Download Biology I Cells

Biology I Cells
Why is it good that your house is made
out of many smaller rooms rather than
one big space?
What is a cell?
A cell is a small specialized compartment
It keeps what is inside separate from
the rest of the organism
Why must living things be
made of cells?
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To have enzyme/substrate concentrations
high enough so that rates of reactions are
reasonable to support life (Rates of
Reaction)
Rates of Diffusion
Rates of Transport
Reactions can occur without interference
(conflicting reactions can happen
simultaneously)
Local environments can allow different
reactions to happen
Why must living things be
made of cells - continued
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Specialization (different cells can do
different things)
Damage can be contained
Cell Theory
Cell Theory Continued
All Living
Things are
Made of Cells
All Cells
Come From
Other Cells
Prokaryotic vs. Eukaryotic
Cells
Cell Membrane Structure
Phospholipid Bilayer
Cell Membrane Structure
Membrane Proteins
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Protein Channels – Control what moves
in and out of membrane
– Passive Transport
– Active Transport
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Receptors – Receives messages so the cell
knows what to do
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Marker or Signal Proteins – Identifies the
cell so your immune system knows what
belongs to you vs. foreign cells
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Attachment Proteins – attach cells to
other cells and ECM
Ways Things Move Through the
Cell Membrane
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Diffusion – movement of molecules from
a high to low concentration due to random
motion of molecules
Osmosis – diffusion of water
Simple diffusion – thru phospholipid
bilayer – driven by kinetic energy of the
molecules or atoms themselves
Ways Things Move Through the
Cell Membrane
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Facilitated diffusion – using the help of
protein channels
– Cell uses no energy, substances move from high to
low concentration (still diffusion)
– Used when molecules are polar, charged, or too big
– Channels are still small – nothing bigger than a
monomer goes through protein channels
Ways Things Move Through the Cell
Membrane
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Active Transport
– Movement through protein channels from
low to high concentration
– Cell must use energy to pump things
through
Ocean Fish pump
salt out of their cells
Muscle cells pump
Na+ out so they can
reset to contract
again
How can big things like
cholesterol and fatty
acids get into cells since
protein channels can’t be
big?
You will figure it out using the
following materials:
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A grocery bag as the cell
Candy as the large particles being taken in
2 pieces of string and scissors
The Rules
The inside of the bag (cell) cannot be open to the external
environment at any time
 You can put your hands inside the bag to manipulate the cell
membrane
 You cannot turn the bag inside out
 You cannot put the particles through the hole
 Food particles must remain together during the whole process
including after they enter the cell
 You cannot tie the food particles together with the string
You must demonstrate the process to me and show me how you
did it to win!
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Ways Things Move Through the
Cell Membrane
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Endocytosis – engulfing large
particles with part of the cell
membrane and bringing them into the
cell in a vesicle
Exocytosis – (secretion) – wrapping
molecules in a membrane vesicle
inside the cell – having it fuse with the
cell membrane and dump the contents
outside the cell (with or against conc.
Gradient – big stuff like proteins
Onion Cells with and
without stain
Elodea Cells and Salt Water
cytoplasmic streaming in
elodea
adding salt to a red
onion cell
Pond Water
https://www.youtube.com/watch?feature=player_de
tailpage&v=cwgGJaNlGKM