Download file

9/16/2012
Types of cells
• Prokaryotes
– Simple, primitive cells that lack a
nucleus and membrane-bound
organelles
– Ex. Bacteria
• Eukaryotes
– Complex cells that contain a
nucleus and membrane-bound
organelles
– Ex. plant, animals, fungi, protists
Prokaryotes v. Eukaryotes
• Organelle comparisons
Prokaryotes v. Eukaryotes
• Size comparisons
– most bacteria
Animal cell
Bacterial cell
• 1-10 microns
– eukaryotic cells
• 10-100 microns
POINTS OF REFERENCE
micron = micrometer = 1/1,000,000 meter
diameter of human hair = ~20 microns
The Many JOBS of a Cell
WHY study cells?
• Bodies are made up of cells
• Cells do all the work of life!
• gas exchange
– O2 in; CO2 out
• eat
– take in & digest food
• make energy
– ATP
• build molecules
– proteins, carbohydrates, fats, nucleic acids
• remove wastes
• control internal conditions
– homeostasis
• respond to external environment
• build more cells
– growth, repair, reproduction & development
1
9/16/2012
THREE Primary Jobs
ATP (Adenosine triphosphate)
• Energy production
– need energy for all activities
– need to clean up waste produced
while making energy
Organelles
• Literally translates to “tiny organs”
• Do the work of cells
– each structure has a job to do
• keeps the cell alive and thus keeps the organism alive
• Protein production
– proteins do all the work in a cell,
so we need lots of them
• Reproduction
– for growth
– to replace damaged or
diseased cells
Cell Membrane
• Function
• Making energy
– separates cell from
outside
– controls what enters or
leaves cell
– to fuel daily life & growth,
the cell must…
•
•
•
•
take in food & digest it
take in oxygen (O2)
make ATP
remove waste
• O2, CO2, food, H2O,
nutrients, waste
– recognizes signals from
other cells
• allows cells to
communicate
– organelles that do this work…
•
•
•
•
cell membrane
lysosomes
vacuoles & vesicles
mitochondria
• Structure
– double layer of fat
• phospholipid bilayer
– receptor molecules
• proteins that receive
signals
Mighty the Mitochondria
Vacuoles & Vesicles
Food & Water Storage
• Function
– moving material around cell
– storage of water, nutrients,
and minerals
• Animal cells
– food vacuole
small food
particle
• Structure
lysosome filled w/
digestive enzymes
– membrane sac
ENDOCYTOSIS
vesicle
• Contain food reserves
such as sugars and
mineral salts which are
used by the cytoplasm
when required
– contractile vacuole
EXOCYTOSIS
vesicles filled w/
digested nutrients
• Mainly found in protists
• Pumps water out to
maintain osmotic
homeostasis in
freshwater environments
2
de/speci
sorders.
9/16/2012
Food & Water Storage
Lysosomes
• Plant cells – central vacuole
• Function
– digest food
– Larger than animal vacuoles
– Helps keep plants from “drying out”
• used to make energy
– clean up & recycle
CENTRAL
VACUOLE
• digest broken organelles
• Structure
– membrane sac of digestive enzymes
http://highered.mcgrawhill.com/sites/0072495855/stu
dent_view0/chapter2/animati
on__lysosomes.html
Lysosomes and YOU!
Mitochondria
• Degrade tissues during
embryonic development
• Function
– make ATP energy from cellular respiration
• sugar + O2  ATP
• fuels the work of life
• Structure
– double membrane
• Lysosomal Storage Diseases
– Tay-Sachs
– Pompe’s
Plants make Energy in TWO ways
Mitochondria & Chloroplasts
• Chloroplasts
– make energy + sugar from
sunlight
• photosynthesis
• sunlight + CO2  ATP &
sugar
– ATP = active energy
– sugar = stored energy
» build leaves & roots &
fruit out of the sugars
MITOCHONDRIA (in BOTH plants AND animals)
• Mitochondria
– make energy from sugar + O2
• cellular respiration
• sugar + O2  ATP
3
9/16/2012
PROTEINS do all the work!
• Making proteins
– to run daily life & growth, the cell must…
• One of the major job of
cells is to make proteins,
because proteins do all
the work.
• read genes (DNA)
• build proteins
– structural proteins (muscle fibers, hair, skin, claws)
– enzymes (speed up chemical reactions)
– signals (hormones) & receptors
– organelles that do this work…
•
•
•
•
nucleus
ribosomes
endoplasmic reticulum (ER)
Golgi apparatus
Nucleus
• Function
– control center of cell
– protects DNA
• instructions for building
proteins
• Structure
– nuclear membrane
– nucleolus
• ribosome factory
Ribosomes
• Function
– protein factories
– read instructions to build
proteins from DNA
• Structure
– some free in cytoplasm
– some attached to ER
Ribosomes on ER
– chromosomes
• DNA
Endoplasmic Reticulum
• Function
– works on proteins
• helps complete the proteins after ribosome builds them
– makes membranes
• Structure
– rough ER
• ribosomes attached
• works on proteins
– smooth ER
• makes membranes
Golgi Apparatus
a.k.a. Golgi body
• Function
– finishes, sorts, labels &
ships proteins
• like UPS headquarters
– shipping & receiving
department
– ships proteins in
vesicles
• “UPS trucks”
• Structure
– membrane sacs/tubes
• Resemble a stack of
pancakes
4
9/16/2012
Centrioles
• Making more cells
– to replace, repair & grow, the
cell must…
• copy their DNA
• make extra organelles
• divide the new DNA & new
organelles between two new
“daughter” cells
• Function
– help coordinate cell division in ANIMAL cells
• Structure
– one pair in each ANIMAL cell
– organelles that do this work…
• nucleus
• centrioles
Nucleus
• Contents are
copied and then
divided into two
new cells.
5