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01/09/15- No gum Please!
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Materials
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Pen/Pencil
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Notebook
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Packet
Book pg 48
Objective: Today
we will describe
how materials
move into and out
of the cell through
the cell membrane
Agenda
Daily question
Chapter 2
Packet
Notes
Daily Question:
what is
photosynthesis?
Plant Vs. Animal Cell Lab
 Obtain materials from teacher
 Set magnification to 10x first (low power)
 Put Elodea slide under microscope observe what it looks
like on low power –draw a picture
 Put Elodea slide on high power, observe and identify
organelles-draw scientific picture in notebook
 Have one student come up to Ms. Mildebrath and swab
cheek cell, Ms. Mildebrath will put dye on slide, return with
animal cell to group
 Put animal cell under low power microscope, observe
organelles and structures- draw scientific drawing in
notebook
 Put animal cell under high power and observe changes,
identify organelles and draw observations in notebook
Scientific Drawing Example
Cork cell
Cell
membrane
Cork cell
100x
Photosynthesis
 Is the process that plant
cells use to change the
energy from sunlight into
chemical energy. Takes
place in the chloroplasts.
 Chlorophyll- a light
absorbing pigment, or
colored substance, that
traps the energy in sunlight.
 Chemical equation-
𝐻₂0 + 𝐶𝑂₂
⟶ 𝐶₆𝐻₁₂𝑂₆ + 𝑂₂
Cellular Respiration
Cells use oxygen to
release energy stored in
sugars such as glucose.
Takes place in
organelles called
mitochondria.
Chemical equation-
𝐶₆𝐻₁₂𝑂₆ + 𝑂₂ ⟶ 𝐻₂0 +
𝐶𝑂₂
Materials move across the cell’s
membranes
Diffusion
Osmosis
Active Transport Vs. Passive
Transport
Endocytosis (in)
Exocytosis (out)
Diffusion
Diffusion is the process by which
molecules spread out or move from areas
where there are many of them to areas
where there are fewer of them.
Diffusion helps cells maintain conditions
that are necessary for life. During cellular
respiration oxygen enters your cells by
the process of diffusion. Also, carbon
dioxide leaves cells by diffusion
Concentration and Diffusion
The concentration of a
substance is the number of
particles of that substance in
a specific volume.
The greater the difference in
concentration between two
areas, the more rapidly
diffusion occurs.
Ex. When you add salt to water, although you may
be able to see salt sitting at the bottom of the cup,
you are able to taste the salt mixed in with the
water. This is because the concentration of salt has
become the same throughout the cup.
Osmosis
Osmosis -is the
diffusion of water
through a membrane.
This is how water moves into and out of the cells in
our bodies.
If the concentration of water is higher outside of the
cell, then the water moves into the cell until it has
reached equilibrium.
Ex: Watering plants – if you forget to water a plant, it
wilts. The soil dries out, and the plant’s roots have
no water to absorb. Water leaves the plant cells by
osmosis and they shrink. If you water the plant, the
leaves return to normal as water moves back into
the cells.
Active Transport and Passive Transport
Active transport is the process of using energy to
move materials through a membrane. Endocytosis
and exocytosis are examples of this.
Ex. Our kidneys filter wastes from our blood by active
transport. The cells in the kidneys remove the
excess salt from the blood.
Passive transport is the
process of moving
materials without using
the cell’s energy.
Diffusion and osmosis
are examples of this.
Ex. Glucose is able to
move into out of cells to
give it the food energy it
needs.
Endocytosis and Exocytosis
Endocytosis is the process in
which a portion of the cell
membrane folds and
absorbs a particle in order
to move it into a cell.
Cells in the body use this
process to fight bacteria
and viruses.
Exocytosis is the process in
which a membrane within
a cell encloses the
material that needs to be
removed. This membrane
then joins with the cell
membrane. Cells use
exocytosis to get rid of
waste materials, proteins,
or hormones.