INTRODUCTION TO CELLS
Robert Hooke
naturalist, philosopher, inventor, architect....
(July 18, 1635 - March 3, 1703)
He was the first person to use the term “cells”.
Anton van Leeuwenhoek
1632-1723
 perfected the
simple
microscope
 He discovered
bacteria in
1674 and four
years later, he
discovers
protozoa.
Cell Theory
Matthias Schleiden Theodore Schwann
all plants are made
of cells
all animals are made
of cells
Cell Theory
Rudolf Virchow
all cells came from
pre-existing cells
Cell Theory
Matthias
Schleiden
concluded that all
plants are made of
cells (1838)
Theodore
Schwann
concluded that all
animals are made
of cells (1839)
Rudolf Virchow
concluded that all
cells came from
pre-existing cells
(1855)
Cell Theory
• all living things are made up of cells
• cells are the basic units of structure and function in
an organism
• new cells are produced from existing cells
Cell Specialization
Cells in
organisms are
specialized to
perform different
tasks.
Photos from
Biology,
Prentice Hall
The Levels of Organization
Multicellular organisms are arranged from simple to
complex according to their level of cellular grouping.
Simple
Complex
cell
tissue
organ
organ
system
organism
Levels of Organization
What is the benefit of being made of all of
these cells?
Level
Function
Organ
system
Different organs
function together
Organ
Different tissues
function together
Tissues
Cells
Similar cells
function together
Cells can perform
special jobs
Example
Nervous System
Brain
Nervous Tissue
Neuron
Cell Types
PROKARYOTE
EUKARYOTE
 No membrane-bound
organelles (nucleus)
 Small ribosomes
 Most cells are 1 -10
μm in size
 Evolved 3.5 billion
years ago
 Found only in
Archaebacteria and
Eubacteria Kingdoms
 Has membranebound organelles
(nucleus)
 Larger ribosomes
 Cells can be between
2 - 1,000 μm in size
 Evolved 1.5 billion
years ago
 Includes Protista,
Fungi, Plantae and
Animalia Kingdoms
A unit of length equal to one
thousandth (10-3) of a millimeter
Cell Type: Prokaryotes
Prokaryotes, which includes all bacteria,
are the simplest cellular organisms. They
have genetic material but no nucleus.
Typical bacteria cell
Cell Types: Eukaryotes
Eukaryotic cells
contain a membranebound nucleus and
numerous membrane
-enclosed organelles
(e.g., mitochondria,
lysosomes, Golgi
apparatus) not found
in prokaryotes.
Examples of Eukaryotes
Different Types of Cells
Prokaryotic
no nucleus
Eukaryotic
nonucleus
nucleus
nucleus
small ribosomes larger
ribosomes larger ribosomes
small ribosomes
no organelles
noorganelles
organelles
small
small
very small 1-10um very
organelles
small 2-1000um
only in bacteria protists, fungi,
protists, fungi,
only in bacteria
plants, animals
plants, animals
What Are the Parts of Cells
Both prokaryotic
and eukaryotic
cells have some
things in common.
nuclear
cell membrane
ribosomes
cytoplasm
material
All cells have
¤ cell membrane
¤ cytoplasm
¤ ribosomes
¤ nuclear material
PHOSPHOLIPID Figure 7-12 The Structure of the
Cell Membrane
BILAYER
Section 7-3
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
of cell
(cytoplasm)
Protein
channel
Lipid bilayer
Venn Diagrams
Section 7-2
Prokaryotes
Eukaryotes
Cell membrane
Contain DNA
Animal Cells
Centrioles
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Figure 7-5 Plant and Animal Cells
Section 7-2
Nucleolus
Nucleus
Ribosome
(attached)
Nuclear
envelope
Ribosome
(free)
Cell
Membrane
Mitochondrion
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi apparatus
Animal Cell
Figure 7-5 Plant and Animal Cells
Section 7-2
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum
Plant Cell
Golgi
cytoplasm:
nucleus:
chloroplast:
vacuole:
ribosomes:
mitochondria:
cell
endoplasmic
membrane:
wall:
complex:
sac-like
controls
outer
semi-liquid
manufacture
capture
reticulum:
convert
layer
most
in
material
cell
energy
structure
proteins
chemical
regulates
plant
transportation
packages
processes,
cells,
from
that
energy
that
what
proteins
support
sunlight
fills
stores
system
enters
contains
stored
theand
cell
hereditary
water,
in
and
protection
throughout
food
convert
leaves
salts,
intoinformation
the
the
ATP
it
foods,
into
cell,
cell
(cellular
etc
(DNA)
chemical
respiration
protection
energy
and
occurs
support
(food),
here)
(photosynthesis occurs
here)
Parts of a plant cell
cytoplasm
endoplasmic
reticulum
nucleus
chloroplast
vacuole
golgi complex
ribosomes
mitochondria
cell membrane
(p. 175)
cell wall
Plant Cell
cytoplasm
endoplasmic
reticulum
nucleus
chloroplast
vacuole
golgi complex
ribosomes
mitochondria
cell membrane
(p. 175)
cell wall
Cell Organelles
Cell Membrane
Mitochondria
Chloroplast
Endoplasmic Reticulum
Nucleus
Vacuole
Lysosome
Golgi Body
Ribosome
 Animal
Cell Wall
 Plant
Cell Video Q’s
How did they grow the little girl’s skin?
Can an organism live with only one cell?
Why did Hooke call the objects he viewed with
microscope cells?
If all plants are made of cells, why do you
think they vary in size and appearance?