Academic Standards - Purdue ASEC 3_… · Web viewThe performance of photosynthetic organisms, such as plants, algae, and many bacteria, depends on the earth's atmosphere and climate

By Matt Kararo, Melissa Voigt, Kathryn Orvis©Purdue University, 2016

CenUSA Bioenergy High School CurriculumJanuary, 2016

Lesson 3: PhotosynthesisThis lesson covers photosynthesis. Student will need this knowledge to complete labs and research in following lessons. Lessons are designed for 10th-12th grade students. This lesson was designed for a block schedule; however, it may be shortened and edited to suit the teacher, the material, and the class. This material may also be used in other agricultural classes.

Learning ObjectivesAt the end of this lesson, students will be able to successfully achieve the following objectives:

1. Describe photosynthesis and the basic steps involved in the process.2. List three environmental factors that affect photosynthesis.3. Explain how photosynthesis fits in the carbon cycle.

Academic StandardsDomain: Emerging Technologies (Sustainable Energy Alternative)Core Standard 6: Students apply and adapt photosynthesis and respiration in plants to make

decisions on plant production. Indiana State Standard: PSS 6.1-6.3National AFNR Standards: CS.02.04; CS.03.03; PS.02 Next Generation Science Standards: HS-LS1-5, HS-LS1-6, HS-LS1-7, HS-2-3, HS-LS2-4, HS-LS2-5

Documentation of Competencies Met by This LessonConnection to SAE/Career Development: Agriscience Research - Plant Systems, Emerging

Agricultural Technology, Diversified Crop – Entrepreneurship, Diversified Crop – Placement, Diversified Horticulture

Connection to FFA/Leadership Development/Personal Growth: Anything that involves working with new and emerging technology, diversified crop production, specialty crop production, educating the community about bioenergy, and continuing education.

Kararo, Voigt, Orvis ©Purdue Page 1 January 2016This project is supported by Agriculture and Food Research Initiative Competitive Grant No. 2011-68005-30411 from the National Institute of Food and Agriculture.

CenUSA Bioenergy High School Curriculum January, 2016

Curriculum Content IncludedSupplies Needed........................................................................................................................................3

Teaching Content and Learning Activities..................................................................................................4

3.1 Introduction to Photosynthesis.......................................................................................................4

Learning Activity................................................................................................................................ 4

Teaching Content...............................................................................................................................4

3.2 Processes of Plant Growth Photosynthesis......................................................................................4


3.3 Lab: Photosynthesis: What are the true colors of leaves?...............................................................6

Description........................................................................................................................................ 6

Learning Objective.............................................................................................................................6

Time Requirement.............................................................................................................................6

Supplies............................................................................................................................................. 6

Control and Variables........................................................................................................................6

Warning............................................................................................................................................. 6

Directions...........................................................................................................................................6

Discussion.......................................................................................................................................... 7

3.4 Transpiration................................................................................................................................... 7


Lesson 3: Student Review Questions.........................................................................................................8

Lesson 3: Student Review Questions - KEY................................................................................................9

Lesson 3: Teacher Assessment................................................................................................................ 10

Supplemental Documents:Lesson 3 PowerPoint PresentationLesson 3 Print Outs

Supplies Needed• Tape • Pencil • Small clear jar

Orvis, Kararo, Long ©Purdue Page 2 August 2014


• Coffee filters, cut 2-3 cm wide into approximately 10 cm long strips (depending on jar size)• Rubbing alcohol • Assortment of leaves and petals

Teaching Content and Learning ActivitiesNotes.

A PowerPoint presentation is included with this curriculum and includes the follow teaching content and learning activities. You may modify the presentation as needed for your class.

The teaching content and learning activities are presented here in the suggested order of occurrence.

3.1 Introduction to Photosynthesis

Learning Activity

DirectionsAsk the students to list on a piece of paper what they know about photosynthesis, the products of photosynthesis, and the importance of photosynthesis to life. After three minutes, ask students to share their thoughts. Allow the discussion to flow into the objectives of the lesson.

