Section 8.1 Energy and Life Name:

Biology Date: Period:

Lesson Objectives Describe the role of ATP in cellular activities. Explain where plants get the energy they need to produce food.

Lesson SummaryChemical Energy and ATP Energy is the ability to do work. Organisms need energy to stay alive.

Adenosine triphosphate (ATP) is a chemical compound cells use to store and release energy.o An ATP molecule consists of adenine, the sugar ribose, and three phosphate groups.o Cells store energy by adding a phosphate group to adenosine diphosphate (ADP) molecules.o Cells release energy from ATP molecules by removing a phosphate group.

Energy provided by ATP is used in active transport, to contract muscles, to make proteins, and in many other ways.

Cells contain only a small amount of ATP at any one time. They regenerate it from ADP as they need it, using energy stored in food.

Heterotrophs and Autotrophs The energy to make ATP from ADP comes from food. Organisms get food in one of two ways.

Heterotrophs get food by consuming (eating) other organisms. Autotrophs use the energy in sunlight to make their own food. Photosynthesis is the process that uses light energy to produce food molecules.

Chemical Energy and ATPFor Questions 1–6, complete each statement by writing the correct word or words.

1. is the ability to do work.

2. The main chemical compound cells use for energy is (ATP).

3. is a 5-carbon sugar molecule that is part of an ATP molecule.

4. The of ATP are the key to its ability to store and supply energy.

5. ATP releases energy when it bonds between its phosphate groups.

6. Most cells only store enough ATP for of activity.

7. Label each part of the diagram of an ATP molecule below.

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8. In the visual analogy, what chemical is represented by the low battery?

9. What are two ways in which the diagram shows an increase in energy?

10. Describe the concepts shown in the diagram.

11. What are two ways in which cells use the energy temporarily stored in ATP?

12. Energy is needed to add a third phosphate group to ADP to make ATP. What is a cell’s source of this energy?

Heterotrophs and Autotrophs - For Questions 13–17, write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true.

_________________1._________________2._________________3._________________4._________________5._________________6._________________7._________________8._________________9._________________10._________________11._________________12._________________13. All heterotrophs must eat food to get energy.

_________________14. Autotrophs do not need to eat food because they make food.

_________________15. The energy in food originally came from ATP.

_________________16. The term photosynthesis means “pulling apart with light” in Greek.

_________________17. The energy of sunlight is stored in the chemical bonds of carbohydrates.

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13.14.15.16.17.18. Complete the table comparing two types of organisms.

Autotrophs and HeterotrophsType Description Examples

Autotrophs

Heterotrophs

Why are Plants Green? Name:

Biology 6.0 Date: Period:

IntroductionA pigment is a molecule that absorbs light. The leaves of most plants are rich in pigments. These pigments absorb light and convert it into chemical energy to fuel the production of sugars. The primary photosynthetic pigment is chlorophyll a and chlorophyll b. Other pigments such as carotenoids and xanthophyll are referred to as accessory pigments. These accessory pigments absorb light in other regions of the spectrum making the plant more efficient in absorbing sunlight and photosynthesis.

Different types of pigments absorb different types (wavelengths) of light. Some pigments might absorb blue light better than other wavelengths of light for example. A spectrophotometer is a machine used by scientists to measure the absorbance of light by substances. The better a pigment absorbs a color (wavelength) of light, the higher percent of absorbance reading. The data in Table 1 gives a possible spectrophotometer absorbance reading for the two plant chlorophylls a and b. Graph the data for chlorophyll a and chlorophyll b on the same graph. The line for each is an approximation of the absorption spectrum for that molecule.

Table 1:Wavelength

nanometers (nm)Chlorophyll a % Absorption

Chlorophyll b % Absorption

Carotenoids% Absorption

400 32 8 22425 60 29 23450 10 62 49475 3 51 43500 0 8 55525 0 0 34550 4 3 0575 2 4 0600 4 2 0625 3 20 0650 21 29 0675 44 4 0

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700 12 0 0

Analysis1. Color code your graph in a way that clearly shows the color range between 400 and 700 nanometers.

400-425: Violet 450-475: Blue 500: Blue-Green 525-550: Green

575: Green-yellow 600: Yellow 625: Orange 650: Orange-red675-700: Red

2. Based on the data and your graphs, what can you conclude about the two chlorophylls and their absorption

spectra? In what ways are the two similar? Different?

3. Chlorophylls are the predominant pigments in leaves. Based on the data and your graph, give a possible

explanation for why plants are green.

4. If some wavelengths (colors) of light are absorbed by chlorophylls, what happens to the other wavelengths

that are not absorbed?

