Cell Types and Cell
Organelles
Cell Theory
 Cell Theory:
 All living things are composed of cells
 Cells are the basic units of living things.
 New cells arise only from preexisting cells.
 Microscopes revealed the presence of cells and show
their detailed structure.
 Animal and Plant cells contain organelles
 Organelles are “little organs”: small bodies that
have a specific structure and function
Important Scientists for Cells
1665: Robert Hooke: Came up with the name cells
while observing cork from a tree
1674: Anton van Leeuwenhoek: Used singlelensed microscope to observe pond water
1838: Matthias Schleiden:Discovered that all
plants are made of cells
1839: Theodore Schwann: Discovered all animals
are made of cells
Prokaryotic Cells vs. Eukaryotic Cell
 Are extremely small
 Do not have a nucleus
 Have a cell wall with or
without peptidoglycan
 Lack membrane bound
organelles
 Bacteria are prokaryotic cells
 Are larger cells
 There is a nucleus present
 Cellulose cell wall (plants only)
or chitin (fungi only)
 Contain many organelles
 Have larger ribosomes
 Everything except bacteria
The Nucleus- The Brain of The Cell
Structure
 Large organelle surrounded
by a nuclear membrane
 Contains pores
Functions
 Contains the DNA
(chromosomes) and
nucleolus
 Controls cell’s activities
 Nucleolus makes ribosomes
Mitochondria: The Powerhouse
Structure
 Usually oval, with a double
membrane
 Inner membrane (cristae)
within outer
membrane….inside is called
the matrix.
Function
 The site of cellular respiration,
where ATP is made in both plants
and animals
Important Info
 Found in large numbers in cells
requiring lots of energy.
 Powerhouse of the cell
Chloroplasts - The Bakery
Structure
 Small , flattened
structure found in plants.
 Surrounded by double
membrane; has inner
membranes inside
(thylakoid membranes)
 Contain chlorophyll
Function
 Site of photosynthesis
(Change light energy into glucose )
Endosymbiotic Theory
‘Where did organelles come from?”
Chloroplasts and Mitochondria are
particularly specialized organelles as
they contain their own DNA and have
complex membrane structures. Because
of these complexity of these cells,
scientists have a theory that these
organelles are actually descendents of
early prokaryotic cells that were
engulfed (or taken in) by early
eukaryotic cells.
Ribosomes- The Factories
Structure
 Very small organelle
 Can be free floating
or can be attached
to the ER
Function
 Site where proteins
are made (protein
synthesis)
Endoplasmic Reticulum (ER)
-The highway of the cell
Structure
 System of membranes
(channels and tubular
canals) enclosing a fluid
filled space
 Surface covered with
ribosomes
Function
 Transports proteins which
have been made in the
ribosomes
Smooth ER
 No ribosomes present
 Makes and transports
lipids.
 Detoxify drugs in the
liver.
& Rough ER
 Ribosomes are attached
 Makes proteins for the cell
to export
 Modifies the content
 Forms vesicles then carries
contents to the Golgi
The Golgi Apparatus - The UPS
Structure
 Group of smooth endoplasmic reticulum that have
flattened sacs
 Vesicles are often seen at the edges
Functions
 Modifies, sorts and packages substances that are
produced by cells (mainly proteins and glycoproteins)
 Makes lysosomes
Lysosome - The Garbage
Storage Bin
Structure
 Round organelle surrounded by a
membrane
Function
 Contains digestive enzymes that
are used to
 Breakdown macromolecules into
small molecules the cell can use
(recycling)
 digest invading cells or to
destroy the cell if it needs to
be replaced (so it’s also called a
Suicide Bag!)
Vacuoles - Storage Tank
Structure
 Membrane enclosed sacs
for storage.
Function
 Stores materials such as
water, salts, proteins
and carbohydrates
Important Info
 Plant cells contain one
large central vacuole
which provides support in
the form of Turgor
Pressure
Centrioles- the ushers
Structure
 Paired structures located
near nucleus
 Only visible when cell is
ready to divide
Function
 Helps organize cell division
Important Info
 Not found in plant cells
Cell Membrane : Gatekeeper of the Cell
Also called the plasma membrane
Structure
 Found on the surface of animal
cells and just inside cell wall of
plants
 Made of proteins and lipids
Functions
 Regulates what goes into and
out of the cell
 Also provides protection and
support
 Has receptor molecules to
respond to chemicals
Cell Wall: Supporter of Plant Cells
Structure
 A rigid structure that
surrounds plant cells.
 Made mainly of cellulose (a
carbohydrate)
Functions
 Supports and strengthens
plant cells
 Plant cells have a cell wall in
addition to a cell
membrane.
The Cytoskeleton- The Backbone
Structure
 Supporting structure
and transport system
 Network of protein
filaments
Function
 Helps the cell to keep
its shape
 Also helps cell move
using things called
microfilaments and
microtubules
Plant
vs.
 Cell wall made of
cellulose
 Have one large central
vacuole
 Contain Chloroplasts
Animal
 Have no cell wall
 Have many small
vacuoles
 No chloroplasts
12. Plant Cell (Top) – pg. 175
Nucleolus
Nucleus
Smooth
endoplasmic
reticulum
Nuclear envelope
Ribosome (free)
Rough endoplasmic
reticulum
Ribosome
(attached)
Golgi
apparatus
Cell wall
Cell membrane
Chloroplast
Mitochondrion
Vacuole
12. Animal Cell (Bottom) – pg. 175
Nucleolus
Smooth endoplasmic
reticulum
Nucleus
Nuclear envelope
Rough
endoplasmic
reticulum
Ribosome (free)
Cell membrane
Ribosome
(attached)
Centrioles
Mitochondrion
Golgi
apparatus
(On the back)
Bacteria Cell – pg. 472
Peptidoglycan
Cell
Wall
Flagellum
Cell
Membrane
DNA
Ribosomes
Pili