Transcript Chapter 6

PowerPoint Learning Quest
Biology 9
Unit 6: Chemical Energy and Cellular Respiration
Created by: Jeff Wolf and Mike Graff
Objectives: After completing this
Learning Quest the student will…
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Recognize the differences
between producers and
consumers in dealing with
energy flow and chemical
cycles within the biosphere.
Demonstrate chemical cycling
between photosynthesis and
cellular respiration.
Recall the basic energy
concepts including:
conservation of energy, laws of
thermodynamics, and chemical
energy.
Explain the process of cellular
respiration.
Directions
1.
2.
3.
4.
Follow the instructions in
the Anticipation Guide
found in this PowerPoint
Presentation.
Follow the instructions
and answer all questions
found in the Learning
Guide.
Follow the instructions in
the Conclusion Guide.
ALL THREE GUIDES
CAN BE FOUND IN THIS
LEARNING
POWERPOINT QUEST.
Anticipation Guide (Page 1)
Producers
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Most of all living beings can
be classified into two groups:
producers and consumers.
Producers are those who
develop food for other
organisms. Living organisms
such as plants develop food
through a process of
photosynthesis.
Consumers are those who
obtain their food by eating
plants or eating animals who
have eaten plants.
Consumers
Anticipation Guide (Page 2)
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Photosynthesis is the
process in which light
is synthesize or
transformed into
energy.
Photosynthesis uses
light energy to power
a chemical process
that makes organic
molecules.
Anticipation Guide (Page 3)
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In the following slides, we will be looking
at some basic energy concepts, cellular
respiration, the aerobic harvest of food
energy, as well as, the process of
fermentation.
 Use page 83 – 100 of your textbook as an
additional resource.
Learning Guide (Page 1)
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Kinetic
Energy
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Potential
Energy
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To understand the concept of
energy in reference to all living
organism one must first
understand what energy is.
Energy is anything that can do
work. Energy can be divided
into two groups: potential
energy and kinetic energy.
Kinetic energy is energy in
motion (Example: A rock
rolling down a cliff has kinetic
energy).
Potential energy is energy that
is stored (Example: A rock that
stays motionless on top of a
cliff has potential energy).
Learning Guide (Page 2)
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When a rock rolls down a cliff , the rocks energy
has changed from potential to kinetic energy. But
what happens to a rock’s energy when it stops
rolling at the bottom of the hill? Does the rock
lose energy?
 The answer is no. The rock will always convert it
energy from kinetic to potential, and then from
potential to kinetic. Therefore according to the
principle known as conservation of energy energy
cannot be lost or destroyed.
Learning Guide (Page 3)
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If energy cannot be
destroyed, where has it gone
once the rock reaches the
bottom of the hill? The
energy has been converted to
heat.
 Most of this heat is produced
by friction between the rock
and the side of the cliff.
 All energy conversions
generate some heat that can
be useful. This process of
generate and capturing of
useful heat can often be very
difficult.
Learning Guide (Page 4)
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So how can molecules
derived from the food
we eat provide energy
for our working cells.
Food, gasoline, and
other “fuels” have a
form of potential energy
called chemical energy.
Chemical energy has the
potential to perform
work.
Learning Guide (Page 5)
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If you take a look
at the diagram to
the left we have
two example of
chemical energy
conversion can be
seen.
Learning Guide (Page 6)
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In the part (a) of the diagram,
chemical energy, the gasoline
mixed with oxygen, is heated
within a combustion engine
of a car. This energy is
transferred from potential
energy to kinetic energy (i.e.
the movement of the car) and
heat energy from the engine.
The final waste products
from this conversion process
is the exhaust fumes (carbon
dioxide, water and a
considerable amount of heat).
Learning Guide (Page 7)
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In Part (b) of the
diagram, instead of
gasoline, food (i.e.
carbohydrates and fats)
mix with oxygen. This
process is called cellular
respiration. Heat energy
is produced as well as
energy for cellular work
called ATP.
The final waste product
from the cellular
respiration process is
carbon dioxide and
water.
Learning Guide (Page 8)
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As seen in the previous two
slides, automobiles and living
cells use the same basic
process to make energy out of
organic fuels.
In both cases, chemical energy
is not always converted into
kinetic energy or ATP, but
much of it is lost as heat.
In fact, cars are only 25%
efficient and the human body is
only 42% efficient at
converting food into useable
energy. The rest is simply
converted to heat. Note: you
have a warm body – 98.6
degrees Fahrenheit.