Teaching Content



Photosynthesis (see simplified figure above, does not show reduced electrons; based upon an existing diagram) is a physicochemical (relating to physical chemistry) process by which plants, algae and photosynthetic bacteria (bacteria that have the capability of producing energy using photosynthesis) use light energy to drive the synthesis of organic compounds used by the organism for chemical energy. Photosynthesis results in the release of oxygen and the removal of carbon dioxide from the atmosphere.

The process of photosynthesis provides the chemical energy and the recycling of carbon dioxide required for the survival of virtually all life on our planet. Additionally, this process provides the oxygen necessary for the survival of organisms such as mammals, birds, fish, and insects.

The performance of photosynthetic organisms, such as plants, algae, and many bacteria, depends on the earth's atmosphere and climate. When you breathe, your body uses oxygen (O2) and gives off carbon dioxide (CO2).

The steps or equation for the photosynthetic process is 6CO2 + 6H2O (Water) 6O2 + C6H12O6 (Glucose) (see diagram below). This process requires six carbon dioxide (CO2) molecules and six water (H2O) molecules to make six oxygen (O2) molecules and one glucose (sugar) molecule (C6H12O6). Chlorophyll and sunlight are required for the process to occur.


http://www.ck12.org/book/CK-12-Biology/r44/section/4.2/)


3.2 Processes of Plant Growth

Teaching ContentThe process of capturing light energy and converting it to sugar energy (glucose) happens in the chloroplasts of the plant, which are tiny sub-cellular structures in the cells of leaves and green stems. In the presence of chlorophyll, carbon dioxide and water react with the sun’s energy to form photosynthates (sugars, starches, carbohydrates, and proteins) and release oxygen as a byproduct. This occurs only in the chloroplasts and is directly dependent on the supply of water, light, and carbon dioxide.

The process of photosynthesis is split into two separate reactions referred to as the light dependent reaction and the light independent reaction. These reactions occur in the stroma of the plant. The light dependent reaction happens when sunlight is captured and is used to begin the process of photosynthesis. This first reaction results in the creation of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). ATP is a free energy containing molecule and is produced through a chain of steps starting when chlorophyll absorbs light energy. NADPH is used as a reducing agent in the Calvin cycle reactions, meaning that it donates electrons to other molecules.

The light independent reactions create glucose through the Calvin cycle. The Calvin Cycle uses ATP and NADPH to turn carbon dioxide into glucose. The light dependent reactions sustain the Calvin Cycle by regenerating the ATP and NADPH.

There are three phases in the Calvin Cycle:

Phase I. Carbon FixationDuring the first phase of the Calvin Cycle, CO2 is incorporated into a five-carbon sugar molecule called ribulose bisphosphate (RuBP). The enzyme which catalyzes this first step of the Calvin Cycle is RuBP carboxylase or rubisco. Rubisco is the most abundant enzyme protein in chloroplasts.



Phase II. ReductionDuring the second phase of the Calvin Cycle, ATP and NADPH from the light reactions are used to convert 3-phosphoglycerate to glyceraldehyde 3-phosphate, the three-carbon carbohydrate precursor to glucose and other sugars.

Phase III. RegenerationDuring the third phase of the Calvin Cycle, more ATP is used to convert some of the glyceraldehyde 3-phosphate back to RuBP, the acceptor for CO2, completing the cycle.

Simplified Calvin Cycle

The simplified diagram of the Calvin Cycle shows how sugars are created by plants. So after the sugar is created, what is it used for? The answer is energy to grow and the “how” is through a process called respiration. Respiration is the counterpart to the photosynthetic process. Energy is created during respiration by converting sugars and oxygen back into water and carbon dioxide. One process that animals and plants have in common is respiration. We will not be covering this concept in detail, but just know that respiration is the counterpart to photosynthesis.



3.3 Lab: Photosynthesis: What are the true colors of leaves? Modified from:

Photosynthesis and Biomass Growth. (2014, June 18). Retrieved August 26, 2015, from http://energy.gov/sites/prod/files/2014/06/f16/biomass_photosynthesis.pdf

DescriptionThis experiment uses chromatography techniques to separate pigments found in leaves. The techniques used should result in students being able to distinguish three different pigments: chlorophyll, carotenoids, and anthocyanins.

