Cell Structure
Cell Structure
- Cells: Basic units of life, structured into two main types: prokaryotic cells (simple, single-celled organisms) and eukaryotic cells (complex, multicellular organisms).
- Prokaryotic Cells:
- Lacks a nucleus and other membrane-bound organelles.
- Contains a circular strand of DNA floating freely within the cell.
- Examples include bacteria and archaea.
- Eukaryotic Cells
- Possess a nucleus and other membrane-bound organelles.
- DNA is contained within the nucleus.
- Examples include animal, plant, and fungal cells.
Key Parts of a Cell
- Cell Membrane:
- Protective barrier that controls the movement of substances in and out of the cell.
- Made up of a phospholipid bilayer with embedded proteins.
- Nucleus:
- Control centre of the cell, contains cell's DNA.
- Surrounded by a nuclear membrane.
- Mitochondria:
- Powerhouse of the cell, provides energy through the process of respiration.
- Contains its own DNA.
- Ribosomes:
- Sites of protein synthesis.
- Found in all types of cells.
- Endoplasmic Reticulum:
- Network of membranous sacs involved in production, processing, and transport of proteins and lipids.
- Golgi Apparatus:
- Packaging centre of the cell, modifies and packages proteins for transport.
- Lysosomes:
- Digestive compartments filled with enzymes to break down waste material and cellular debris.
- Vacuoles and Vesicles:
- Storage compartments.
- Cytoskeleton:
- Provides structure and shape to the cell, involved in cell movement.
Differences between Animal and Plant Cells
- Cell Wall:
- Found in plant cells, provides rigidity and structural support.
- Absent in animal cells.
- Chloroplasts:
- Found in plant cells, site of photosynthesis.
- Absent in animal cells.
- Centrioles:
- Found in animal cells, involved in cell division.
- Rarely present in plant cells.
- Large central vacuole:
- Found in plant cells, stores water and nutrients.
- Small, numerous vacuoles present in animal cells.
For a comprehensive understand of cell structure and cell processes, diagrams and visual aids are helpful in conjunction with these points. Remember that mastering the basics provides a firm foundation for complex topics.