Plant Cell - Basic Unit of Life in Plants

Overview

• Plant cells are the fundamental units of life in all plants.
• Key structures of the plant cell and their functions.

Major Structures and Functions

1. Cell Wall

• Composition: Made of cellulose.
• Function: Provides strength and structural support.
• Permeability: Allows free movement of fluid through it.

2. Cell Membrane

• Alternate Name: Phospholipid bilayer.
• Function: Separates the cell from the external environment.
• Selective Permeability: Controls inflow and outflow of water, molecules, and compounds.

3. Cytoplasm

• Definition: Everything within the cell membrane, including organelles and proteins.
• Cytosol: The fluid where organelles move.

4. Central Vacuole

• Function: Storage and maintenance of plant shape and stability.
• Turgor Pressure: Provides rigidity; underwater plants lacking full vacuoles appear limp.

5. Golgi Apparatus (Golgi Body)

• Function: Packaging and shipping center.
• Process: Modifies molecules and proteins, sends them in vesicles.

6. Ribosomes

• Composition: Made of proteins and RNA.
• Function: Translate RNA into proteins for cellular use.
• Location: Free-floating or bound to the endoplasmic reticulum.

7. Endoplasmic Reticulum (ER)

• Types:
  • Rough ER: Produces and stores proteins, has ribosomes giving it a rough texture.
  • Smooth ER: No ribosomes, involved in lipid production, and detoxification.

8. Nucleus

• Function: Central role in cell function (not always centrally located).
• DNA Storage: Houses and protects DNA.
• Transcription: DNA transcribed to RNA; information affects cell function and gene expression.

9. Mitochondria

• Nickname: Powerhouse of the cell.
• Function: Main ATP producer (energy currency).

10. Chloroplast

• Function: Converts sunlight into basic carbohydrates.
• Role: Source of usable energy for most living organisms.

11. Cytoskeleton

• Composition: Microtubules and microfilaments.
• Function: Provides shape and structural support.

12. Centrosomes

• Location: Near the nucleus.
• Function: Produce microtubules, critical in mitosis, and cell division.

Conclusion

• Plant cells contain diverse structures with specialized functions essential for plant life and energy production.