BackgroundChlorophyll and its role in photosynthesis was discussed in depth earlier in this lesson, but now it is time to introduce two other players into the game: carotenoids and anthocyanins. These two pigments complement chlorophyll and have their own roles to play in the photosynthetic process. Carotenoids absorb different wavelengths of light than chlorophyll, and transfer that light to chlorophyll in order to allow light dependent reactions to be powered by a wider spectrum of wavelengths. Anthocyanins act as a light blocking pigment, absorbing shorter wavelengths of light (violet and ultraviolet) in order to prevent light stress, which can occur in plants during times of intense sunlight.

Learning ObjectiveStudents will be able to:

Demonstrate an understanding of extraction methods for the three main groups of plant pigments (chlorophyll, carotenoids and anthocyanins) and their functions.

Categorize plant pigments based upon their visual appearance (chlorophyll [green], carotenoids [yelloworange] and anthocyanins [blue-red]).

Time RequirementApproximately [#] minutes.

Supplies Tape Pencil Small clear jar Coffee filters, cut 2-3 cm wide into approximately 10 cm long strips (depending on jar size) Rubbing alcohol Assortment of leaves and petals

Control and VariablesControl: Rubbing alcohol solvent Variables: Variety of plant material


http://energy.gov/sites/prod/files/2014/06/f16/biomass_photosynthesis.pdf


WarningUse caution when using alcohol! It is flammable and should not be splashed into eyes or on skin. Goggles, gloves and a protective lab coat are needed!

Directions1. Fill a jar with rubbing alcohol until it reaches approximately 1.5-2 cm in height.2. Choose a leaf or petal and place it upside down on a hard surface.3. Place a filter strip on the leaf or petal, making sure that there is 2 cm of the filter strip NOT on

the leaf or petal.4. With the cap-end of a pen, gently rub on the part of the filter strip that is on the leaf or petal.

This will transfer the pigment of the leaf or petal onto the filter strip. Make the rubbing approximately the size of a penny. Readjust the leaf and continue rubbing until the spot on the filter strip is dark.

IMPORTANT: Do not use the ink or lead of a pen or pencil or an eraser to rub the filter as this will disrupt the results of this lab.

5. Carefully place the filter strip in the jar with rubbing alcohol. The area on the filter strip with the transferred pigment should be above the solvent level with about 1 cm of the filter strip in the solvent. Use a piece of tape to secure the filter strip to the jar.

6. Once the solvent (a.k.a. rubbing alcohol) reaches the top of the filter strip, remove the strip and allow it to dry.

7. Compare the dried filter strips from different leaves and petals.

DiscussionDiscuss the fact that the reds, yellows, and oranges that we see in the fall are always present in leaves, but are obscured by the green of chlorophyll in the spring and the summer. Green bananas also show chlorophyll. As the chlorophyll breaks down, the yellow pigments can be seen.

3.4 Lab: TranspirationModified from:

Whiting, D., Roll, M., & Vickerman, L. (2014, October). CMG GardenNotes #141 Plant Physiology: Photosynthesis, Respiration, and Transpiration. Retrieved August 26, 2015, from http://www.ext.colostate.edu/mg/Gardennotes/141.pdf

DescriptionThis experiment uses a real-world example along with a computer simulation to investigate transpiration. Although this lab can be completed in one day, results for the real-world example will be more discernable if the activity takes place over multiple days.

BackgroundTranspiration is the loss of water vapor through the stomata on leaves (see figure below). During the process of transpiration, besides the interchange of carbon dioxide, oxygen, and water vapor, there is upward movement of minerals from the plant’s roots (in the xylem) and movement of sugars (products


http://www.ext.colostate.edu/mg/Gardennotes/141.pdf


of photosynthesis) throughout the plant (in the phloem). Water serves as both the solvent and the avenue of transport in this process.