5. Based on your graph, which type of light is most important to plants for photosynthesis? Explain.

The yellow-orange carotenoids in leaves absorb wavelengths of light that chlorophyll a and chlorophyll b cannot. The energy collected by carotenoids through light absorption is channeled to chlorophyll a in photosynthesis. Use the data from Table 1 to make an absorption spectrum graph for carotenoids, as you have done previously for chlorophyll a and b. Put the data for the carotenoids on the same graph as the chlorophylls.

6. What color corresponds with the carotenoids? Explain using evidence from your graph.

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7. What is the adaptive value of accessory pigments like carotenoids? That is, what advantage do they provide

the plants?

8. Leaves of many North American trees change color in the fall or before a dry season. Explain why and

relate your answer to carotenoids.

Why Leaves Change ColorThe Splendor of Autumn - Every autumn we revel in the beauty of the fall colors. The mixture of red, purple, orange and yellow is the result of chemical processes that take place in the tree as the seasons change from summer to winter. During the spring and summer the leaves have served as factories where most of the foods necessary for the tree's growth are manufactured. This food-making process takes place in the leaf in numerous cells containing chlorophyll, which gives the leaf its green color. This extraordinary chemical absorbs from sunlight the energy that is used in transforming carbon dioxide and water to carbohydrates, such as sugars and starch. Along with the green pigment are yellow to orange pigments, carotenes and xanthophyll pigments which, for example, give the orange color to a carrot. Most of the year these colors are present but they are masked by great amounts of green coloring. Chlorophyll Breaks Down - But in the fall, because of changes in the length of daylight and changes in temperature, the leaves stop their food-making process. The chlorophyll breaks down, the green color disappears, and the yellow to orange colors become visible and give the leaves part of their fall splendor. At the same time other chemical changes may occur, which form additional colors through the development of red anthocyanin pigments. Some mixtures give rise to the reddish and purplish fall colors of trees such as dogwoods and sumacs, while others give the sugar maple its brilliant orange. The autumn foliage of some trees show only yellow colors. Others, like many oaks, display mostly browns. All these colors are due to the mixing of varying amounts of the chlorophyll residue and other pigments in the leaf during the fall season.Weather Affects Color Intensity - Temperature, light, and water supply have an influence on the degree and the duration of fall color. Low temperatures above freezing will favor anthocyanin formation producing bright reds in maples. However, early frost will weaken the brilliant red color. Rainy and/or overcast days tend to increase the intensity of fall colors. The best time to enjoy the autumn color would be on a clear, dry, and cool (not freezing) day. Enjoy the color, it only occurs for a brief period each fall.Section 8.3 Review Name:

Biology 6.0 Date: Period:

The Light-Dependent Reactions: Generating ATP and NADPH (page 235)For Questions 1–5, write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true. 1. Photosystems are clusters of chlorophyll and proteins. 2. The light-dependent reactions begin when photosystem I absorbs light. 3. Electrons from water molecules replace the ones lost by photosystem II. 4. ATP is the product of photosystem I. 5. ATP and NADPH are two types of protein carriers.

6. How does ATP synthase produce ATP?

7. When sunlight excites electrons in chlorophyll, how do the electrons change?

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8. Where do the light-dependent reactions take place?

9. Complete the table by summarizing what happens in each phase of the light-dependent reactions of photosynthesis.

Light-Dependent Reactions Description

Photosystem II

Electron Transport Chain

Photosystem I

Hydrogen ion movement and ATP Formation

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The Light-Independent Reactions: Producing Sugars10. What does the Calvin cycle use to produce

high-energy sugars?

11. Why are the reactions of the Calvin cycle called light-independent reactions?

12. Complete the diagram of the Calvin cycle by filling in the missing labels.

Photosynthesis involves two sets of reactions. The light-dependent reactions need sunlight. They use energy from this sunlight to produce energy-rich compounds, like ATP. The light-independent reactions use these energy-rich compounds to produce sugars from carbon dioxide.Complete the T-chart. Write the phrases in the box that belong in each side of the chart.

Light-dependent Reactions Light-independent Reactions

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Use energy from the sun Take place in the stromaUse carbon dioxide Take place in thylakoidsProduce oxygen Require waterProduce sugars aka Calvin cycleConvert ADP into ATP

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Photosynthesis Internet Activity Name:

Biology Date: Period:

A. Illuminating PhotosynthesisSite: http://www.pbs.org/wgbh/nova/nature/photosynthesis.htmlDirections: Read the Introduction “Illuminating Photosynthesis” By Rick Groleau

Click on the link “Launch Interactive” and read the introductory poem.

Click on “The Cycle” at the top of the box.

1. Click on each of the following items, and explain what happens:

a. The shade over the window:

b. The container of water:

c. The child:

2. a. What gas does the child provide for the plant to use?

b. What gas does the plant provide for the child to use?

c. Will the plant continue to produce this gas if the shade over the window is closed? (Try it to see)

3. According to this animation, what 3 main things does the plant need for photosynthesis to occur?

1.) _________________________________

2.) _________________________________

3.) _________________________________

Click “The Atomic Shuffle” at the top of the box, read the introductory poem, & click “next.”