Learning Guide (Page 9)
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When dealing with the human
body, chemical energy is often
measured in Calories.
 A calorie is the amount of energy
that is required to raise the
temperature of 1 gram of water 1
degree Celsius. Calories are such
tiny units of energy that in order to
measure the true fuel contents of
food we must “scale up” the
calories by counting 1000 calories
together.
 1000 calories equal 1 kilocalorie.
The calories mentioned in all food
items are actually kilocalories.
Nutrition Facts for Red
Dragon Salsa.
Learning Guide (Page 10)
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The diagrams below illustrate food calories in different foods (a)
as well as food calories a human body burns in various activities
(b) .
Learning Guide (Page 11)
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Living cells are very
different than an
automobile engine in that
the living cells do not
burn the food to acquire
the energy needed to
survive.
 The chemical energy
required for cells is
contained in a molecule
called ATP.
 ATP stands for adenosine
triphosphate. The
diagram to the right is an
illustration of the ATP
structure.
Learning Guide (Page 12)
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ATP structure is a
complex molecule that
includes an adenosine plus
three phosphates. The
three phosphates or
triphosphate section is the
vital part to the ATP
structure
As seen in the diagram,
the energy is stored
between the phosphate
bonds.
Learning Guide (Page 13)
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The ATP structure acts like a
loaded spring. When a
spring is released it is now in
a relaxed form and can be
used for another task.
 When energy is transferred,
the unstable triphosphate
group a single, lone
phosphate breaks away and
transfers to other molecules.
 When this single phosphate
molecule breaks away, ATP
becomes ADP or adenosine
diphosphate.
Learning Guide (Page 14)
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When a phosphate breaks away
from the ATP structure, the lone
phosphate does not wander
freely. This phosphate powers
the mechanical work, transport
work, and chemical work done
within living cells.
 As seen in the diagram to the
right, before ATP becomes
ADP, the lone phosphate will
supply energy to create
movement (a), transport solutes
(b), and assist in the chemical
production within the cell ( c ).
Learning Guide (Page15)
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ATP is continuously working and
assisting in the mechanical, transport
and chemical work within living cells.
ATP can always be restored/recycle by
allowing the lone phosphate, used for
work, back into its original structure.
This pattern is called an ATP cycle.
In the ATP cycle, cellular work spends
ATP which is recycled from ADP and
the lone phosphate using energy from
food.
Therefore the ATP cycle can be called
an energy coupling system because of
its ability to transfer energy from
processes that produces energy to the
processes that consumes energy.
Learning Guide (Page 16)
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The next concept
presented in this
learning quest is the
concept of cellular
respiration.
 Cellular respiration is
an aerobic process.
 An aerobic process is
defined as a process
that requires oxygen.
Learning Guide (Page 17)
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Cellular respiration is closely related to the
concept we know as breathing.
 The connection between cellular respiration
and breathing is that both processes require
the exchange of two gases: oxygen and
carbon dioxide.
Learning Guide (Page 18)
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When a human being
inhales, that person
breathes in oxygen
(external respiration).
This oxygen (O2) is
transported across the
lining of their lungs
and deposited into that
person’s bloodstream
(internal respiration).
Learning Guide (Page 19)
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The oxygen transported to the cells is then used in
cellular respiration.
Learning Guide (Page 20)
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When cellular respiration
is completed, carbon
dioxide (CO2) , a waste
product of cellular
respiration/food
metabolism, is transported
away from the cells.
Carbon dioxide passes
through your lungs, and
leaves the body when a
person exhales.
Learning Guide (Page 21)
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In order for cellular respiration to occur,
glucose must be used in order for oxygen to
be transformed into part of three products;
water, energy, and carbon dioxide. This
process is illustrated in the diagram below.
Learning Guide (Page 22)
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When hydrogen is pulled from
the mixture of sugar and
oxygen, during the cellular
respiration process, we find a
transfer of electrons has
occurred.
 During cellular respiration,
hydrogen and its bonding
electrons change partners.
The hydrogen molecules are
loss. The final product
created is carbon dioxide.
 This process is known as
oxidation.
Learning Guide (Page 23)
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During the cellular
respiration process,
glucose is oxidized and
loses electrons of
hydrogen.
Molecules of oxygen gain
these hydrogen electrons
and form a final product
called water.
This process is known as
reduction.