Image from University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu)

Turgor pressure is the pressure of water in the vacuole pushing the plasma membrane against the plant cell wall. It is a part of the transpiration process. Water maintains the turgor pressure in cells much like air inflates a balloon, giving the non-woody plant parts form. Turgor pressure causes a plant to be stiff and upright. It is important for the functioning of the guard cells, which surround the stomata, can open and close the stomata, and therefore regulate water loss and carbon dioxide uptake. If a plant has a low turgor pressure, transpiration can be disrupted. There are multiple factors that can impact the rate of transpiration and therefore the turgor pressure of a plant, some of which will be investigated in the following activity.

Learning ObjectivesStudents will be able to:

List the three main factors associated with the rate of transpiration. Explain how those three factors each can impact the rate of transpiration.

Time RequirementApproximately [#] minutes.

Supplies Non-succulent house plants Small plastic sandwich bags



Twist ties Gram scale

Directions1. Obtain multiple non-succulent houseplants of the same species and variety (however many can

be obtained is not crucial as long as it is more than one).2. Have students weigh a small sandwich bag on the gram scale and record the results.3. Choose similar branches or stems on each plant (the key is the same or similar number of

leaves).4. Place a sandwich bag over the previously determined branch or stem on each plant, securing

with a twist tie.5. Place one of the plants in a sunny window; other plants should go in other locations, for

example, a dark corner, a closet, in front of a fan, etc.6. Have students estimate and record the variables present for the different plants (e.g. wind

speed, light saturation, temperature).7. After a period of time (can be an hour, a school day, or up to a week) have the students

carefully remove the bags from the plants and weigh them again on the gram scale, matching the initial values to the current values and comparing how much water was lost through transpiration.

DiscussionDiscuss how much of a difference there was between the transpiration rates of the plants that were placed in different locations. Discuss the different variables that were present and have students try to explain how the variables impact rates of transpiration. Bring up this virtual lab and have students hypothesize how the different factors will impact transpiration and see if they are correct: http://www.mhhe.com/biosci/genbio/virtual_labs/BL_10/BL_10.html


http://www.mhhe.com/biosci/genbio/virtual_labs/BL_10/BL_10.html


Lesson 3: Student Review Questions

Name: _______________________________ Date: ___________________________________

Select T/F for the questions listed below:

1. __________ Plants, algae, and some bacteria are capable of creating energy from sunlight.

2. __________ Chemical formula for photosynthesis: CO2 + H2O (water) O2 + C6H12O6 (glucose)

3. __________ When you breathe, your body uses oxygen (CO2) and gives off carbon dioxide (O2)

4. __________ Turgor pressure – Water maintains the turgor pressure in cells much like air inflates a balloon, causing non-woody plant parts to curl.

5. __________ The light independent reaction happens when sunlight is captured and used to begin the process, resulting in the creation of ATP.



Lesson 3: Student Review Questions - KEY

Name: ___ MASTER KEY _____________________ Date: ______________________

Select T/F for the questions listed below:

1. ____T______ Plants, algae, and some bacteria are capable of creating energy from sunlight.

2. ____T______ Chemical formula for photosynthesis: CO2 + H2O (water) O2 + C6H12O6 (glucose)

3. ____F______ When you breathe, your body uses oxygen (CO2) and gives off carbon dioxide (O2)

4. ____F______ Turgor pressure – Water maintains the turgor pressure in cells much like air inflates a balloon, causing non-woody plant parts to curl.

5. ____F______ The light independent reaction happens when sunlight is captured and used to begin the process, resulting in the creation of ATP.



Lesson 3: Teacher Assessment

As the teacher, reflect on the Lesson 3 and answer the following questions.

1. What did the students like about this lesson?

2. What did the students dislike about this lesson?

3. Did the students find anything difficult in this lesson? If so, what?

4. What are the strengths of this lesson?

5. What are the weaknesses of this lesson?

6. What went well during this lesson?

7. What did you find difficult or challenging during this lesson?

8. Where the objectives met effectively during this lesson?

9. Were the labs or activities relevant to the lesson topic?

10. Overall, do you have any other suggestions or thoughts about this lesson?
