis.
• Light-independent reactions (Calvin cycle): Carbon fixation, reduction, and regeneration.