Lesson 2 of 12
🨠 Cells: Building Blocks of Life
What You'll Learn
- Understand that all living things are made of cells
- Identify key organelles and their functions
- Compare plant and animal cells
Cell Theory
Three core principles of cell theory (established 1838–1858):
- All living things are made of one or more cells
- The cell is the basic unit of life
- All cells come from pre-existing cells
Key Organelles
- 🐵 Cell membrane — controls what enters/exits the cell
- 🧠 Nucleus — the control center; contains DNA
- ⚡ Mitochondria — produces energy (ATP) via cellular respiration; "powerhouse of the cell"
- 🔂 Ribosomes — build proteins from amino acids
- 🕐 Endoplasmic reticulum (ER) — transports proteins and lipids
- 🛍 Golgi apparatus — packages and ships proteins out of the cell
- 🔎 Vacuole — stores water, nutrients, waste
- 🌿 Chloroplasts — plants only — site of photosynthesis
- 🠲 Cell wall — plants only — rigid outer layer for structure and protection
🨠 Virtual Lab: Cell Organelle Explorer
Click any organelle on the diagram to see its name and function. Toggle between plant and animal cell!
Click an organelle to learn about it.
Quick Check
Which organelle is called the "powerhouse of the cell"?
Which structure is found in plant cells but NOT animal cells?