Teachable Tidbit: Energy Transformations in Plants (Photosynthesis and Respiration) Alexie McNerthney, Annie Crater (Portland Community College) Benjamin Simon, Lalita Calabria, Lauren Troyer, Richard Weiss (The Evergreen State College) Biology/Chemistry Interface: Teachable Unit

Learning GoalsLearning OutcomesSummative Assessment Formative Assessment Understand the processes of energy transformation in plants Understand the scientific process Understand the role of plants in the global carbon cycle Compare and contrast photosynthesis and respiration Formulate hypotheses and interpret results Explain how changes in plant biomass affect carbon flow Interpret a graph comparing [CO 2 ] in plants treated with herbicides targeting metabolic processes. Diagram the carbon cycle Students develop a hypothesis from observations of herbicide effects on plant growth. Work in groups to predict effects of global plant biomass (or atmospheric CO 2 ) Biology/Chemistry Interface: Teachable Unit

Context Topics explored previously in this Introductory Biology or Plant Biology class –Structure and function of chloroplasts and mitochondria –Role of chemiosmosis –Potential and chemical energy conversions –Reactants and products for photosynthesis –Reactants and products for respiration

Learning Outcomes Compare and contrast photosynthesis and respiration –Which processes are common to both plants and animals –Which processes are unique to each Practice using the scientific method to: –Form a hypothesis –Interpret data

Scenario: You are a farmer trying to eliminate an invasive plant on your farm but you don’t want to kill the beneficial pollinating insects like bees and moths. You tested two chemicals for effectiveness. Product 1 killed the plants, but also killed insects. Product 2 killed only the plants. Generate hypotheses to explain these observations. Be prepared to share your reasoning behind your hypotheses. (5 minutes) (Discuss with small groups)

You apply the different herbicides to germinating seeds. Product 1 targets which metabolic process that is not targeted by product 2? Product 1Product 2 Control C. respiration D. regeneration of Rubisco A. chemiosmosis B. photosynthesis E. ATP production (Formative Assessment)

You apply the different herbicides to germinating seeds. Product 1 targets which metabolic process that is not targeted by product 2? Product 1Product 2 Control C. respiration D. regeneration of Rubisco A. chemiosmosis B. photosynthesis E. ATP production (Formative Assessment) Why is the answer “C” and not “A” or “E”? …A and E both occur in mitochondria also.

(Summative Assessment) Your neighborhood wants to use a product to control dandelions at the park without harming the animals. Experimental data on the two products are shown below. CO 2 concentration in leaves was measured after different treatments (red arrow). When interpreting the graph below recall that atmospheric CO 2 concentration is about 390 ppm. Which product would you want to use? Note: could be a free answer or sequential t/f question

You are a restoration ecologist at a local prairie. You are trying to eliminate an invasive grass that is outcompeting native grasses. In the trials you tested two herbicides for effectiveness. Herbicide 1 killed the grass, but also killed an endangered butterfly. Herbicide 2 killed only the grass. Generate hypotheses to explain these observations. Be prepared to share your reasoning behind your hypotheses. (5 minutes) Alternate Scenario