Cell Structure
& Function
http://koning.ecsu.ctstateu.edu/cell/cell.html
Cell Theory
• All living things are made of cells.
• Cells are the smallest units of life
• All cells come from preexisting cells.
Cell Theory Scientists
• Hooke – named cells after viewing cork
under a microscope
• Leeuwenhook – saw living cells and called
them “animalcules”
• Schwann – concluded that animals were
made of cells
• Schleiden – concluded that plants were
made of cells
• Virchow – determined that cells only came
from pre-existing cells
Definition of Cell
The smallest unit capable of life.
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Red Blood Cell
Nerve Cell
Two Types of Cells
•Prokaryotic
(leave space)
•Eukaryotic
Prokaryotic
• No membrane
bound structures
• No organelles or
nucleus
• One-celled
organisms,
Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
Eukaryotic
• Contain organelles surrounded by membranes
• Most living organisms, single or multi-celled
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
Eukaryotic
Organelles
Surrounding the Cell
Cell Membrane
• All cells
• Outer part of cell that
controls movement in
and out of the cell
• Made of a double layer
called Phospholipid
bilayer
http://library.thinkquest.org/12413/structures.html
Cell Wall
• Found in eukaryote
plant & some
prokaryotes only
• Supports cell
http://library.thinkquest.org/12413/structures.html
Inside the Cell
Nucleus
• Eukaryotes only
• Directs cell activities
• Separated from cytoplasm by nuclear
membrane
• Contains DNA (genetic instructions)
Nuclear Membrane
•
•
•
•
Eukaryotes only
Surrounds nucleus
Made of two layers
Openings allow RNA
to enter and leave
nucleus
http://library.thinkquest.org/12413/structures.html
Nucleolus
• Eukaryotes Only
• Inside nucleus
• Makes ribosomes
http://library.thinkquest.org/12413/structures.html
Cytoplasm
• All cells
• Gel-like mixture that fills cell
• Site of some chemical reactions
Endoplasmic Reticulum
• Eukaryotes only
• Moves materials around
within cell to help
assemble proteins and
lipids
• Smooth type: lacks
ribosomes
• Rough type (pictured):
ribosomes embedded in
surface
http://library.thinkquest.org/12413/structures.html
Ribosomes
• All Cells
• Each cell contains
thousands
• Make proteins
• Found on ER &
floating throughout
the cell
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Eukaryotes Only
• Produces energy (ATP)
from sugar (glucose)
through cell respiration
http://library.thinkquest.org/12413/structures.html
Golgi Bodies
• Eukaryotes Only
• Protein “package and
ship”
• Move materials in
and out of the cell
(like the post office)
http://library.thinkquest.org/12413/structures.html
Lysosome
• Eukaryotes only
• Digests/Destroys worn
out parts, proteins, fats,
and carbohydrates
• Cell breaks down if
lysosome explodes
http://library.thinkquest.org/12413/structures.html
Vacuoles
• Eukaryotes only
• Membrane-bound
sacs for storage
(especially water in
plant cells)
• Help plants maintain
shape
http://library.thinkquest.org/12413/structures.html
Chloroplast
• Eukaryotic plant cells
only
• Contains green
chlorophyll
• Site of photosynthesis
(where light energy is
converted to
carbohydrate energy)
http://library.thinkquest.org/12413/structures.html
Centriole (Centrosome)
• Eukaryotic Animal
Cells ONLY
• Helps with cell
division
Microtubule & Microfilament
• Eukaryotic Cells
only
• Make up
cytoskeleton
• Interior Support
Strike through Nuclear Pores
and add…
• Cilia
– All cells (optional)
– Hair-like, for
movement
• Flagella
– All cells (optional)
– Tail-like, for
movement
Group Project – The ____ is like
a _____, because _______.
• Make analogies for
the following
organelles
– Nucleus
– Nucleolus
– Endoplasmic
reticulum
– Golgi
– vacuole
– Cytoplasm
– Ribosomes
– Cytoskeleton
– Chrolorplast
– Centriole
– Cell membrane
– Lysosomes
– Mitochondria
– Cell wall