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The Arizona STEM Acceleration Project

Photosynthesis Lab Series

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Series of Photosynthesis Labs

A 7-12 grade STEM lesson�for Biology

Hermelina Liddell

January 21, 2024

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Notes for teachers

In this lesson, students will learn the details of photosynthesis by performing a series of labs to observe the following:

1. Chloroplast

2. Presence of glucose

3. Spectral analysis

List of Materials:

Lab 1 Chloroplast

Microscope

Microscope slides

Onion

Elodea leaf

Tweezer

Lab 2 Glucose

Ethyl alcohol

Iodine solution

Test tubes

Hot plate

Forceps

Petri dish

Lab 3 Spectral Analysis

SpectraVis-Plus spectrophotometer

Spinach 70% isopropanol

Zip lock bag/coffee filter

Beaker

Computer

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Standards

AZ Science Standards

Essential HS.L2U1.21 Obtain, evaluate, and communicate data showing the relationship of photosynthesis and cellular respiration; flow of energy and cycling of matter.

Plus HS+B.L2U1.8 Develop and use models to develop a scientific explanation that illustrates how photosynthesis transforms light energy into stored chemical energy and how cellular respiration breaks down macromolecules for use in metabolic processes.

NGSS: HS-LS1.C.3

As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Standards

Science and Engineering Practices:

  • Asking questions and making predictions
  • Plan and cary out investigation
  • Analyze and Interpret data

Crosscutting Concepts:

Structure and Function

  • Stability and Change
  • Matter and Energy
  • Structure and Function

ISTE Standards

Empowered Learner

Knowledge Constructor

NGSSHS-LS2-3.

Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions.

LS2.B: Cycles of Matter and Energy Transfer in Ecosystems

  • Photosynthesis and cellular respiration (including anaerobic processes) provide most of the energy for life processes.

 

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Objective(s):

Learning Target:

We are learning to investigate the role of chloroplast in photosynthesis, the presence of Carbon and spectral analysis in leaves.

Success Criteria

    • I can observe chloroplast in leaves and explain why they move.
    • I can investigate for the presence of glucose in a leaf sample.
    • I can do spectral analysis using a spectrophotometer by collecting an absorbancy vs wavelength data.

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Agenda (2-3 days of 50 min)

Bell work (5-10 min)

Phenomenon (5 min)

Review

Factors Limiting Photosynthesis

Pre Lab

Lab 1 30 min

Lab 2 30 min

Lab 3 30 min

Analysis (5 min)

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Bell work

Bell work (5-10 min)

Observe:

Blow in air in a test tube with Bromothymol blue.

What happens? What does the color change indicate?

How does Carbon enter the leaves in plants?

This Photo by Unknown Author is licensed under CC BY-SA

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Phenomenon

Why do

sunflowers

face the

morning

sun?

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Review

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Introduction:�

Activate Prior Knowledge

  1. Photosynthesis Overview
  2. The Chemical Process
  3. The Leaf Structure: The Chloroplast/Chlorophyll

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Driving Questions�

1. What is the chemical equation for Photosynthesis?

2. Why are leaves green?

3. Why do chloroplasts move?

4. What factors affect photosynthesis?

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Introduction

Introduction to the Lab Activity

(Optional: You can do your own introductory lesson on photosynthesis)

Photosynthesis Interactive

Photosynthesis (hhmi.org)

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Hands-on Activity Instructions

Lab 1

Prepare a Plant Cell slide

Students prepare a plant cell slide and observe the chloroplast

  • plant cell lab.docx

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Hands-on Activity Instructions

Lab 2

Test for Glucose

Students examine if glucose is present in leaves

Photosynthesis Test for Starch Lab.docx

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Hands-on Activity Instructions

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Integrating Technology

Lab 3

Spectral Analysis

Students use a spectrophotometer to collect absorbance vs wavelength data

Spectral Analysis Lab.docx

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Assessment

Lab Analysis Questions are included in the Lab Procedures

Post Lab Activities: (optional)

1. How to prepare a slide/mount a sample on the slide

2. Iodine solution is corrosive. What do you mean by that?

3. In what other ways can you use the spectrophotometer?

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Differentiation

1. One-on-one demonstration

2. Working with a partner

3. Videos for safety

4. Instead of the interactive video on HHMI, edpuzzle has shorter video clips with pauses so students can answer questions and check for understanding.

Remediation

Extension/Enrichment

Students can collect other data using the spectrophotometer.

Use other leaf samples and notice which wavelengths have the highest or lowest absorbance.

They can save the data they collected.

Students can also examine leaves that are purple.