Transcript The Parts of the Cell

HISTORY OF CELL
BIOLOGY AND TYPES
OF CELLS
Pgs. 69-71
Cells
•Smallest unit that can perform life
processes
•Random Facts
• Average human is composed of 100 trillion cells
• It would take 50 cells to cover the dot of an “i” on
your paper
Who discovered cells?
1. Hooke, 1665
•Discovered cells while
looking at cork (plant
cells)
•Described them as tiny
boxes or rooms
•“cell” means little room
in Latin
•Thought cells only
existed in plants and
fungi
2. Leuwenhoek, 1673
•Observed pond scum
& found single-celled
organisms
•One of the first to
look at living cells
•He called them
“animalcules”
150-200 Year Gap….Not much was
discovered
• Between the Hooke/Leuwenhoek discoveries
and the mid 19th century, very little cell
advancements were made.
3. Schleiden, 1838
•German botanist
•Stated that all plants
are made up of cells
4. Schwann, 1839
•German Physiologist
•Stated that all
animals are made up
of cells
5. Virchow, 1858
•German Physician
•Studied cellular
pathology
•Concluded that
cells must come
from existing cells
Cell Theory
1. All living things are made up of
one or more cells
(Schleiden & Schwann 1838-39)
Cell Theory
2. Cells are the basic units of structure
and function in living things.
(Schleiden & Schwann 1838-39)
Cell Theory:
3. All cells are produced by the division of
existing cells
Cell Types and Common Parts
TPS: What differences do you
notice?
Type
of
Cells
Type of Cells
•Prokaryotic:
lack membrane-bound
organelles
• Unicellular
• Simple
• Capsule, cell wall, cell membrane
• No nucleus
• Cytoplasm (also in eukaryotes)
• Ribosomes (also in eukaryotes)
• Cilia, flagella (for movement) (also in eukaryotes)
• Oldest living cells
• Ex: bacteria
Prokaryotic
Type
of
Cells
Type of Cells
• Eukaryotic: contain a membrane-bound nucleus
and organelles
• Unicellular and multicellular
• More complex
•
Ex: Animal and plant cells
Size difference
Prokaryote
Eukaryote
All cells have the following in
common
1. Plasma (cell)
Membrane
•Acts as a barrier to the
outside world
•Semi-permeable:
allows only certain
materials to leave and
enter
All cells have the following in
common
2. Cytoplasm
•Gel-like substance
•Fills space in the cell
•Most reactions happen here
3. DNA
•Regulates cells function
•Stores and transfers genetic
information