1. Nucleus:
* Function: Contains the cell's genetic material (DNA) and controls cellular activity.
* Key Features: Enclosed by a double membrane called the nuclear envelope, contains nucleolus (site of ribosome synthesis).
2. Ribosomes:
* Function: Synthesize proteins.
* Key Features: Found free in cytoplasm or attached to endoplasmic reticulum, composed of ribosomal RNA and proteins.
3. Endoplasmic Reticulum (ER):
* Function: Modifies and transports proteins, synthesizes lipids and steroids.
* Key Features: Network of interconnected membranes, divided into rough ER (with ribosomes) and smooth ER (without ribosomes).
4. Golgi Apparatus:
* Function: Packages, modifies, and sorts proteins and lipids for secretion or use in other organelles.
* Key Features: Stack of flattened membrane-bound sacs called cisternae.
5. Mitochondria:
* Function: Produce ATP (energy) through cellular respiration.
* Key Features: Double membrane, contain their own DNA, often referred to as the "powerhouse of the cell".
6. Lysosomes:
* Function: Digest cellular waste, debris, and pathogens.
* Key Features: Membrane-bound sacs containing hydrolytic enzymes.
7. Peroxisomes:
* Function: Detoxify harmful substances, break down fatty acids.
* Key Features: Small, membrane-bound organelles containing oxidative enzymes.
8. Centrosomes:
* Function: Organize microtubules during cell division.
* Key Features: Contain two centrioles, cylindrical structures composed of microtubule triplets.
9. Cytoskeleton:
* Function: Provides structural support, facilitates movement, and aids in intracellular transport.
* Key Features: Network of protein filaments: microtubules, microfilaments, and intermediate filaments.
10. Plasma Membrane:
* Function: Regulates what enters and exits the cell, maintains cell shape.
* Key Features: Phospholipid bilayer with embedded proteins.
11. Vacuoles:
* Function: Storage of water, nutrients, and waste products.
* Key Features: Large, fluid-filled sacs in plant cells, smaller and more numerous in animal cells.
Note: Animal cells lack chloroplasts, cell walls, and plasmodesmata found in plant cells.
