Lecture Notes: Photosynthesis and Plant Adaptations

Introduction

• Discusses special abilities of organisms.
  • Example: Flying like a peregrine falcon.
  • Example: Walking up walls like a Texas banded gecko.
• Desire for plant abilities, specifically photosynthesis.
  • Plants, some protists, and bacteria can perform photosynthesis.
  • Photosynthesis produces oxygen, essential for animals and humans.
  • Plants are crucial in food webs and ecosystems.
  • Many medications and foods are derived from plants.

Photosynthesis Overview

• Process where plants make their own food (glucose).
• Balanced equation for photosynthesis often seen in biology textbooks.
• Photosynthesis inputs/outputs related to cellular respiration.
  • Photosynthesis produces glucose which is used in cellular respiration.
  • Cellular respiration produces energy (ATP).

Light Capturing in Plants

• Plants capture light using pigments.
  • Visible light has different wavelengths, appearing as different colors.
  • Chlorophyll: A pigment that absorbs red and blue light but reflects green light.
  • Chlorophyll is located in chloroplasts.

Photosynthesis Reactions

• Two major reactions in chloroplasts:
  • Light Dependent Reactions
    • Occur in thylakoids (compartments within chloroplasts).
    • Light is captured, water is split (produces electrons, protons, oxygen).
    • Produces ATP and NADPH needed for the next reaction.
  • Light Independent Reactions (Calvin Cycle)
    • Occur in the stroma (fluid outside thylakoids).
    • Carbon dioxide enters through stomata (pores in leaves).
    • Carbon dioxide is fixed using ATP and NADPH from light-dependent reactions.
    • Results in production of glucose.

Plant Adaptations

• Plants have adaptations to perform photosynthesis in various environments.
  • Example: Cacti with CAM photosynthesis.
  • Cacti open stomata at night to minimize water loss.
  • Store CO2 chemically to use during day.

Conclusion

• Encouragement to explore more detailed aspects of photosynthesis.
• Mention of plant adaptations like leaf shapes and pigments.

• Note: Further reading links are provided in the video description for additional detail.
• Amoeba Sisters' Encouragement: Stay curious about the natural world.