Download The Cell Theory

The Cell Theory
and
Cell Structures
The Cell Theory
• The Cell Theory is a widely accepted
explanation of the relationship between cells
and living things.
– It refers to the idea that cells are the basic unit of
structure in every living thing.
• The observations of five scientists led to the
development of the cell theory
Introductory Video
click to play
Scientists of The Cell Theory
• Robert Hooke
(1665)
– Studied cork cells and
noticed that they looked
like jail cells, thus giving
them the name Cells.
http://en.wikipedia.org/wiki/Image:Cork_Micrographia_Hooke.png#file
Scientists of The Cell Theory
• Anton van Leeuwenhoek
(1680)
– First to witness living
cells, bacteria and
protozoa, under a singlelens microscope.
– Named the moving
organisms he saw
animalcules, “little
animals”.
http://farm4.static.flickr.com/3141/2762756941_ff35517502.jpg
Scientists of The Cell Theory
• Matthias Schleiden (1838)
– A German botanist who discovered that plant
parts are made of cells.
– Brought the nucleus to popular attention and its
importance in the function of a cell.
• Theodor Schwann (1839)
– A German zoologist who discovered that animal
parts are made of cells.
• Rudolph Virchow (1855)
– A German physician who stated that all living cells
come only from other living cells.
Cell Theory Timeline
1665 1680s
1838 1839 1855
The Cell Theory
1. All living things are made of cells.
2. The cell is the basic unit of structure and
function in living things.
3. All cells come from pre-existing cells.
The cell theory holds true for all living things,
no matter how big or small, how simple or
complex.
Cell Structures
• In many ways cells are like factories that
produce goods.
– Take in raw materials, use them to build products
(proteins and energy), package the products and
transport them to different parts of the cell.
• There are two types of cells that make up all
living things:
– Prokaryotic Cells
– Eukaryotic Cells
Prokaryotic Cells
• NO nucleus
• No membrane bound
organelles.
• Single celled
organisms
– Bacteria
Kingdoms
– Archaebacteria
http://scienceblogs.com/
Eukaryotic Cells
• Has a nucleus!!!!
• Organelles are enclosed
in their own membrane.
• Large and complex.
• Multicellular organisms
–
–
–
–
Plants
Animals
Protists
Fungi
Kingdoms
Prokaryote vs. Eukaryote Cells
• No nucleus
• No membrane
bound
organelles
• Single Celled
Organisms
• True nucleus
• Contains
DNA
• Similar
Metabolism
• Membrane
bound organelles
• Multicellular
Prokaryote or Eukaryote
Nucleus
Nucleus
Eukaryote
Prokaryote
Prokaryote
Eukaryote
Cell Structures
Organelles – tiny cell structures that carry out
specific functions within the cell (“little organs”.
Organelle
Nucleus
Function
Directs all of the cell’s activities, Control
Center.
Cell Membrane
Selectively permeable membrane that
allows substances to enter and leave the cell.
Chromosomes
Contain DNA and pass on genetic
information to new cells (X).
Mitochondria
Powerhouse of the Cell – converts resources
into energy.
Chloroplasts
Captures energy from sunlight to make food
(Plants ONLY)
Vacuole
Cytoplasm
Cell Wall
Stores food, water and waste.
Allows movement of materials around the
cells and supports other cell structures.
Surrounds the cell membrane and keeps
plant cells rigid and upright.
Plant Cell – (Square/boxed)
Nuclear Membrane
Nucleus
Mitochondria
- “Power house”
- Control Center
Chromosomes
Cell
Membrane
- Colored Bodies
- Selectively Permeable
Cell Wall
- Plants ONLY!
Cytoplasm
Chloroplasts
- Plants ONLY!
Vacuole
- Storage
Animal Cells – (Round)
Nucleus
Mitochondria
- Control Center
Chromosomes
- Colored Bodies
- “Power house”
Vacuole
- Storage
Cell Membrane
- Selectively Permeable
Nuclear
Membrane
Cytoplasm
Plant vs. Animal Cells
Organelle
Plant Cell
Animal Cell
Cell Shape
Square
Round
Cell Membrane
Yes
Yes
Cell Wall
Yes
Mitochondria
Yes
Yes
Nucleus
Yes
Yes
Chromosome
Yes
Yes
Chloroplasts
Yes
Vacuole
Yes
Yes