Lesson 2: Cells, Organelles, and the Cell Membrane

The cell is the basic unit of life. Cell theory says all living things are made of cells, the cell is the smallest unit of life, and all cells come from other cells.

Prokaryotic vs Eukaryotic

• ●Prokaryotic: small, simple, no nucleus, DNA floats free. Bacteria are prokaryotes.
• ●Eukaryotic: bigger, has a nucleus and membrane-bound organelles. Plants, animals, fungi, and protists are eukaryotes.

Main Organelles and Their Jobs

• ●Nucleus: control center, holds the DNA
• ●Mitochondria: powerhouse, makes energy (ATP) through cellular respiration
• ●Ribosomes: build proteins
• ●Endoplasmic reticulum: transport system that moves materials
• ●Golgi apparatus: packages and ships proteins
• ●Chloroplasts: do photosynthesis (plant cells only)
• ●Vacuole: storage, large in plant cells
• ●Cell wall: stiff outer layer for support (plants, fungi, bacteria, not animals)