What You Will Learn

• Special structures in plant cells and their role

• Structure and function of chloroplasts

What Do Plants Have to Do That Animals Don't?

• Distinct structures in plant cells give them their unique shape.

• Plant cells have a rigid exterior to allow for upright growth.

• Photosynthesis: Plants make their own food.

Special Structures in Plant Cells

• Plant cells have unique structures not found in animal cells:

  • Cell Wall

  • Large Central Vacuole

  • Plastids (like Chloroplasts)

The Cell Wall

• Function: Provides structural support and protection.

• Structure: Made of cellulose and proteins.

• Prevents bursting: Controls water flow into the cell.

The Central Vacuole

• Takes up 30-90% of the plant cell’s volume.

• Function: Maintains turgor pressure, stores pigments, and helps in defense.

• Stores: Water, enzymes, ions, salts, and other substances.

Plastids

• Different types of plastids:

  • Chloroplasts: Photosynthesis (makes food).

  • Chromoplasts: Store pigments (color of flowers/fruits).

  • Leucoplasts: Storage of starch and synthesis of molecules.

Chloroplasts

• Function: Capture sunlight and convert it into food through photosynthesis.

• Structure:

  • Enclosed by an inner and outer membrane.

  • Contains stacks of thylakoids arranged into grana.

  • Stroma: The fluid inside, contains DNA and ribosomes.

Summary

• Plant cells have unique structures like the cell wall, central vacuole, and plastids.

• Cell wall provides support and protection.

• Central vacuole helps with storage and maintaining cell pressure.

• Chloroplasts perform photosynthesis, converting sunlight into food for the plant.