Download Thursday, Jan. 22, 2009 Opening Question:

Thursday
Agenda:
Opening Question:
Prokaryote/Eukaryote
foldable
•Community Cells
What are at least five things
that you know about cells?
•
Cells-R-Us
• Cell Theory- The cell theory
consists of three components listed
below:
• 1.) all organisms are made up of
one or more cells,
• 2.) cells are the basic units of
structure and function in all
organisms, and
• 3.) all cells come from cells that
already exist.
Eukaryotes and
• Nucleus (plantsProkaryotes
and
• No nucleus (bacteria)
animals)
Prokaryote versus Eukaryote
Prokaryote
Eukaryote
Plant
Versus
Animal
Plant Cells
Animal Cells
Cell Membrane
• Nickname: “the
fence”
• Function: boundary
separating the cell
from surrounding
cells and invaders
• Controls what enters
and exits the cell
Cytoplasm
• Nickname: “the air”
• Function: jelly-like
material inside the
cell membrane.
Surrounds the nucleus
and organelles.
Ribosomes
• Function: makes proteins
• Found in all cells, prokaryotic and eukaryotic
• Nickname: “Roads”
• Function: The internal delivery system of the cell
Endoplasmic Reticulum
(ER)
Golgi Apparatus
• Nickname: The
shippers
• Function: packages,
modifies, and
transports materials to
different location
inside/outside of the
cell
• Appearance: stack of
pancakes
Lysosomes
Lysosomes: circular, but bigger than ribosomes)
•
•
Nickname: “Clean-up Crews”
Function: to break down food into particles the rest of the
cell can use and to destroy old cells
Mitochondria
• Nickname: “The Powerhouse”
• Function: Energy formation
• Breaks down food to make energy
Vacuoles
Vacuoles
Nickname: The warehouse
•
•
Function: stores water
This is what makes lettuce crisp
•
When there is no water, the plant wilts
In Plants Only:
• Cell Wall
• Located on the outside of
the cell membrane.
• Acts as an extra fence.
• Supports and protects the
plant cell.
• Chloroplasts
• Organelles that capture
energy from sunlight.
• Aids in photosynthesis.
Exit Slip
• 3-2-1
• 3 things you learned
• 2 ways you contributed
• 1 question you still have
• On flip side, tell me:
• the difference between a
prokaryote and a eukaryote
Agenda
•
•
•
•
Review
Cells project
Project presentation
Exit slip
Nucleus
• Nickname: The Brain
• Function: Contains the DNA and controls all functions
within the cell.
CELLS!!!!
Construct a model of an plant cell by adding
one organelle (cell part) at a time using
construction paper. Create an organelle from
the sheet given, color and add it to your
drawing.
 I will pass out to each group an organelle
sheet. Clearly label & Recreate that organelle
and cut it out and put it in your cell.
 Be prepared to present an organelle to the
class.

CELLS!!!!
• The last organelle you receive will be the one
you present.
• One person from each group must present.
• The best Cell project picked and the best
presenter will each get a 5 point bonus
towards their cell book project.
Exit Slip
• 1 question you still have
• Below that:
• Two differences between a
Ribosome and a Mitochondria
Wednesday
Agenda:
Opening Question:
Lab
•Review
•Quiz
What do you know about a
microscope?
•
Thursday
Agenda:
Opening Question:
Plant and animal cell
foldable
•Review
•Osmosis
What do you know about
Osmosis?
•
Review
• Organelles
• Name
• Nickname
• Function
Foldable
Plant Cells
Animal Cells
Diffusion
• Diffusion- the movement of molecules from an area
where there are many to an area where there are few
• Movement of molecules from an area of high
concentration to an area of low concentration.
Functions of Membranes
1. Protect cell
2. Control incoming and outgoing substances
3. Selectively permeable - allows some molecules in, others are
kept out
Phospholipid Bilayer
• Allows some substances into the
brain, but screens out toxins and
bacteria
• Substances allowed to cross include:
water, CO2, Glucose, O2, Amino Acids,
Alcohol, and antihistamines. HIV and
bacterial meningitis can cross the
barrier.
Blood-Brain Barrier
1. Diffusion -passive transport - no energy
expended
2. Osmosis - Passive transport of water
across membrane
3. Facilitated Diffusion - Use of proteins to
carry polar molecules or ions across
4. Active Transport - requires energy to
transport molecules against a concentration
gradient – energy is in the form of ATP
Methods of Transport
Across Membranes
Diffusion
Osmosis
Facilitated Diffusion
Active Transport
Osmosis
• Osmosis- the diffusion of water through a cell membrane
1
2
Osmosis is a special case of diffusion
Osmosis involves the diffusion of water
through a membrane
The membrane may be artificial and
non-living e.g. Cellophane
In biology, the important membrane is the
cell membrane
3
Permeability
The membrane must allow water molecules
to diffuse through. It is permeable to water.