4. What type of molecule is shown in the leaf? ________________________________________

5. Draw one of the molecules below, as it is shown in the leaf.

6. According to the reading, these molecules “do not come from the tap.” What 2 places do they come from?

1.) _______________________________ 2.) _______________________________

Click “next” and watch carefully. You may click “replay” to watch again.

7. a. What is “stripped” from each water molecule?

b. From where does the cell get the energy to do this?

c. The stripped molecules form pairs. Where does it go after this?

8. Click “next” What gas enters the leaf?

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This gas enters through “holes” in the leaf. What are they called?

9. Click “next”. What molecule is formed once again?

10. Click “next”. Another molecule is formed (“and boy it is sweet”). Draw and name this molecule below as

shown.

Click “Three Puzzlers” at the top of the box.

11. Answer each of the following questions, and explain in your own words.

a. Can a tree produce enough oxygen to keep a person alive? Explain.

b. Can a plant stay alive without light? Explain

c. Can a plant survive without oxygen? Explain.

B. Factors that affect the rate of Photosynthesis

Introduction:In this simulation, you will be looking at the production of oxygen as a plant photosynthesizes. This procedure can be accomplished by placing elodea plants in water with baking soda to provide carbon. The plant can then be exposed to varying intensities and colors of light. Oxygen is measured in the number of bubbles produced by the plant. This simulator addresses three factors that influence the rate of photosynthesis. Carbon dioxide availability, light intensity, and light color can all be adjusted in the simulator to determine how each of the factors affects the rate of photosynthesis.

Goal: 1. Determine the factors that affect a plant ability to photosynthesize2. Determine the optimal conditions needed for photosynthesis

Site: http://www.biologycorner.com/flash/waterweed.html

Questions1. In this investigation, how will you measure the rate of photosynthesis?

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2. Why would this procedure not work with a terrestrial plant?

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Question 1: How does the color of light affect the rate of photosynthesis?Directions:

1. Set the run speed to x52. Set the light level to 53. Set the CO2 level to 54. Run each filter color 3 times and average the result

What color(s) of light do plants absorb to photosynthesis (white is not a color of light)? Explain.

1. What color(s) of light do plants not need for photosynthesis? Explain

2. If white light contains all the colors of light (ROY G BIV) why did white light produce the most bubbles?

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Effect of Light Color on Photosynthesis

Light Color

Bub

ble

num

ber

Filter Color CountRun 1Run 2Run 3

Average =

Filter Color CountRun 1Run 2Run 3

Average =

Filter Color CountRun 1Run 2Run 3

Average =

Filter Color CountRun 1Run 2Run 3

Average =

3. If you had to design a light that only produced the colors that plants could absorb, what color would the plant appear?

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Question 2: How does the light level (intensity) affect the rate of photosynthesis?Directions:

1. Set the run speed to x52. Set the light color to colorless3. Set the CO2 level to 54. Clear the results from the last run

4. What data points prove that plants need light to photosynthesize?

5. What happens to a plants ability to photosynthesize as the light intensity increases?

6. According to your data, will there ever be a point where light intensity increases but the rate of photosynthesis remains constant? Explain.

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Effectct of Light Intensity on Pho-tosynthsis

Light Intensity

Bub

ble

num

ber

Light intensity (level) Bubble Count

0

2

4

6

8

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Question 3: How does CO2 affect the rate of photosynthesis?Directions:

1. Set the run speed to x52. Set the light color to colorless3. Set the light level to 54. Clear the results from the last run

7. What data points prove that plants need CO2 to photosynthesize?

8. What happens to a plants ability to photosynthesize as the CO2 concentration increases?

9. According to your data, will there ever be a point where carbon dioxide increases but the rate of photosynthesis remains constant? Explain.

10. Why do you think there is an upward limit to the amount of CO2 a plant needs for photosynthesis?

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Effectct of CO2 Level on Photosynthsis

CO2 Level

Bub

ble

num

ber

CO2 Level Bubble Count

0

2

4

6

8

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Light Reaction Web Activity Name:

Biology 6.0 Date: Period: To review the process of the light reaction view the animation at: http://www.csun.edu/~dsb40995/sed646-student.1/simulations/3.html

1. Label the following parts of the leaf on the image to the right:

Palisade MesophyllSpongy MesophyllEpidermisChloroplastCuticle

2. Label the following parts of the chloroplast on the image to the right:

StromaGranaThylakoid

Once you zoom in on the thylakoid membrane you will see five points of interest. Click on the points of interest to see what happens and answer the following questions.http://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html

