Sugar and Cellular Respiration (Joshua Junkermeier)
NGSS Standards
HS-LS1-6
HS-LS1-7
Scientific Problems
1. What foods are best for producing quick, dependable energy?
2. How do the foods we eat help the body?
3. What foods ensure higher fitness and weight management?
4. How does the body and body-systems use food to produce
energy and perform functions?
Introductory activity (adapted)
two sugar cubes
apply flame to both and observe results
generate a model to hypothesize/explain your observations
share out: hypothesis', models, and inferences
watch glycolysis video
modify models and inferences as needed.
video demonstration:
Glycolysis Video:
Extensions: phet chemical reactions
Principles Illustrated:
Sugar is a source of energy/fuel in or outside of the body.
Sugar will not readily produce energy (flame) without the the presence of a catalyst
The ash functions as a catalyst (analogy). Similarly, the chemical reactions specific to cellular respiration require multiple enzymes at specific stages of specific processes to function as catalysts.
Catalysts reduce the activation energy of a chemical reaction. This allows reactions to occur at a higher rate and with little or no additional input of energy in or outside of the body.
Principles Illustrated:
Sugar is a source of energy/fuel in or outside of the body.
Sugar will not readily produce energy (flame) without the the presence of a catalyst
The ash functions as a catalyst (analogy). Similarly, the chemical reactions specific to cellular respiration require multiple enzymes at specific stages of specific processes to function as catalysts.
Catalysts reduce the activation energy of a chemical reaction. This allows reactions to occur at a higher rate and with little or no additional input of energy in or outside of the body.
Prior Knowledge & Experience
This lesson may function as a "hook" demonstration into the concept of enzymes and molecular-level of an organism. This lesson would fit in well to reinforce students developing understanding of proteins or enzymes in the body.
The lesson functions well assuming the students understand food provides energy for the body, but have not completed their investigations of the different processes of cellular respiration: Glycolysis (discussed as follow-up process in this lesson), Citric Acid Cycle, and Electron Transport Chain.
In short, based on teacher sequencing, this lesson can be adapted to function as an introduction to Cellular Respiration.
This lesson can reinforce concepts within Cellular Respiration or the molecular-basis of life (elements/molecules/polymers/glucose/proteins/lipid and their role in the body)
Target Response:
If an introduction into enzymes or proteins, then students will generate numerous models to explain the role of ash.
If an introduction into cellular respiration, students may already remember proteins/enzymes can function as catalyst.
Common Misconceptions:
Students may not know what will or won't burn
Students may be surprised sugar will continue to burn under proper conditions
Students may not understand sugar or other foods store or release energy as a reactant in a chemical reaction.
Students may generate incomplete models or misconceptions in their explanatory models.