Transcript CELLS - Hudson City School District

CELLS
Cell Structure and
Function
Cinda Sheldon
SIZE COMPARISONS
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REPRESENTS 10 MICRONS
0.5-.05 microns-VIRUS
O.5-1.5 microns-BACTERIA
5 microns-RED BLOOD CELL
5-8 microns-LYMPHOCYTE
60 microns-HUMAN SPERM
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CELL STRUCTURE
 GET
OUT
YOUR
COLORED
PENCILS
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Prokaryotic Cell (bacteria)

No true nucleus
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Nucleoid

Coiled DNA-not in a membrane
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Capsule

Sticky, helps
the cell
adhere to
surfaces
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Prokaryotic

Here’s
streptococcus,
anthrax, and
meningitis
bacteria
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Eukaryotic

DO HAVE A TRUE
NUCLEUS
WITH A MEMBRANE
– Plants
– Animals
– Fungi
– Protists
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Eukaryotic Cells

Have a true nucleus bound by a
membrane
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EUKARYOTIC CELLS

You will make
an edible cell
model block
day – Nov. 29
+ 30
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NUCLEUS
 Houses
the
genetic
material:
DNA
 Control
center
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The Nucleus

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Nuclear
Envelope-double
membrane with
pores to let
materials in and
out
DNA
 Chromatin
= DNA
attached to
protein as
long, thin
fibers
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Nucleus
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How Are They Related?
 Chromatin-
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loose-made of
DNA, RNA, and
proteins
Chromosomes
-compact, tightwhen cell is
going to divide
Chromosome

Coiled up
chromatin
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Nucleolus
LOCATION:
 small dark area inside the
nucleus
 FUNCTION:
 makes ribosomes
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Go Bucks! We Beat Michigan!
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Plasma Membrane
LOCATION: Surrounds the cell
 FUNCTION: Sets off the cell
from its environment
 Controls what
goes in/out of
the cell
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PLASMA MEMBRANE
Double Membrane
Material Exits the Membrane Protein Channel
Animation
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Pili
Short projections of membrane
 Help hold onto surfaces
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Flagella
Longer
Projections
 Propel
through
water
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Flagellum
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9 + 2 arrangement
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* a cylindrical array of
9 filaments
* a pair of single
microtubules running
up through the center
of the bundle
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Cilia
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Shorter
Projections
Usually many of
them
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How do they move?

Flagella and Cilia Animation (Click)
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Cell Wall
Protects cell
 helps it maintain
its shape
 Outside the
cell membrane

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CELL WALL: only in plant
cells + prokaryotes
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Capsule
Sticky outer coat
 Helps glue it to surfaces (like
sticks, rocks, human tissue)
 Only in prokaryotes (bacteria)
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Capsule
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Cytoplasm
Fluid filled
region
between the
plasma
membrane
and nucleus
 (jello)
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Organelles
“little organs”
 most are membranous
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What goes on in them?
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Cellular
metabolism
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Chemical
activities of
the cell
What advantage is having
organelles?
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Separate the
chemicals of
cellular
metabolism
(some may be
toxic)
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Increases the
membrane
surface area
 (this is where
most
processes
occur)
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Ribosomes
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Small (21-25
nm)
assemble
amino acids
into
polypeptides
(protein)
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RIBOSOMES
 Assembles
the proteins
 Has two
subunits
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Ribosome
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Endomembrane System

(Organelles that are formed by
membranes)
– endoplasmic reticulum
– Golgi apparatus
– lysosomes
– vacuoles
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ENDOPLASMIC RETICULUM

Channels
within the
cell
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ER
 SMOOTH
ER = Has no
ribosomes
embedded in
it
 Makes lipids
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ENDOPLASMIC RETICULUM
Channels to
bring
materials to
ribosomes
 Assemble
proteins

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 ROUGH
ER
= has
ribosomes
embedded in it
Rough ER
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Path of Proteins
ER collects proteins
 creates a bubble around it
(transport vesicle)
 then to cell membrane or the
Golgi apparatus
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GOLGI COMPLEX
(Golgi apparatus, Golgi
Bodies)
 Sacs are not
 Looks like
interconnected flattened
stacks of
pita bread
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Golgi Apparatus

“Molecular
 Repackage
warehouse
and finishing proteins
factory”
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Golgi apparatus
Also known as
Golgi body
Golgi complex
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Making A Golgi Vesicle
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Vesicle Animations (Click)
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Vesicle Budding and Fusing
vesicle animation Push the finger to the
vesicle
Rediscovering Biology - Unit 10
Neurobiology: Animations and Images
(click on synaptic vesicles)
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Golgi Bodies
Making vesicles to carry out
repackaged proteins
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LYSOSOME
Vesicles that package the
enzymes that break up large
molecules.
 “clean-up crew”
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Breakin’ it Down
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WHAT? Food + damaged
organelles + bacteria
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LYSOSOMES
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Lysosome Animations
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HOW DO THEY FORM?
WHAT IS THEIR JOB?
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Peroxisomes
Form in an
oxygen –rich
environment
 (adds H to O to
make H2O2,
hydrogen
peroxide)
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VACUOLES: Food or Water
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contain water
and/or storage
materials
Food Vacuole (b) in Amoeba
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Food Vacuole Movies
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Phagocytosis (click)
phagocytosis movie (click)
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VACUOLES
Vacuoles are usually larger
than vesicles + lysosomes
 Largest structure in a plant
cell
 Smaller in animal cells
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Central Vacuole in Plants
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Full and Not Full Vacuoles
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Contractile Vacuole
Collect water and expel it to the
outside
 (click)Click on Contractile
Vacuole of Paramecium
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CHLOROPLASTS
 Only
in
plants
 green
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CHLOROPLASTS
Convert light energy
to chemical energy
(sugars)
 WHERE
PHOTOSYNTHESIS
TAKES PLACE
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Chloroplast
Granum =
stack of disks
where
chloroplasts
store energy
 stroma=area
between
grana
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MITOCHONDRIA

“cellular
respiration”
here
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Note the inner
folded area to
increase
surface area
“powerhouse”
(break down
fuel for energy)
MITOCHONDRIA
“cell’s powerhouse”
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Mitochondria

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Combines
food with
oxygen to
release
energy (such
as ATP)
Mitochondrion (note folds)
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Cytoskeleton
Support
 frame work
for the
 cell
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Cytoskeleton
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Cytoskeleton
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Microtubules
20
to 25 nanometers
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Microfilament
to 6 nanometers
Found in both
Plants and
animals
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3
Microtubule
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Actin stretching fibers
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In muscles
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Conveyor Belts in the cell
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Actin (red)
Microtubules (green)
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Cytoskeleton: Centrioles
 Only
in animal cells
 Used in cell division (act as
poles)
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Centrioles
Found
perpendicular in
pairs
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Microfilaments + Tubules
“cytoskeleton”
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Name the Organelles
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Interactive Cells
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Cell Models: An Interactive Animation
(click)
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A Typical Animal Cell - Learning Activity
- Fla - Flash Player Installation (click)
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Cell Junctions
Structures that hold the cells
together:
 Plant cells = plasmodesma
 Animal cells = extracellular
matrix
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“holes in the wall”
 Plasmodesma
 (plural)
=
Holes that
allow water to
pass through
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Note the channels between
cells
Plasmodesmata (sing.)
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Extracellular Matrix
Some
anchor,
communicate
with other
cells, or offer
leakproof
covering
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Name
the
parts
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