3. What is used to energize the electrons in photosystem II?

4. What molecule supplies photosystem II with electrons?

5. What do the shapes between photosystem II and photosystem I represent?

6. What happened to H+ as the electron is passed through shapes between photosystem II and I?

7. What is used to re-energize the electrons at photosystem I?

8. What molecule is used to accept the high energy electrons produced at photosystem I?

9. Once the electrons are accepted by the electron carrier what molecule is created?

10. Describe the direction that H+ move through ATP synthase? (From the _________________ to the _________________)

11. What molecule is created when the H+ move through ATP synthase?

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Use the link below to view a simulation showing the light reaction of photosynthesis: Use the FireFox browserhttp://www.mhhe.com/biosci/genbio/biolink/j_explorations/ch09expl.htm Click “Skip Intro” to use the simulation and answer the questions.In the diagram on the right label the following:

Photosystem I Photosystem II Electron Transport Chain ATP Synthase Stroma Thylakoid Space / Lumen

1. Use the information from table 2 to predict the % maximal ATP at a light intensity of 220 lux.

2. What combination of light intensity and wavelength is necessary to reach the maximum ATP production?

3. What is the maximum ATP production?

4. What two molecules are produced by this process?

Click on the following website to view the Calvin Cycle (Light Independent Reactions)17

Table 1: The effects of wavelength on rate of light reaction

To complete the table set the light intensity at 100 lux and adjust the wavelength to the values on the table.

Table 2: The effects of light intensity on rate of light reaction

To complete the table set the wavelength at 650 nm and adjust the light intensity to the values on the table.

Wavelength (nm)

Approximate color of light

% Maximal ATP

400450500550600650700750

Light Intensity (lux) % Maximal ATP

0

40

80

120

160

200

http://www.science.smith.edu/departments/Biology/Bio231/calvin.html

This animation of the Calvin cycle is designed to show, in 3 stages, the major events in the synthesis of sugar in the stroma of chloroplasts.  For the sake of clarity all of the enzymes, except Rubisco, have been omitted and only the carbon skeletons of the intermediates are shown.

Go through each of the stages noting how the carbon molecules are converted through the cycle.3-PGA = 3-phophoglycerate

G3P = glyceraldehyde 3-phosphate

1. For every 3 CO2 molecules, how many 3-PGA molecules are formed?

2. For every PGA molecule, how many ATP molecules are used?

3. For every PGA molecule, how many NADPH molecules are used?

4. How many ATP molecules and NADPH molecules were used to convert the 3-PGA molecules to G3P

molecules? ATP NADPH

5. Of the 6 G3P molecules, only G3P is used to make sugar.

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Photosynthesis Review Questions Name:

Biology 6.0 Date: Period:

1. Identify the two main reactants of photosynthesis? Write the names and the formulas.

2. Identify the two main products of photosynthesis? Write the names and the formulas.

3. What is the main pigment of photosynthesis?

4. What is the main organelle that carries out photosynthesis?

5. Where do the light-dependent reactions take place?

6. Where do the light-independent reactions (Calvin Cycle) take place?

7. What do we call organisms that cannot make their own food?

8. What do we call organisms that use light energy to make food?

9. Which molecule loses electrons during photosynthesis?

10. Which molecule accepts electrons during photosynthesis?

11. Which two molecules synthesized by the light reactions are used in the Calvin Cycle?

12. What three things are produced when water splits?

13. The of light determines its color.

14. Chemicals that absorb light are called .

15. Chlorophyll makes plants look green because it green light.

16. Chloroplasts contain an abundance of saclike photosynthetic membranes called .

17. The is the fluid portion of the chloroplast located outside the thylakoids.

18. The visible light absorbed by chlorophyll the energy level of the chlorophyll’s

electrons.

19. How is ATP made in the light reactions?

20. What happens to the electrons that are lost by photosystem II? What happens to the electrons that are lost by photosystem I?

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21. What gas is fixed into carbohydrates during the Calvin Cycle?

22. Explain how the light reactions would be affected if there were no concentration gradient of protons across the thylakoid membrane.

Leaves contain chlorophyll and are the sites of photosynthesis in plants. Their broad, flattened surfaces gather energy from sunlight while openings on their undersides bring in carbon dioxide and release oxygen. The cells of a leaf are sandwiched in between two layers of epidermal cells, which provide the leaf with a waxy, nearly impermeable cuticle that protects against water loss. The only way for gases to diffuse in and out of the leaf is through small openings on the underside of the leaf, the stomates. These stomates can open and close according to the plant's needs.

Part A: Identify the function of the stomate.

Part B: Describe the benefits associated with having the ability to open and close stomates.

Part C: Explain why desert community plants would control their stomates differently than temperate climate community plants.

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