Transcript No Slide Title

Introduction to Cell Biology
Part 1:
•Cell Theory,
•Compartmentalization,
•Cell Type
•Cell Geography,
•Cell Size
The history of cell study
Robert Hooke, an
early microscopist,
in 1665, coined the
word “cell” after
looking at cork
through an early
“compound
microscope”.
The history of cell study
In 1675 Antonie van
Leeuwenhoek, an amateur
Dutch scientist, discovered
microscopic “animalcules”
in water. Looking at tooth
plaque, he first to discover
bacteria; 1000x smaller.
The history of cell study
Robert Brown, an
English botanist, in
1831, was the first to
call the dark, “nutlike” body in the
center of most of the
cells he observed a
"nucleus”. (Find them…)
The history of cell study
Theodor Schwan, a German botanist, in
1838, after viewing animal and plant
cells surmised that “all organisms
consist of one or more cells” and that
“cells are the basic unit of structure for
all organisms”.
The history of cell study
At about the same time, Mattias
Schleiden concluded from his
observations that “cells must be the
fundamental unit of life”.
The history of cell study
Rudolf Virchow, a German physiologist, in
1858, added the observation that “all cells
arise only from preexisting cells.” Which
supported the new theory of “biogenesis”,
being advanced by Pasteur, that “life
comes from life.”
The history of cell study
Cell Theory, 1860’s
1- All living things (organisms) are
composed of one or more cells.
2- Cells are the basic unit of organization
(structure and function) of organisms.
3- All cells come from preexisting cells.
An Essential Requirement for Life:
Why is Life Organized into Cells?
Why is Life Organized into Cells?
The ultimate goal of life is to … produce
copies of itself… because life is mortal
To do this, it is necessary to… have and pass
on information to the next generation
And to… to grow
Which requires the ability to… synthesize the
correct complex molecules
Requiring… chemical raw materials,
Requiring… the ability acquire matter,
Requiring… energy that must be harvested
energy from its environment,
Creating…wastes that must be gotten rid of.
The Solution!
…closed sac…
A cell.
Cell Types
Attributes of Cells
All cells can be separated into two
classifications based on their
attributes:
•Prokaryotic –
•Eukaryotic -
Cell Types
Attributes of Cells
Pro~kary~ote or Before~Kernal or Nut
Small cells without internal
membrane bound compartments
or structures. Their DNA forms a
loop rather than linear segments.
Eubacteria (new), archaebacteria
(old) are single celled prokaryotes.
Cell Types
Attributes of Cells
Eu~kary~ote or Good~Kernal or Nut
Cells having internal membrane bound
compartments and structures
(example~ nucleus containing linear
chromosomes ). The Animals, plants,
fungi and protists are multi and single
celled Eukaryotes.
Cell Geography: Eukaryote
Cell “Compartment”
Cell “nucleus”
Cell “cytoplasm”
Cell “cytoskeleton”
Cell “membrane”
Cell Geography: Prokaryote
Cell “Compartment”
nucleiod region (DNA)
Cell “cytoplasm”
Cell “membrane”
Cell “wall”
Capsule
Flagellum
Prokaryote vs. Eukaryote
Lacking compartments
vs.
Having many compartments
Cell size
Attributes of Cells
Most living cells range in size from
bacteria @ 1 µm to a hens egg @
50,000 µm. (µm ~ micrometer, 10-6 M)
Kind of Cell
Approximate Size
Bacteria (E. coli)
1 um
Red Blood Cell
8 um
Elodea epidermal cell
65 um
Amoeba
700 um
Hen's egg
50,000 um
Cell size
Cell size
Cell size
50 micrometers
written as µm
Cell size
5 micrometers (µm)
A false-color SEM photo of a Paramecium
Cell size
5 micrometers (µm)
A false-color SEM photo of mitochondria
Cell size
Basal Bodies of Cilia
0.5 micrometers (µm)
Cell size
Ribosome –
A cellular
Protein
Factory
0.05 micrometers (µm)