Cell Structure
Jan 20, 2016
Cell Structure
Cell Theory
States the following:
1. All organisms are made up of cells (one or more)
2. All cells come from preexisting cells (cell reproduction)
3. All cells are essentially the same in chemical composition
Prokaryotic vs Eukaryoticcells
Prokaryote vs. EukaryoteProkaryote Eukaryote
No nucleus Nucleus
No membrane bound organelles
Membrane bound organelles
Only bacteria All other cells
Evolved 3.5 billion ya Evolved 1.5 billion ya
About 1-10 micrometers in size
About 2-1000 micrometers in size
Can live w/out oxygen Requires oxygen to live
Components of an Animal Cell
Components of a Plant Cell
Elodea cells
Onion cells stained
Cheek cells
We will use the following analogy…• Think of the cell as a city
Let’s Start from the Inside…The Nucleus (Animal and Plant Cells
A &P)
The Central Command Center
Information (DNA)
Ribosomes-factories• Ribosomes
- Each cell contains thousands- Miniature 'protein factories'- Composes 25% of cell's mass- Stationary type: embedded in rough endoplasmic reticulum- Mobile type: injects proteins directly into cytoplasm
Rough/Smooth ER and Ribosomes (Animal and Plant Cells A &P)
• Where proteins and lipids are made
• Some molecular traffic directed by ER
Internal transport systems
City streets
Golgi Bodies (Animal and Plant Cells A &P)
• Packages cell proteins & lipids
• For cellular export
Post Office
Mitochondria (Animal and Plant Cells A &P)
• Produces energy (ATP) for the cell to use
Power Plant
Chloroplasts (only in Plant Cells)
• Where photosynthesis occurs
• Sugars are made
A secondary Power Plant
solar cells (only in plants)
Lysosome (Animal and Plant Cells A &P, Mostly Animal)
• Uses digestive enzymes to break down macromolecules
Garbage Dump
Treatment plant
Vacuoles (Animal and Plant Cells A &P)
• Fluid filled space, used for storage, digestion, water retention (in plants)
Warehouse
Cytoplasm or Cytosol (Animal and Plant Cells A &P)
• Mainly water, forms the “body” of the cell
Air of the city
Cytoskeleton (Animal and Plant Cells A &P)
• Aid in cell movement (actin)
• Also help in protein/lipid movement inside the cell (microtubules) and cell support
Support rods
Cell Wall (only in Plant Cells)
• Provide rigidity for structure and support
• Contains cellulose
Outer Wall
Membrane Structure
• Fluid like