Learning Guide (Page 24)
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Cellular respiration is a perfect
example of metabolism. This
means that a series of chemical
reactions occur in order to
transform food and oxygen
into energy.
Within a single process of
cellular respiration, more than
12 reactions are involved.
The three main metabolic
stages that take place during
cellular respiration are
Glycolysis, The Krebs Cycle,
and Electron Transport. Each
of these steps will be examined
in the upcoming slides.
Learning Guide (Page 25)
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Stage 1: The Glycolysis Stage
occurs outside the cell’s
mitochondrion and within the
cytoplasm.
In the Glycolysis stage, glucose is
split into two molecules called
pyruvic acid.
By splitting the sugars, two ATP
are gained.
With the assistance of the electron
carrier NAD (derived from Niacin
a B vitamin), the Glycolysis stage
is able to make ATP when enzymes
transfer phosphate groups from
food molecules to ADP.The result
is two pyruvic acid molecules.
The Glycolysis Stage
Learning Guide (Page 26)
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Before the Krebs Cycle can occur Pyruvic acid, the fuel product
developed from the Glycolysis process, must be first converted
into a form the Krebs Cycle can utilize.
 In the diagram below each pyruvic acid is transformed into an
Acetic Acid molecule and Acetyl –CoA. Refer to page 94 – 95.
Learning Guide (Page 27)
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Stage 2: The Krebs Cycle, uses a
series of inputs and outputs in order to
develop ATP.
As seen in the diagram to the right,
Acetic Acid is placed into the Krebs
Cycle. The results of this input
includes the production of:
– Carbon Dioxide.
– ATP/Energy
– NADH2 (pickes up hydrogen and
electrons).
– FADH2 (pickes up hydrogen and
electrons).
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It is important to recognize that the
products of the Krebs Cycle are a
result of the final/complete
breakdown of your food.
The Krebs Cycle Stage
Learning Guide (Page 28)
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Stage 3: The Electron Transport.
“Dealing with hydrogen electrons.”
This final stage uses the electrons
gathered by NADH2 and FADH2 to
produce 90% of the cell’s energy
(34 ATP).
The hydrogen that is received is
converted into water by adding
oxygen. Without oxygen your cells
would not be able to rid themselves
of hydrogen and complete the
process of cellular respiration. *
Note: This is why human are
aerobic organisms.
Once the mitochondria has received
ATP the cell now has the necessary
nutrition to survive.
Electron Transport Stage
Learning Guide (Page 29)
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Although pervious slides
have concentrated on
sugar as a fuel that can be
broken down in the
cellular respiration
process other types of
food can be used by the
cellular respiration
process as well to create
ATP.
Fats and proteins can also
be transferred into fuel
(ATP) through the three
stage process of cellular
Learning Guide (Page 31)
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Although cells need oxygen to
stay alive, cells can work for
short periods without oxygen.
Muscle cells are a good
example of cells that can
produce ATP during situations
where oxygen is not available.
Without oxygen conditions is
known as anaerobic.
Producing ATP when anaerobic
conditions prevail is called
fermentation.
Fermentation can occur in two
forms: Lactic Acid
Fermentation and Alcoholic
Fermentation.
Learning Guide (Page 32)
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Although you must breathe to
stay alive, some of your cells
can actually work for short
periods of time without oxygen.
Your muscle cells are a good
example. They can produce
ATP under conditions that are
anaerobic, meaning without
oxygen. This process is also
referred to as fermentation.
Refer to page 99 – 100.
Lactic Acid Fermentation
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Muscle cells have only enough ATP to support
anaerobic activity for about 5 seconds.
Plus, anaerobic activity is only 2% efficient at
converting food into ATP.
This process causes and “oxygen debt” and as a
result muscle soreness.
Generally, you may have experienced this after
vigorous activity or exercising.
Bacteria can also use this pathway and are used in
the production of yogurt,cheese, sauerkraut, soy
sauce and pickles.
Alcoholic Fermentation
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Like human muscle cells, yeast, a
microscopic fungus, is capable of both
aerobic and anaerobic respiration.
 However, yeast fermentation by contrast
will produce ethyl alcohol and carbon
dioxide.
 This type of fermentation is important in the
beer, wine and bread-making industries.
Conclusion Guide (Page 1)
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Practice Assessment #1: Understanding the Main Ideas of Unit 6. Answer the
following questions on a separate sheet of paper.
1.
