Lecture on Cell Structure, Function, and Organization

Introduction

• Focus: Life and Physical Science
• Topic: Cell structure, function, and organization

Biological Systems Hierarchy

• Levels of organization
  • Cell: Fundamental unit of life
  • Organelle: Smaller structures within cells
  • Biomolecules: Crucial components within cells
  • Atoms and Subatomic Particles: Smaller than cells, basis for all structures

Cellular Level

• Universal to all living things: bacteria, fungi, plants, animals
• Tissues: Groups of cells performing unified functions (e.g., cardiac muscle tissue)
• Organs: Composed of tissues (e.g., heart, lungs, kidneys)
• Organ Systems: Collaboration of organs (e.g., digestive system)
• Organism: Result of interconnected organ systems
• Higher biological hierarchies: population, community, ecosystem, biomes, biosphere

Practice Questions

1. Correct hierarchy sequence: Cells → Tissues → Organs → Organ Systems → Organisms
2. Correct about organ systems: Organisms consist of multiple organ systems working together

Modern Cell Theory

• Cells as the fundamental unit of life
• All living entities are composed of cells (unicellular or multicellular)
• Cells arise from existing cells (capable of replication)

Types of Cells: Prokaryotes vs Eukaryotes

• Prokaryotes: Bacteria and Archaea; no nucleus; no membrane-bound organelles
• Eukaryotes: Fungi, protists, animals, plants; have nucleus and membrane-bound organelles

Memory Trick

• "Pro" means "No" (no nucleus or membrane-bound organelles in prokaryotes)
• "Eu" means "Do" (have nucleus and membrane-bound organelles)

Organelles and Their Functions

• Cell Membrane (Plasma Membrane): Selective permeability; maintains homeostasis
• Cytoplasm: Jelly-like substance; supports internal structures
• Cytoskeleton: Provides structural support, aids in cellular movement
• Ribosomes: Not membrane-bound; protein synthesis; present in both prokaryotes and eukaryotes

Eukaryotic Organelles

• Nucleus: Control center; contains DNA
• Nucleolus: Assembles ribosomes
• Endoplasmic Reticulum (ER): Rough (with ribosomes) for protein synthesis and transport; Smooth for detoxification and lipid synthesis
• Golgi Apparatus: Packaging and distribution; modifies and organizes molecules
• Mitochondria: ATP production through cellular respiration (Powerhouse of the cell)
• Chloroplasts: Photosynthesis in plant cells
• Lysosomes: Break down biomolecules; maintain cellular cleanliness
• Vacuoles: Store nutrients and waste; maintain pressure; present in plant cells

Practice Questions

1. Ribosomes: Assemble proteins using instructions from mRNA
2. Mitochondria: Known as the Powerhouse of the cell, producing ATP

Conclusion

• Understanding cell structure, function, and organization
• Additional resources available at nursechunkstore.com

• Note: This summary covers the fundamental aspects of cell structure and their organizational hierarchy in life sciences. Practice questions help reinforce understanding of concepts.