Cell & Molecular Biology Lecture Notes

Introduction

• Class Details: Cell & Molecular Biology (BIOL140A-03-1, Sp24)
• Lecturer: Claudia Stone
• Meeting Date: 02/06/2024
• Duration: 59 minutes
• Participants: 51 students
• Upcoming Midterm: February 13, closed book, 25 multiple-choice questions + extra credit

Cell Basics

• Cell Types:
  • Prokaryotic Cells: Lack nucleus, simple structure, e.g., bacteria, archaea
  • Eukaryotic Cells: Have nucleus, complex structure, e.g., animals, plants
• Main Learning Outcomes:
  • Distinguish between prokaryotic and eukaryotic cells
  • Understand main cellular components and their functions

Microscopy

• Light Microscopy:
  • Useful for viewing plant and animal cells
  • Limited resolution (200 nanometers)
• Fluorescence Light Microscopy:
  • Uses stains and lasers for cell imaging
• Super-Resolution Microscopy:
  • Breakthrough in resolution beyond 200 nm
  • Uses computational methods

Electron Microscopy

• Types:
  • Scanning Electron Microscopy (SEM): Provides 3D images of surfaces
  • Transmission Electron Microscopy (TEM): Provides 2D images by transmitting electrons through thin samples
• Cryo-Electron Microscopy:
  • Allows visualization of macromolecules like SARS-CoV-2 spike proteins
  • 2017 Nobel Prize for chemistry

Cell Structures

• Prokaryotic Cells:
  • Lack nucleus and membrane-bound organelles
  • DNA concentrated in nucleoid
  • Have cell walls, and some have flagella for movement
• Eukaryotic Cells:
  • Nucleus with DNA wrapped around histones (chromatin)
  • Endomembrane system including ER, Golgi apparatus
  • Cytoskeleton for structure and transport
  • Specialized structures like lysosomes for digestion

Plant vs Animal Cells

• Animal Cells:
  • Lack cell wall, central vacuole
  • Have small organelles like mitochondria
  • Sometimes have microvilli
• Plant Cells:
  • Have cell wall made of cellulose
  • Large central vacuole for storage and growth
  • Contain chloroplasts for photosynthesis

Special Focus

• Protein Processing:
  • Rough ER: Protein synthesis for secretion or membrane
  • Smooth ER: Lipid synthesis
  • Golgi apparatus: Modification and packaging of proteins
• Cytoskeleton:
  • Made of microtubules, actin filaments
  • Important for cell shape, transport, and division

Conclusion

• Review for Midterm:
  • Focus on distinguishing cell types, understanding cell structure
  • Practice exam available on Canvas
• Final Notes:
  • Emphasis on understanding concepts over memorizing details
  • Be familiar with microscopy techniques and cell structures

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Additional Resources

• Slides will be posted online
• Practice exams and further reading on Canvas