Transcript Stem Cells!

Cell Structure
and Function
Chapter 3
Size Comparison
Domain II:
Cellular Basis of Life
*Explain the cellular basis of life
*Homeostasis
*Transport cellular material through cell
membrane
*Stem Cells
What is a Stem Cell?
• What have you heard about stem cells?
• Where do you think stem cells come
from?
Cute
Stem
• What are stem cells for?
Cell
• What is a cell?
Animation
• What do you think is the benefit of
stem cells?
Name the 3 parts of the Cell
Theory?
• 1) Cell is the basic unit of life
• 2) All organisms are composed of
cells
• 3) All cells come from pre-existing
cells
Who were the initial cell
Scientists? Pg.71
• Robert Hooke 1665. First to see a
cell. Named it after Monk Cells.
(Cork)
• Anton van Leeuwenhoek 1673.
1st to see microscopic organisms.
What characteristics are needed to
consider something alive?
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1) Require food for energy
2) Use energy to maintain homeostasis
3) Respond to stimuli
4) Grow and develop
5) Reproduce similar offspring
6) Ability to pass genetic information
7) Made of cells
What is the difference between a
multicellular and unicellular organism?
• Unicellular – exist as a single
independent cell. Example: amoeba
• Multicellular- organisms that exist as
specialized groups of cells.
• Order of cellular specialization: cells,
tissues, organs, organ systems,
organism
Which of the following is a correct
statement regarding tissues?
• A) Tissues hold organs together
• B) Tissues form plasma membranes
• C) Tissues are composed of organs
with several functions
• D) Tissues are composed of cells with
similar functions
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Answer: D
What is the difference between a
prokaryote and a eukaryote?
• Prokaryote-No membrane bound
organelles. Only bacteria are
Cell
considered prokaryotes. pg.72 Comparisons
• Eukaryote- Contains membrane
bound organelles, including a true
nucleus.
Which of the following is an
example of a prokaryotic cell?
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A)An animal cell
B) A bacterial cell
C) A fungal cell
D) A plant cell
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Answer : b, both archae and Eubacteria are prokaryotes
What do all cells have in
common?
Fluid-Mosaic
Model
• Have a plasma membrane- semipermeable structure surrounding
the cell
• Cytoplasm- jelly-like substance
where cells chemical reactions
occur as well as where organelles
are found.
How are cells different?
Stem
Cell
Differentiation
• Size: Cells must be small for diffusion.
The closer the surface Area/Volume
ration the more diffusion. Shape: Fig 42. Long, Flat, Branching, etc.
• Type of organelles and the number of
each kind. (Red blood cells have no
nucleus, Animal cells have no cell wall.)
• Different types of cells have different
needs therefore different structures.
What is a stem cell?
What is an Organelle?
• Part of a cell that performs a job.
Like an organ does a job for the
body organelles do the same for a
cell.
United streaming
video clip
Cell Movie: Amoebas &
Animal Cells
Which organelles are found in
plant cells but not in animal
cells?
• Plastids such as Chloroplast- capture
solar energy for photosynthesis
• Cell Wall- Adds structure and support
to the cell
• Plants also have much larger vacuoles
for storing water then animal cells. Classzone
Animal Vs.
Plant
Define the following organelles:
Golgi bodies, Mitochondria, Nucleus,
Ribosome, and Vacuoles.
• Golgi bodies- package and
distribute lipids and proteins
• Mitochondria- powerhouse of
the cell, transforms energy
Definitions continued…
• Nucleus- contains DNA which
controls cellular activities
• Ribosomes- produce proteins,
found on the rough ER
• Vacuoles- store substances such as
water.
Define the following organelles:
Smooth Endoplasmic Reticulum (ER), Rough ER,
• Smooth Endoplasmic Reticulum
(ER): Make Fats such as steroids.
• Rough ER: Contain Ribosomes.
Package and ship proteins made on
Ribosomes.