Synthesis of Catcher at home plate – throw down.
molecules, transmission of nerve impulses, movement of cilia, and
bioluminescence are various activities of organisms.
A. What requirement do these activities have in common?
B. Why is ATP important in each activity listed above?
Both the wine industry and the bread industry use the process of alcoholic
fermentation.
A. In what way is the use of alcoholic fermentation by these industries similar?
B. In what way does their use of alcoholic fermentation differ?
In cellular respiration, the steps following glycol sis depend on whether oxygen is
present. Explain.
Explain what is meant by carbon dioxide fixation. During which stage of
photosynthesis does this process take place?
If you ran as fast as you could, your muscles may begin to feel weak and have a
burning sensation. Explain what is occurring in your muscle cells that account for
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4.
5.
Conclusion Guide (Page 2)
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Practice Assessment #2: Thinking Critically Part 1. Use the table
below to answer the following questions. Use page 98 of your
text.
Reaction
ATP Produced (net)
ATP Used/needed
Glycolysis
2
2
Krebs cycle
2
Electron transport chain
34 max.
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What is the net production of ATP molecules by each of the three
reactions?
What is the total net gain of ATP molecules per glucose
molecule?
The combination of glycolysis and fermentation yields a net gain
of 2 ATP molecules. How many molecules of ATP does
fermentation yield by itself? Explain. Check page 98.
Conclusion Guide (Page 3)
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Practice Assessment #3: Thinking Critically Part 2. Read the
following paragraph and answer the questions below.
In an experiment conducted to determine whether green plants
take in carbon dioxide, a biologist filled a large beaker with
aquarium water to which she added bromothymol blue. She
exhaled carbon dioxide into the solution of bromothymol blue,
which made the solution turn yellow. Then she placed a
branch of Elodea (aquatic plant) into two test tubes. She left a
third test tube without Elodea to serve as a control. She added
the yellow bromothymol solution to all three test tubes and
placed a stopper in each. Next she placed all the test tubes in
sunlight. After several hours in sunlight, the bromothymol
solution in the test tubes with the Elodea turned blue. The
bromothymol solution in the control remained yellow.
1.
What conclusion can be drawn from the experiment? Explain.
Conclusion Guide (Page 4)
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Practice Assessment # 4: Applying Scientific Methods.
In 1803, Germany’s Thomas Engelmann used a combination of aerobic bacteria and
filamentous alga to study the effect of various colors of the visible light spectrum on
the rate of photosynthesis. During his experiment, Engelmann passed which light
through a prism in order to separate the light into the different colors of the
spectrum. Then Engelmann would expose different segments of the alga to the
various colors. By completing this process he was able to observe in which areas of
the spectrum the greatest number of bacteria appeared. Refer to the diagram below
to answer the questions on the next slides.
Conclusion Guide (Page 5)
When the
questions
are
completed,
move onto
the next
slide
1.
2.
Using this setup, Thomas Englmann was able to determine in which
areas of the visible light spectrum the alga was releasing the most
oxygen. Explain his reasoning.
Was determining where there was more oxygen the purpose of his
experiment? If not, state the purpose.
Conclusion Guide (Page 6)
When the
questions
are
completed,
move onto
the next
slide
3.
4.
5.
How was the observation of the amount of oxygen present related to
Engelmann’s purpose?
Why did Engelmann select aerobic rather than anaerobic bacteria?
Based on the diagram, what would Engelmann’s conclusion be?
Conclusion Guide (Page 7)
6.
7.
8.
What was the independent variable in this experiment?
Describe one control Engelmann might have used. Explain.
Did Engelmann’s observations verify his hypothesis ? Explain
Works Cited
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http://mil.citrus.cc.ca.us/cat2courses/bio104/ChapterNotes/images/ch43/0853l.jpg
http://big8rcd.org/Mvc-598f.jpg
http://www.scd.ucar.edu/news/01/fotoweek/0702.deer2.jpg
http://www.supercable.es/~artisfa/images/030201035c.gif
http://nobel.scas.bcit.ca/chem0010/unit2/images/cliff.jpg
http://nobel.scas.bcit.ca/chem0010/unit2/images/cliff_ke.jpg
http://www.totalmotorcycle.com/downloads/pics/gasoline.jpg
http://www.fst.uq.edu.au/staff/bdarcy/food2002/food201.jpg
http://www.redgatorsalsa.com/med.gif
http://wings.avkids.com/Book/Sports/Images/cyclist.gif
After completing the test, move onto Unit #7.