Sweet Beets: Making Sugar Out of Thin Air

By Sarah R. Sletten

Abstract

This directed case study introduces students to photosynthesis and illustrates how biology plays a vital role in the carbon cycle and the conversion of energy. Set in North Dakota along the Red River of the North, the case uses the sugar beet (Beta vulgaris) as a model organism for learning about the process of photosynthesis. The case begins by introducing the sugar beet growing season and the plant's anatomy. Students are provided information specific to photosynthesis in sugar beets and are then asked to explore the process in general. Atmospheric carbon dioxide levels are provided, and after comparing levels between sugar beet growing seasons, students should come to realize that sugars are made from the carbon found in atmospheric carbon dioxide. The case is designed for use in a "flipped" classroom, where students prepare in advance by viewing a number of videos, including one created by the author of the case. Quiz sheets for the recommended videos are included in the teaching notes.

Download Case

Date Posted

09/28/2015

Overview

Objectives

Describe the functions of the leaves and roots of the sugar beet plant.
Illustrate the basic process of photosynthesis.
Construct and interpret graphs of carbon dioxide concentrations and relate them to growing seasons.
Conclude that sucrose is made from carbon dioxide through the process of photosynthesis.

Keywords

Photosynthesis; carbon fixation; Calvin cycle; carbon cycle; chloroplast; sugar beet; agriculture; Beta vulgaris; Red River

Subject Headings

Agriculture

Biology (General)

Environmental Science

EDUCATIONAL LEVEL

High school, Undergraduate lower division

FORMAT

PDF

TOPICAL AREAS

N/A

LANGUAGE

English

TYPE/METHODS

Analysis (Issues), Directed, Flipped

Teaching Notes & Answer Key

Teaching Notes

Case teaching notes are protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, purchase a subscription here.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Download Notes

Answer Key

Answer Keys are protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, purchase a subscription here.

Download Answer Key

Materials & Media

Supplemental Materials

Videos

Sweet Beets
This video provides footage from an actual sugar beet field and the beet stockpiles that will make the case more relatable. There is also a basic introduction to photosynthesis in the video that will help prepare students for Part IV of the case study. Created by Sarah R. Sletten for the National Center for Case Study Teaching in Science, 2015. Running time: 4:01 min.
Photosynthesis: Fun in the Sun
Got oxygen? Got food? Well, then you've got to have photosynthesis! This video breaks down photosynthesis into the “photo” part (capturing light energy and storing it) and the “synthesis” part (fixing carbon into carbohydrates). Created by The Penguin Prof, 2012. Running time: 14:36 min.
Photosynthesis
This video explains the process of photosynthesis by which plants and algae can convert carbon dioxide into useable sugar. It begins with a brief description of the chloroplast. It describes the major pigments in a plant (like chlorophyll a and b). It then describes both the light reaction and the Calvin cycle. It finishes with a discussion of photorespiration and strategies for avoiding this problem evolved in CAM and C4 plants. Created by Paul Andersen/Bozeman Science, 2012. Running time: 12:26 min.
Photosynthesis: Crash Course Biology #8
This video explains the extremely complex series of reactions whereby plants feed themselves on sunlight, carbon dioxide and water, and also create some byproducts we’re pretty fond of as well. Created by Crash Course, 2012. Running time: 13:14 min.