Animal Cells Overview

Animal Cells

  • Definition: Eukaryotic cells lacking certain structures found in plant cells.

  • Key Features:

    • Membrane-bound nucleus

    • Membrane-bound organelles

    • No cell wall, leading to irregular shape and ability to change shape

    • Mitochondria produce ATP (usable energy)

    • Smooth endoplasmic reticulum (ER) synthesizes lipids and phospholipids

    • No chloroplasts or large vacuoles (if any)

    • Present: Centrioles (absent in most plant cells)

    • Microvilli may be present, increasing surface area

Organelles in Animal Cells

  • Lysosomes: Sac-like and contain enzymes for breakdown processes.

  • Rough Endoplasmic Reticulum (Rough ER): Ribosomes attached; site of protein synthesis.

  • Plasma Membrane: Semi-fluid phospholipid bilayer; controls substance movement.

  • Small Vacuoles: Not always present.

  • Ribosomes: Protein synthesis; can be free or attached to rough ER.

  • Nuclear Pore: Allows passage between nucleus and cytoplasm.

  • Nucleus: Contains most of the cell's DNA; contains nucleolus.

  • Golgi Apparatus: Processes and transports proteins; vesicles bud off from it to transport products.

  • Cytoplasm: Gel-like substance filling the cell.

  • Centrioles: Form spindle fibers for nuclear division; organized in pairs at 90°.