Organelles Continued
• Lysosome: Contain Digestive
Great
enzymes. Think SOS…
Lysosome
Short Movie
• Nucleolus: Ribosomes and other
RNA are synthesized.
Define the following organelles
• Flagella: Whip like structure made of
microtubules. Few in number and
long.
• Cilia: numerous short hair-like
structures. Also made of Microtublules.
Flagella and Cillia
Video Clip
Very Good!
In the animal cell, in which cell part
does cellular respiration occur?
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A)
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Answer: A Mitochondria
Organelle
Review
Link
Organelle
Self-Quiz
Review: Which of the following
is a characteristic of all living
things?
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A) Cellular Structure
B) Nervous System
C) Chlorophyll
D) Hemoglobin
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Answer: A
Review: What is homeostasis?
• Maintenance of internal
equilibrium
• Example: Body to returning to
normal temperature (98.7) after a
fever.
Which of the following statements
best demonstrates homeostasis?
• A) The intestine has a large surface
area.
• B) Humans tend to have 5 fingers on
each hand.
• C) Humans sweat when they get hot
• D) Cells have maximum attainable
size.
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Answer:C
Back to Stem Cells!
• How are stem cell made?
• Why do you think stem cells exist?
• Do differentiated cells have
different organells?
Making
Stem
Cells
Ch 3.4 & 3.5: Homeostasis and
Transport
• How do substance enter and exit a cell?
• What is the difference between active and
passive transport?
• How does the chemical make-up of the
plasma membrane affect what can enter and
exit the cell?
Membrane
Transport
The plasma membrane only
allows certain things to enter
and exit the cell. What is this
called?
• Selectively permeable membrane or
selectively permeable
What is passive transport? Name
and describe the 3 types.
• Passive Transport- movement of
substance of substances across the
plasma membrane without the use of
energy.
Passive
Transport
The Three Types
Diffusion: movement of substances
across the plasma membrane from
high to low concentration
Osmosis: diffusion of water across
the plasma membrane from high to
low concentration
Facilitated Diffusion: carrier
molecules transport larger
substances across the membrane
from high to low.
What is active transport?
Describe the two major types.
• Active Transport: uses energy and
carrier molecules to move substances
across the plasma membrane from low
to high concentrations (against the
concentration gradient)
Active
Transport
The two types of Active Transport
• Endocytosis: process by which
large particles are brought into
the cell
• Exocytosis: process by which
large particles leave the cell
Endo/
Exocytosis
Substances that are too large to be moved
across the plasma membrane can be
engulfed through the process of …
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A) Diffusion
B) Endocytosis
C) Exocytosis
D) Osmosis
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Answer: B
• Endo= inside, Exo= Outside, cyto=cell,
osis= process or action
There are 3 types of solutions a
cell can be in.
• 1) Hypotonic
• 2) Hypertonic
• 3) Isotonic
Red blood cell
Hypo/Hyper/
Iso Solutions
Hypo/Hyper/
Iso
Scroll Down
Describe a cell in an isotonic
solution.
• Iso= the same. The concentration of the
solution is the same inside and outside the
cell.
• The cell stays the same size.
• There is no net movement across the plasma
membrane (things enter and leave the cell at
the same rate)
Describe a cell in an hypertonic
solution.
• Hyper= above. The concentration of the
solution is higher outside the cell than
inside.
• The cell shrivels in size.
• Water leaves the cell at a faster rate then it
enters.
Describe a cell in an hypotonic
solution.
• Hypo= below. The concentration of
solutions is lower outside the cell then
inside.
• The cell swells or pops in size. hyPO=POP
• Water enters the cell at a faster rate than it
leaves
A student is making a model to demonstrate
how cells respond to solutions with varying
concentrations of salt and water. She soaked a
kidney bean in distilled water until it started to
swell. In what kind of solution should she put
the swollen bean to cause it to shrivel?
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A) Acidic
B) Basic
C) Hypertonic
D) Hypotonic
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Answer: C