Chemistry Summer Camp - Day 1: Plant Pigments & Photosynthesis

Yesterday I posted an overview of the Chemistry summer camp I developed and hosted a few weeks ago in June. This camp was the first of 3 summer camps I put together for students in my school district as part of the STEP Summer Camp Series organized and sponsored by the Portage Education Foundation (PEF). The camps are generally free to attend for students within the district unless otherwise specified. The other two camps I am hosting are for middle school students and involve the CS First curriculum by Google (computer science, coding).


Today I will share the activity students did in the Chemistry summer camp on Day 1.


Day 1 consisted of an AP Biology lab exercise titled, “Plant Pigments and Photosynthesis.” My goal with this summer camp was to expose students to the chemistry of things around us - plants, food, batteries, fuel, etc. Fortunately, by studying plant pigments and photosynthesis, students were able to learn about and utilize common lab techniques. In the morning of Day 1, students separated the pigments of a spinach leaf through paper chromatography. Before doing the experiment, I provided a mini-lecture about chromatography, solvents, polarity, and chemical structure of the common pigments found in leaves. During the activity, most students were able to identify the 4 common pigments in leaves: carotene, xanthophyll, chlorophyll a, and chlorophyll b - based on color and position of the bands on the chromatography paper (polarity relative to the solvent). Students were also able to successfully calculate the Rf values for each pigment that was present.



Next, students compared the light reactions of photosynthesis of chloroplasts under varying conditions using a spectrophotometer (Spec-20). One of the challenging components I experienced in setting up this lab was finding enough heat lamps in the chemistry lab. There were 6 groups of students working that day but only 3 or 4 heat lamps. This forced students to share set ups with one another.




The purpose of the heat sink was to have certain samples receive light without the addition of the infrared radiation from the heat lamp. The setup seemed to work well.





Overall, students seemed to enjoy the first day’s activities. We finished the photosynthesis activity after lunch and still had about an hour before camp was finished for the day - so I provided a mini-lecture aimed at preparing them for the limonene extraction lab on Day 2 at Kalamazoo College.