If a concentrated solution is separated from
a dilute solution by a suitable membrane,
water will pass from the dilute to the
concentrated solution.
In fact, water passes both ways but faster
from the dilute to the concentrated solution.
is
4
water or
dilute solution
concentrated
solution
level falls
level rises
membrane
More water passes from
dilute to concentrated ...
...until concentrations
become equal
5
There are microscopic pores in the membrane.
Molecules below a certain size can diffuse
through the pores.
Water molecules can easily diffuse through
the pores.
In the next slides
and
represents a water molecule
represents a sugar molecule
water
membrane
6
sugar solution
There are as many water molecules on the right as
there are on the left but many of them are attached to
sugar molecules and are not free to move.
9
Because the membrane allows only molecules
of a certain size to diffuse through it, it is
called selectively permeable.
The cell membrane functions as a selectively
permeable membrane.
Osmosis in animal cells
There is a greater concentration
of free water molecules outside
the cell than inside
11
so water diffuses into the cell
by osmosis
and the cell swells up
12
If osmosis continued the animal cell would
burst
This would be bad news for animals
Consequently there are processes in the
animal’s body which control osmosis
Mainly, this is done by keeping the
concentration of body fluids outside the cell
the same as it is inside. This is called
Fresh water fish
14
Trout
In fresh water fish, the blood is more
concentrated than the surrounding water
As a result the fish takes in water by osmosis
Not so much through the skin, which is thick,
but through the gills which have a very thin
membrane
14
Perch
The fish gets rid of the excess water by means of its kidneys
kidneys expel
excess water ...
blood carries water
to kidneys
gills absorb water
by osmosis
heart
...in the form of
dilute urine
Sea water fish
15
Herring
Sea water is a more concentrated solution than the
fish’s blood. What will be the osmotic effect ?
A sea water fish will lose water by osmosis through
its gills.
The fish drinks sea water and the gills expel the
excess salt from the blood, so keeping its
concentration constant
16
In a plant cell, the cell membrane acts as a
selectively permeable membrane
The cell wall is freely permeable to water
If there is water outside the cell, it will diffuse
by osmosis into the vacuole
The cellulose cell wall cannot stretch, so the
vacuole cannot continue to expand
But the pressure of the vacuole against the cell
wall makes the cell very firm and the plant
stands upright
17
Plant cells
cell wall
18
vacuole
The cell absorbs water
by osmosis ....
cytoplasm and
cell membrane
....but the cell wall stops the
cell expanding any more
Limp and turgid tissue
These cells are short of
water; the tissue is limp and
the plant is wilting
21
The cells have taken up
water by osmosis; the
cells are turgid and the
tissue is firm
• 1. Materials are moved into and out of the cell through which
organelle?
•
•
•
•
a. cell membrane
b. mitochondria
c. ribosomes
d. nucleus
• 2. What process allows water to move into and out of the cell?
•
•
•
•
a. Diffusion
b. Meiosis
c. Osmosis
d. Pinocytosis
Exit Slip
Wednesday, March 3, 2010
Agenda:
•
Mitosis Notes
Opening Question:
Mitosis is the process in which the
nucleus divides to form two
new nuclei. How might mitosis
differ in plants and animals?
Also, please put the “mitosis”
definition in your binder
glossary.
56
56
How do little elephants grow up to be BIG
elephants?
The process of sexual
reproduction begins after a
sperm fertilizes an egg.
Skin cancer - the abnormal growth of
skin cells - most often develops on skin
exposed to the sun.
Cell that reproduce by asexual
reproduction reproduce constantly.
Animated Mitosis Cycle
http://www.cellsalive.com/mitosis.htm
• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase & Cytokinesis
•
•
Chromosomes are copied (# doubles)
Chromosomes appear as threadlike coils
(chromatin) at the start, but each chromosome
and its copy(sister chromosome) change to
sister chromatids at end of this phase
Nucleus
CELL
MEMBRANE
Cytoplasm
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
•
•
•
Mitosis begins (cell begins to divide)
Centrioles (or poles) appear and begin to
move to opposite end of the cell.
Spindle fibers form between the poles.
Centrioles
Sister chromatids
Spindle fibers
Animal Cell
Plant Cell
Spindle fibers
Centrioles
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
•
Chromatids (or pairs of chromosomes) attach
to the spindle fibers.
Centrioles
Spindle fibers
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
•
Chromatids (or pairs of chromosomes)
separate and begin to move to opposite ends
of the cell.
Centrioles
Spindle fibers
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
•
•
•
Two new nuclei form.
Chromosomes appear as chromatin (threads
rather than rods).
Mitosis ends.
Nuclei
Chromatin
Nuclei
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
•
Cell membrane moves inward to create two
daughter cells – each with its own nucleus
with identical chromosomes.
Animal Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
Plant Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
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- Cell Division
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http://www.cellsalive.com/mitosis.htm