Transcript Cellular Processes: What do cells do anyway?

Cellular
Processes:
What do cells
do anyway?
8.L.5-Understand the composition of various substances as it relates to
their ability to serve as a source of energy and building materials for
growth and repair of organisms.
8.L.5.1-Summarize how food provides the energy and the molecules
required for building materials, growth and survival of all organisms (to
include plants).
Essential Questions
 How
do cells produce food and energy?
 How do the different cell functions ensure
the survival of the entire organism?
The student will be able to…
 Explain
the function of different cell
organelles and how they work to produce
food and energy.
 Explain the different cellular functions
needed to sustain the life of the cell and
the life of the entire organism.
Important Vocabulary
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Photosynthesis
Chloroplasts
Respiration
Mitochondria
Selectively permeable
Active transport
Passive transport
Fermentation
Anaerobic respiration
Aerobic respiration
transpiration
Cell Organelle Review
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Cell membrane
Endoplasmic reticulum
Nucleus
Cytoplasm
Vacuole
Mitochondria
Golgi apparatus/bodies
Chloroplast
Cell wall
Moving Cellular Materials
 All
materials exchanged between a cell
and its environment takes place at the
cell membrane.
 Selective permeability: some substances
ability to move through the cell
membrane while other materials cannot
How cells make energy for
active transport
 Photosynthesis
 Cellular
respiration
Passive Transport
 Remember,
the cell membrane is
selectively permeable. This means it is
picky about what it let’s across! (How
many of you are picky eaters?)
 Some things move across the cell
membrane easily; so easy in fact that no
energy is required for it to cross! This is
passive transport.
Photosynthesis
 In
plant cells, photosynthesis happens,
where a plant cell captures energy from
the sun and uses it to make food.
 The chloroplast (found in the cells of
leaves) absorb sunlight, CO2 enters the
leaves and H2O enters through the roots.
The CO2 and H2O react with the captured
sun energy to make glucose (sugar) and
oxygen. The glucose is used as food for
the plant.
Photosynthesis Chemical
Formula
 Light
energy + 6CO2 + 6H2O
C6H12O6 + 6O2
(sugar)
Draw Photosynthesis (in
journal)
Making Energy
 Cellular
respiration changes glucose into
energy inside the mitochondria.
 The energy created during respiration is
what powers the cell and its organelles.
 Cellular respiration takes place in both
plant and animal cells.
Making Energy
 During
respiration, the chemical reaction
creates water and carbon dioxide along
with the energy, ATP.
 What does the cell do with the water
created?
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Stores it in the vacuole
Eliminates it from the body as either sweat
or urine (animal cells only)
Cellular Respiration Chemical
Formula
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C6H12O6 + 6O2
6CO2 + 6H2O + energy
What do you notice about this chemical formula?
Yes, it’s the reverse of the photosynthesis chemical
formula!!!!
The two processes, photosynthesis and respiration,
need each other to continue.
Fermentation
 Why
do you sometimes get sore muscles
from physical exercise?
 It’s
simple. Even if you’re breathing hard,
your cells may not be receiving enough
oxygen. When that happens, the cells will
go through a process called fermentation
to get energy when there is not enough
oxygen for respiration.
Fermentation
 Fermentation
is the cellular process that
cells use to release some of the energy
stored in glucose molecules if they do not
have enough oxygen for respiration.
 Fermentation takes place in the
cytoplasm; the reaction releases energy
and produces wastes.
 The wastes are lactic acid (in animal cells)
or alcohol and CO2 (in plant cells).
Fermentation
 The
lactic acid produces sore muscles,
yogurt, and some cheeses.
 Another name for fermentation is
anaerobic respiration meaning it takes
place without oxygen to make energy.
 Another name for cellular respiration is
aerobic respiration meaning it uses
oxygen to make energy.
Active Transport
 Okay,
if passive transport does not require
energy, what do you think active
transport requires?
 Yes! Active transport requires energy to
move things across the membrane.
 Some molecules, like the sugar molecule,
require energy to move across the
membrane.
Active and Passive Transport
Analogy
 Think
about riding a bike. If you are at the
top of a hill and coast down it, is that like
active transport or passive transport?
 If
you are at the bottom of a hill and need
to pedal to the top of the hill, is that like
active transport or passive transport?
Transpiration
 First,
what is transpiration?
 Yes, it is the water vapor being released
from the leaves.
 Go back and look at your respiration
chemical formula. What are the products
(things made) in that chemical reaction?
 Yes, carbon dioxide and water are made.
 The plant can either store the water
(where?) or can release the water during
transpiration.
Types of Transport
 Passive
Active Transport
Transport
 Osmosis
Transpiration
 Diffusion
Diffusion
 Diffusion
is a passive movement of particles across
the cell membrane.
 Things move from high concentration (crowded,
like the hallways in-between classes) to low
concentration (less crowded like the classroom).
 Example: The smell of a pie baking in the oven
filling the air with its scent.
 Cells like to be in equilibrium or homeostasis. This
means the cell likes the same amount of the
material on the outside as on the inside.
Osmosis
 Osmosis
is the diffusion of water across the cell
membrane
 It is passive transport
 Examples: A plant wilting—the water needs to
diffuse into the cells when it is watered. You
getting wrinkly in water—there is more water
outside of your body (high concentration) than
inside your body (low concentration).
Mitosis
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Mitosis is cell reproduction.
Occurs in the nucleus of a cell
Allows the cell to make an exact copy of
itself
Produces two daughter cells from one
parent cell
The daughter cells are identical to one
another and the original parent cell
Is needed for growth, replacement, and
asexual reproduction.
Mitosis Drawings
 Use
textbook, p. 538-539, Figure 4
 Drawings must be accurate, colorful, and
labelled.
Summary
 Answer
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the EQ’s.
How do cells produce food and energy?
How do the different cell functions ensure
the survival of the entire organism?