This unit was taught in a college preparatory class to mostly freshman and sophomores. The units leading up to this were the following: Scientific Methods, Chemistry of Life, Cell Structure and Cell Processes, Mitosis, Ecology (Energy Flow, Biogeochemical process, Biomes). The Unit Objectives and Exam (not provided) were developed in collaboration with the other biology instructors at the school. While the unit focuses upon photosynthesis and respiration, instruction drew upon student prior learning of biogeochemical cycles. The goal of our Triad unit was threefold: 1) to contextualize learning within a relatable phenomenon, 2) to motivate students to understand the complicated processes of photosynthesis and cellular respiration, while grasping their place in the fabric of life, and 3) to help students understand the interactions between micro (photosynthesis and respiration) and macro (biogeochemical cycles) systems.