Transcript Cell Structure & Function - Mrs. Pace's Science Site

Cell Structure
& Function
7/20/2015
4
Definition of Cell
A cell is the smallest unit that is
capable of performing life
functions.
Cell Theory (Teoría)
1. All living things are made up of cells.
2. Cells are the smallest working units of all
living things.
3. All complex cells come from preexisting
cells through cell division.
Two Major Types of Cells
•Prokaryotic- “simple” cells
•Eukaryotic- “complex” (complejo) cells
•Most living things you are familiar with (including
humans) have eukaryotic cells.
Prokaryotic
• Do not have a
nucleus or other
organelles
• One-celled
organisms,
bacteria, etc.
Bacteria cell in
the process of
reproducing
(dividing)
Eukaryotic
• Contain a nucleus and other organelles (smaller parts)
surrounded by membranes
• Most living organisms have these type of cells
Plant cell
Animal cell
Prokaryote vs. Eukaryote
Prokaryote:
Both:
Eukaryote:
-are living
-has no
organelles
(no nucleus)
-have DNA
-are cells
-has organelles
(has a nucleus)
“Typical” Animal Cell
“Typical” Plant Cell
Cell Parts
Organelles: “little organs”
Think of a cell as a factory- lots of separate people,
departments, and machines that each have their own
task, but they work together to get a job done.
Surrounding the Cell
Cell Membrane
• Cell Membrane (like
factory doors and gates):
surround the cell
• provide communication
with other cells
• control entrance and exit
of materials, thereby
maintaining internal
balance
Cell Wall (plants only)
•
Cell Wall (like factory outer walls): further
protects the cell and provides strength
Inside the Cell
Nucleus
• Cell nucleus (like the factory
central office): the “boss” of
the cell
• Directs all cell activities
• Separated by a nuclear
membrane (it’s own “cell
wall”)
• Contains genetic material DNA
Cytoplasm
• Cytoplasm (like the
factory floor): contains
and carries all other
organelles
• Gel-like material; the
“goop” of the cell
Endoplasmic Reticulum
• Endoplasmic reticulum
(like factory conveyor
belts): move materials
around in cell
• Smooth type: has no
ribosomes
• Rough type (pictured): has
ribosomes in surface
Ribosomes
• Ribosomes (like the
factory assembly line):
put together proteins
• Each cell contains
thousands
• Found on reticulum and
floating throughout the
cell
Mitochondria
• Mitochondria (like the factory
generator): the “power plant”
of the cell
• Produces energy through
chemical reactions –
breaking down fats &
carbohydrates
Golgi Bodies (Apparatus)
• Golgi bodies (like the
factory packing and
shipping department): the
UPS or Fed-Ex of the cell
• Transports and packages
proteins and other
materials in the cell
– Moves materials within the
cell
– Moves materials out of the
cell
Lysosome
• Lysosomes (like the factory
waste management
dpartment): the “wrecking
crew” and “trash can” of
the cell
• Transports undigested
material to cell membrane
for removal
• Cell breaks down if
lysosome explodes or
ruptures 
Vacuoles
• Vacuoles (like factory
storage/factory water
tower): the “storage
container” of the cell
• Sacs for storage,
digestion, and waste
removal
• Help plants maintain
shape- very large in
plants
Chloroplast (plants only)
• Chloroplasts (like factory
solar energy plants):
turns energy from the
sun (with CO2 and
water) into food
• Contains green
chlorophyll
• Where photosynthesis
takes place
Today’s Assignment
• Cell Analogy Project
(cell structures)
How about
an
example?
• Your cell analogy can be a factory, a store, a
school, a garage.
• You may choose a plant or animal cell
• 100 pts possible