1. Cells

2. Cell Theory Cells are the basic units of living organisms.
The cell theory states that:
All living things are made of one or more cells.
Cells are the basic unit of structure and function in living things.
All cells come from other cells.

3. Biology, 9th ed,Sylvia Mader
Chapter 04
Cell Structure and Function
Sizes of Living Things
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0.1 nm
1 nm
10 nm
100 nm 1 m 10 m
100 m
1 mm
1 cm
0.1 m
1 m
10 m
100 m
1 km
protein
chloroplast
plant and
animal
cells
mouse
rose
frog egg
amino
acid
virus
ostrich
egg
most bacteria
human egg
ant
atom
blue whale
human
electron microscope
light microscope
human eye

4. Characteristics of All Cells
A surrounding membrane
Cytoplasm – cell contents in thick fluid
Organelles – structures for cell function
Control center with DNA

5. Classification of Life
Prokaryotic Eukaryotic

6. Cell Types Two categories: 1. Prokaryotic cells
- Unicellular organisms such as bacteria are examples of prokaryotes.
2. Eukaryotic Cells
- All other cells are these.

7. Biology, 9th ed,Sylvia Mader
Chapter 04
Cell Structure and Function
Prokaryotic Cells
Lack a membrane-bound nucleus
Structurally smaller and simpler than eukaryotic cells (which have a nucleus).
Most ancient and abundant type of cells
Prokaryotic cells are placed in two taxonomic domains:
Bacteria
Archaea
Live in extreme habitats

8. The Structure of Bacteria
Extremely small - 1–1.5 μm wide and 2–6 μm long
Occur in three basic shapes:
Spherical coccus,
Rod-shaped bacillus,
Spiral spirillum (if rigid) or spirochete (if flexible).
spirillum
spirochete
bacillus
coccus

10. Prokaryotic Cell Structure
Have a simple cell structure

11. Prokaryote Cells Parts
capsule: slimy outer coating
cell wall: tougher middle layer
cell membrane: delicate inner skin

12. Prokaryote cells are simply built
cytoplasm: inner liquid filling
DNA in one big loop
flagella: for swimming
ribosomes: for building proteins

13. Video Recap
Bacteria