Major Points
1. Cells: fundamental unit of life
2. Lipid membranes are essential to cell structure
3. Eukaryotes have subcellular compartments
Structure
Function
Prokaryotes
* Lipid cell membrane ("plasma membrane")
* No nucleus
* Circular DNA ("genome")
* Cytoplasm rich in ribosomes
* Surface projections (flagellae & pili)
Prokaryotes
DNA length = 1.5 millimeters (10-3 m)
Cell length = 1 micrometer (10-6 m)
Is this a problem?
Prokaryote = "before the nucleus"
Eukaryote = "true nucleus"
Eukaryotic Organelles
Nucleus
- Nucleolus
Plastids
- Chloroplast (plants only)
- Mitochondrion
Vacuole (plants only)
Endoplasmic Reticulum
- Rough E. R.
- Smooth E. R.
Movement
* Plant cells do not move
* Animal cells can move
- Important in normal growth--e.g., phagocytosis ("cell
eating")
- Important in development
Important Issues
1. How do cells express their genetic information?
2. How do they convert food to useful energy?
3. How are proteins targeted to cellular locations?