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Cell Theory
• All living things are made up of cells.
• Cells are the smallest working units of all
living things.
• All cells come from preexisting cells
through cell division.
Definition of Cell
A cell is the smallest unit that is
capable of performing life
functions.
Organismes
Single cell
Multi cellular
(2+ cells)
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Red Blood Cell
Nerve Cell
Two Types of Cells
•Prokaryotic
•Eukaryotic
Cells
• There are two types of cells:
Prokaryotic
Eukaryotic
Prokaryotic
• Do not have
structures
surrounded by
membranes
• Few internal
structures
• One-celled
organisms,
(ex. bacteria)
http://library.thinkquest.org/C004535/prokaryotic_cells.html
Eukaryotic
• Contain organelles surrounded by membranes
• Most living organisms
Plant
http://library.thinkquest.org/C004535/eukaryotic_cells.html
Animal
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
“Typical” Plant Cell
http://waynesword.palomar.edu/images/plant3.gif
Cell Parts
Organelles
Surrounding the Cell
Cell Membrane
• Outer membrane of cell
that controls movement
in and out of the cell
• Double layer
http://library.thinkquest.org/12413/structures.html
Cell Wall
• Most commonly found
in plant cells &
bacteria
• Supports & protects
cells
http://library.thinkquest.org/12413/structures.html
Inside the Cell
Cytoplasm
• Gel-like mixture
• Surrounded by cell membrane
• Contains hereditary material
Endoplasmic Reticulum
• Moves materials around
in cell
• Smooth type: lacks
ribosomes
• Rough type (pictured):
ribosomes embedded in
surface
http://library.thinkquest.org/12413/structures.html
Ribosomes
• Each cell contains
thousands
• Make proteins
• Found on
endoplasmic
reticulum & floating
throughout the cell
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Produces energy through
chemical reactions –
breaking down fats &
carbohydrates
• Controls level of water and
other materials in cell
• Recycles and decomposes
proteins, fats, and
carbohydrates
http://library.thinkquest.org/12413/structures.html
Golgi Bodies
• Protein 'packaging
plant'
• Move materials within
the cell
• Move materials out of
the cell
http://library.thinkquest.org/12413/structures.html
Lysosome
• Digestive 'plant' for
proteins, fats, and
carbohydrates
• Transports undigested
material to cell
membrane for removal
• Cell breaks down if
lysosome explodes
http://library.thinkquest.org/12413/structures.html
Vacuoles
• Membrane-bound
sacs for storage,
digestion, and waste
removal
• Contains water
solution
• Help plants maintain
shape
http://library.thinkquest.org/12413/structures.html
Chloroplast
• Usually found in plant
cells
• Contains green
chlorophyll
• Where
photosynthesis takes
place
http://library.thinkquest.org/12413/structures.html
Cell Parts and Functions
Cilia
Short hair-like projections
Used for movement
Location: outside of cell
Flagella
Long whip-like tail
Used for movement
Location: outside of cell
Centrioles
• Organelle responsible for production of
spinal fibres during the division of the cell.
Nucleus
• Directs cell activities
• Separated from cytoplasm by nuclear
membrane
• Contains genetic material - DNA
Nuclear Membrane
• Surrounds nucleus
• Made of two layers
• Openings allow
material to enter and
leave nucleus
http://library.thinkquest.org/12413/structures.html
Cell Parts and Functions
Nucleolus (Nucleoli)
Makes ribosomes
Location: inside the nucleus
(dark spot)
Nuclear Membrane
Protects nucleus
Lets things in/out of nucleus (pores)
Location: around nucleus
cell
Nucleolus
• Inside nucleus
• Contains RNA to build
proteins
http://library.thinkquest.org/12413/structures.html
DNA
(Deoxyribonucleic
acid)
– genetic material
- It is called chromatin when it is
wound up.
A chromosome is
a structure
composed of DNA.
Chromosomes
• In the nucleus
• Is made up of DNA
• Contains the instructions for our traits and
characteristics.
• A lot of chromatin makes up chromosomes.
• Each chromosome
has a different form.
• Humanes have 46
chromosomes in the
form of 23 pairs found
in the nucleus of
each of our cells.
• Chromosomes are
particularly visibles
during the division
process of the cell.
• Different species
have different
numbers of
chromosomes.
- Humans have 46
- Chicken have 78
- Mosquito have 6
- Rice has 24
• Segments of DNA
determine a
particular hereditary
trait.
• A gene is on a
specific spot on
each chromosome.
Plant vs. Animal Cell
http://www.cellsalive.com/
Animal Cell
Plant Cell