Science Classroom Experience

Memorable Science Day

• 9th Grade Experience: Witnessing an amoeba under a microscope.
  • Realization of cells and their abundance in organisms.

Modern Cell Theory

• Key Points:
  1. Cell is the smallest living unit in organisms.
  2. All living things are made of cells (unicellular or multicellular).
  3. All cells come from pre-existing cells.

Types of Cells

• Prokaryotes:
  • No nucleus or membrane-bound organelles.
  • Examples: Bacteria and Archaea.
• Eukaryotes:
  • Have a nucleus and membrane-bound organelles.
  • Includes all other living organisms.

Cellular Components and Functions

• Cell Membrane:
  • Selectively permeable; maintains homeostasis.
• Cytoplasm:
  • Jelly-like substance supporting cell structures.
• Cytoskeleton:
  • Provides support and aids in cell movement.
• Ribosomes:
  • Produce proteins; found in both prokaryotes and eukaryotes.

Eukaryotic Organelles

• Nucleus:
  • Contains DNA; controls cell activities.
  • Includes nucleolus (ribosome production).
• Endoplasmic Reticulum (ER):
  • Rough ER: Protein production and transport.
  • Smooth ER: Detoxification and lipid synthesis.
• Golgi Apparatus:
  • Modifies, sorts, and packages proteins and lipids.
• Mitochondria:
  • Powerhouse of the cell; produces ATP energy.
• Chloroplasts (Plant Cells):
  • Photosynthesis; contains chlorophyll.
• Vacuoles:
  • Storage; large central vacuole in plant cells.

Differences Between Plant and Animal Cells

• Plant Cells:
  • Have chloroplasts, large central vacuole, and cell wall.
• Animal Cells:
  • Lack the above structures, have several smaller vacuoles.

Protein Synthesis Journey

• Process:
  1. Instructions from DNA in nucleus.
  2. Made by ribosomes.
  3. Transported via rough ER.
  4. Sorted in Golgi apparatus.
  5. Secreted through cell membrane if tagged.

Conclusion

• Encouragement to explore more about eukaryotic cell organelles.
• Reminder to stay curious.