Download Plant Cell

How long have there been
cells?
•Bacteria evolved about 3 billion
years ago.
• Can be just a simple membrane
filled with DNA.
What allowed us to see
cells?
 The Microscope
 Robert Hooke
Cells
 The basic unit of life.
 The building blocks of all living things
The Cell Theory
 All living things are made of cells.
 Cells come from other cells (Cell Division).
 Cells are the smallest working units of living
things.
Levels of Organization
Smallest is a cell
tissue
organ
Organ system
Largest is an organism
Prokaryotes
 A prokaryotic cell has
no “true nucleus” and
lack membrane
bound organelles.
Still make proteins and
have DNA
Eukaryotes
 Eukaryotes have a nucleus and also
have all of the membrane bound
organelles.
Plant Cell
Key Feature?
Tough, rigid
CELL WALL
Animal Cell
Cytoplasm
Cytoplasm
Cytoplasm
 The “juice” of the cell.
 The “right”
environment for the
chemical reactions of
the cell.
Lipid Bilayers
Cell
Membrane
Cell Membrane, a lipid
bilayer
 The barrier between the cell and the environment.
 Controls what gets in and out of a cell.
 Building different membranes is one way different cell
types are made.
Plant Cell
Cell Wall
Cell Wall
 Made of cellulose.
 Serves to give a firm
structure to plants
 Can’t poop? Eat
more fiber (cellulose)
Nuclear Membrane
 Membrane around
nucleus.
 Carefully controls
what gets in and out.
 Protects DNA!
Nucleus
Nucleus
Nucleus
 Membrane Bound*
 Contains DNA (the
genetic instructions
that make you…
you).
Nucleolus
(Be careful to spell
correctly)
 Ribosomes (RNA and
proteins) assembled
here
Endoplasmic Reticulum
(ER)
ER
Endoplasmic Reticulum,
the ER
 Membrane Bound*
 Smooth ER makes
lipids.
(For Membranes)
 Rough ER (ribosomes)
makes proteins.
 Sends proteins to
Golgi.
Golgi Body (Golgi Stack)
Golgi
Golgi Body
 Sorts proteins.
 Sent to:
 Secreted (released
from cell)
 Plasma Membrane
 Membrane bound
organelles.
Secretes INSULIN.
Pancreas?
Not working?
Diabetes.
Lysosome
Lysosome
Lysosomes and
peroxisomes
 Membrane Bound*
 Store or destroy
waste.
 Lysosomes are
acidic, like your
stomach.
Secretory Pathway
 Proteins are coded
for by DNAmade on
rough ER by
ribosomessent to
Golgi for sortinggo
to




Lysosome
Nucleus
Cell Membrane or
release out of cell.
Vacuole
Vacuole
Vacuole
 Large in plants.
 Stores water
Chloroplasts
Chloroplast
Chloroplasts
 Membrane Bound*
 Sunlight energy is
converted to sugar.
 Filled with
chlorophyll, making
plants GREEN!
Mitochondria
Mitochondria
Mitochondria
 Membrane Bound*
(double membrane)
 Sugar is BURNED,
making ATP
(Energy).
 PLANTS and
ANIMALS get their
ENERGY HERE!!
Centrioles
Centrioles
Centrioles
 During Cell Division
separate
chromosomes into
the daughter cells.
 Plants organize their
spindles, but lack
centrioles.
Cytoskeleton
Cytoskeleton
Cytoskeleton
 Supports the cell:
 Actin
 Microtubules
 Molecules are also
transported through
the cytosol along
these skeletal
“tracks” with tiny
motors.
Chromosomes
 DNA, instructions for
making proteins
 Proteins manage the
chemical reactions
that are YOU!
Plant or Animal Cell?
Ribosomes
 Make proteins
 In cytoplasm or
studding the surface
of the rough ER.
Plant Cells
Chloroplasts
Cell Wall
Larger Vacuole
Animal Cells
Centrioles
Composition of Cell
Membrane
Proteins
Carbohydrates
Phosphate heads
Lipid tails
Phospholipid Bilayer
Diffusion
Movement
of molecules from a
high concentration to a low
concentration
When
molecules spread out to
an even concentration
Concentration Gradient
 Concentration difference on two sides of
a barrier
High
Low
Equilibrium
 An even concentration on both sides of
the membrane
Examples
 Perfume
 Gas
 Dye in water
Ultimately the molecules want to create a
balance or EQUILIBRIUM
Try This
 In a diffusion situation:
Osmosis
 Movement of water from a high to a low
concentration, in an attempt to even out a
concentration gradient of solute particles.
Examples
 Water in a dam
 Waterfalls
Wants to create an EQUILIBRIUM
Solve:
100 %
Water
90% H2O
10 % Iodine
95 % H2O
5% Iodine
95% H2O
5 % Iodine
Plasmolysis
A special case involving osmosis and
plants
 When water is drawn out of the cell
causing the cell membrane to shrink.
Selectively Permeable
http://www.indiana.ed
u/~p
hys215/lecture/lec
notes/lecgraphics/
diffusion2.gif
Passive transport – takes NO
energy. (like flowing downhill)
 Only works from High to Low
concentrations!
 Channels – only let certain things
through
Active transport – Takes
energy! (like walking uphill)


proteins- Use energy (ATP) to move
substances
channels – May transport two
molecules one is being concentrated
while other is diffusing (flowing from
High to Low)
http://www.biologie.uni-hamburg.de/bonline/library/biology107/bi107vc/fa99/terry/images/ATPpum
A.gif
Endocytosis (UPTAKE)


A “bubble” of membrane pinches off
Moving large particles INTO the cell.
Exocytosis (secretion) –
think opposite of
endocytosis (like EXIT)
 A “bubble” of membrane fuses with the cell
membrane
 Large particles move OUT of the cell.
Inside
Outside
Phagocytosis - like
endocytosis but with very
large particles (bacteria)
Red Blood Cells
being “eaten” by
a disease
fighting White
Blood Cell

http://gak.med.kagawa-u.ac.jp/~daigin/eng_info/Hisology_&_Cell_Biology/PIC2.jpg
Tissues
 What makes skin and muscle cells
different?
 Skin and muscle cells make different
proteins, allowing different jobs to be
done!
What makes cells
different?
 Even though each cell has all your DNA,
different parts are “read” and used in
different cells.
 This is called gene “expression” or gene
use
Muscle Tissue (myocytes)
 Cell Job: Movement
 Cell parts: cytoskeleton, myosin, and
ATP (energy)
 Many cells fuse to form one long cell,
with many nuclei
 Actin, Myosin and other proteins burn
ATP to allow movement.
Myosin walks on Actin
“tracks”

http://www.sci.sdsu.edu/movies/actin.gif
Muscle Fibers shorten
Nervous Tissue (neurons)
 Cell Job: Relay messages through the
body
 Cell Parts needed:
 various channels to relay “electrical” signal
 Chemicals to send message cell to cell
(neurotransmitters like dopamine, GABA,
serotonin, acetylcholine)
http://en.wikipedia.org/wiki/Image:SynapseIllustration.png
Intestinal Tissue
(epithelial cells)
 Cell Job: to absorb nutrients
 Cell Parts:
 Channels to let nutrients into cell
 Channels to pump nutrients into blood
stream
Concentrating nutrients in
blood
Eyes (Retinal Tissue)
 Cell Job: to sense light
 Cell Parts: various proteins that react to
light and others to deliver the message to
the optic nerve
 Rod cells in eye sense black and white
 Cones sense colors