Photosynthesis and Carbohydrates

Introduction

• 60% of food intake consists of carbohydrates.
• Carbohydrates contain carbon, hydrogen, and oxygen.

Origin of Atoms for Carbohydrates

• Carbon dioxide from the air is used by plants.
• Water provides hydrogen and oxygen atoms through plant roots.

Chloroplast and Chlorophyll

• Chloroplasts are plant organelles responsible for photosynthesis.
  • Each leaf has ~44,000 cells.
  • Each cell can have 20-100 chloroplasts (totaling up to 4,400,000 per leaf).
• Chlorophyll is the green pigment aiding in light absorption.

Photosynthesis Process

• Plants split water molecules for electrons.
• Sunlight provides necessary energy for water molecule breakdown.
• Products of photosynthesis include glucose (C6H12O6).

Role of Glucose

• Glucose is a simple carbohydrate formed.
• It can be converted into:
  • Cellulose: Provides structural support for plants; called fiber in human diet.
  • Starch: Energy storage for plants; consumed by humans as potatoes, corn, rice.

Human and Plant Connection

• Humans utilize plant-produced carbohydrates.
• Glucose from plants is broken down into ATP in mitochondria.

ATP - Energy Currency

• ATP (Adenosine Triphosphate) is the energy currency for cells.
  • Glucose is analogous to ice cream cones; needs conversion to ATP (dollars).
• Both humans and plants have mitochondria to convert glucose into ATP.

Symbiotic Relationship

• Humans and plants have a reciprocal relationship:
  • Humans exhale CO2 used by plants.
  • Plants release O2 necessary for human cellular respiration.

Conclusion

• Photosynthesis is crucial for energy transformation and sustaining life.
• The process connects and sustains both plant and human life.