Cell Organelles

Cell Organelles

Important Terms

  • Nucleus
  • Cell/Plasma Membrane
  • Endoplasmic Reticulum
  • Vacuoles and Vesicles
  • Lysosomes
  • Mitochondria
  • Golgi Apparatus
  • Cytoskeleton
  • Centrioles
  • Cilia and Flagella
  • Chloroplasts (Plants Only)

Cell Parts

  • Cells - the basic unit of life.
  • Organelles - small structures inside a cell with specific functions.
  • Analogy: Similar to parts of a city, each organelle has a different job to ensure the cell works well and maintains a healthy life.

A) Cell Membrane / Plasma Membrane

  • Analogy: City limits / City boundaries.
  • Function: Regulates materials entering and exiting the cell.
  • Structure: Two layers of phospholipids and proteins.

B) Cytoplasm

  • Function: All cell contents between the cell membrane and the nucleus, including organelles and cytosol.
    • Cytosol = liquid portion / non-organelles.
  • Structure: Fluid and organelles, excluding the nucleus.
  • Analogy: All air, water, and life in the city, except City Hall.

C) Nucleus

  • Function: "Control Center." Regulates DNA & RNA actions.
  • Structure: Membrane-bound, contains DNA.
  • Analogy: City Hall.

D) Nuclear Envelope

  • Analogy: Walls & Doors of City Hall.
  • Function: Regulates what enters or exits the nucleus.
  • Structure: Double Layer of Lipids.

E) Nucleolus

  • (A region in the nucleus, not an organelle).
  • Analogy: The Mayor.
  • Function: Produces RNA, which is used (mostly) to make all proteins.
  • Structure: Zone inside the Nucleus, Dense area of DNA and nuclear activity.

F) DNA – Deoxyribonucleic acid

  • (Not an organelle, but contained in one.)
  • Analogy: The Laws or City Code.
  • Function: Information on how to make proteins.
    • Chromatin – unorganized DNA (normal state).
    • Chromosomes – organized DNA (present before cell division)
  • Structure: Made up of nucleotides, locked in the nucleus.

G) Endoplasmic Reticulum

  • Analogy: Roads & Sidewalks.
  • Function: Transportation route for proteins.
    • Rough ER: has ribosomes.
    • Smooth ER: no ribosomes (not protein-related, more involved in lipid production and detox).
  • Structure: Membrane (lipid bilayer) tubes and channels.

H) Ribosomes

  • Analogy: Restaurants, Factories, Builders.
  • Function: Makes proteins.
  • Structure: Small circular organelles.

I) Vacuoles & Vesicles

  • Analogy: Grocery stores, water tanks.
  • Function: Storage for water, nutrients, or waste.
  • Structure: Small membrane-bound organelle.

J) Lysosomes (Animals Only)

  • Analogy: Recycling center.
  • Function: Packets of enzymes that break down materials in a cell.
  • Structure: Small membrane-bound organelles.
  • Destroy/Digest invading bacteria/materials/food, etc.

K) Mitochondria

  • Analogy: Electric Power Plant.
  • Function: Produce energy for the cell – site of cellular respiration. “The Powerhouse”.
  • Structure: Double membrane-bound, kidney-shaped.

L) Golgi Apparatus

  • Analogy: Post Office / FedEx.
  • Function: Packages, labels, and ships proteins around and out of the cell.
  • Structure: Pancake-shaped layered organelle.

M) Cytoskeleton

  • Analogy: Wood, cement, steel beams.
  • Function: Provide support and structure for the cell.
    • Microfilaments.
    • Microtubules.
  • Structure: Tubules.

N) Centrioles (Animals Only)

  • Analogy: Your High School Team vs. Visiting High School Team.
  • Function: Microtubules that help divide the cell during cell division.
  • Structure: Tubules.

O) Cilia & Flagella

  • Analogy: Cars or bicycles.
  • Function: Provides movement for the cell or objects moving by the cell.
  • Structure:
    • Flagella – 1 long fiber.
    • Cilia – many short fibers.

P) Chloroplasts (Plants only)

  • Analogy: Solar Panels.
  • Function: Site of photosynthesis (converting sun and CO2CO_2 into sugar).
  • Structure: Membrane-bound organelles that contain chlorophyll.

Q) Cell Wall (Plant cells only)

  • Analogy: Ground, rock wall.
  • Function: Provides support for the cell and the plant.
  • Structure: Made of cellulose.