PowerPoint Learning QuestPowerPoint Learning Quest

Biology 9

Unit 6: Chemical Energy and Cellular Respiration

Created by: Jeff Wolf and Mike Graff

Objectives: After completing this Objectives: After completing this Learning Quest the student will…Learning Quest the student will…

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.

DirectionsDirections

1. Follow the instructions in the Anticipation Guide found in this PowerPoint Presentation.

2. Follow the instructions and answer all questions found in the Learning Guide.

3. Follow the instructions in the Conclusion Guide.

4. ALL THREE GUIDES CAN BE FOUND IN THIS LEARNING POWERPOINT QUEST.

Anticipation Guide (Page 1)Anticipation Guide (Page 1)

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.

Producers

Consumers

Anticipation Guide (Page 2)Anticipation Guide (Page 2)

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)Anticipation Guide (Page 3)

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)Learning Guide (Page 1)

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).

Kinetic Energy

Potential Energy

Learning Guide (Page 2)Learning Guide (Page 2)

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)Learning Guide (Page 3)

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)Learning Guide (Page 4)

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)Learning Guide (Page 5)

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)Learning Guide (Page 6)

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)Learning Guide (Page 7) 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)Learning Guide (Page 8)

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)Learning Guide (Page 9)

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)Learning Guide (Page 10) 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)Learning Guide (Page 11) 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)Learning Guide (Page 12)

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)Learning Guide (Page 13)

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)Learning Guide (Page 14)

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)Learning Guide (Page15) 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)Learning Guide (Page 16)

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)Learning Guide (Page 17)

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)Learning Guide (Page 18)

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)Learning Guide (Page 19) The oxygen transported to the cells is then used in

cellular respiration.

Learning Guide (Page 20)Learning Guide (Page 20)

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)Learning Guide (Page 21)

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)Learning Guide (Page 22)

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)Learning Guide (Page 23)

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)Learning Guide (Page 24)

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)Learning Guide (Page 25)

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)Learning Guide (Page 26)

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)Learning Guide (Page 27) 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).

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)Learning Guide (Page 28) 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)Learning Guide (Page 29)

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 respiration.

Learning Guide (Page 31)Learning Guide (Page 31)

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)Learning Guide (Page 32)

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 FermentationLactic Acid Fermentation

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 FermentationAlcoholic Fermentation

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)Conclusion Guide (Page 1) 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. 2. 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?

2. 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?

3. In cellular respiration, the steps following glycol sis depend on whether oxygen is present. Explain.4. Explain what is meant by carbon dioxide fixation. During which stage of photosynthesis does this

process take place?5. 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 this muscle fatigue.

Conclusion Guide (Page 2)Conclusion Guide (Page 2) Practice Assessment #2: Thinking Critically Part 1. Use the table below

to answer the following questions. Use page 98 of your text.

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.

Reaction ATP Produced (net) ATP Used/needed

Glycolysis 2 2

Krebs cycle 2

Electron transport chain 34 max.

Conclusion Guide (Page 3)Conclusion Guide (Page 3) 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)Conclusion Guide (Page 4) 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)Conclusion Guide (Page 5)

1. 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.

2. Was determining where there was more oxygen the purpose of his experiment? If not, state the purpose.

When the questions are completed, move onto the next slide

Conclusion Guide (Page 6)Conclusion Guide (Page 6)

3. How was the observation of the amount of oxygen present related to Engelmann’s purpose?

4. Why did Engelmann select aerobic rather than anaerobic bacteria?

5. Based on the diagram, what would Engelmann’s conclusion be?

When the questions are completed, move onto the next slide

Conclusion Guide (Page 7)Conclusion Guide (Page 7)

6. What was the independent variable in this experiment?

7. Describe one control Engelmann might have used. Explain.

8. Did Engelmann’s observations verify his hypothesis ? Explain

Works CitedWorks Cited

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.