The reactions of the Calvin Cycle are energy requiring. The energy used to drive the Calvin Cycle is derived from a series of reactions whose products provide the energy necessary. The Calvin Cycle is the series of reactions in which carbon is fixed. Look for summaries of the Light Dependent and Light Independent Reactions on the Bio 20 Web Page. Green plant cells contain organelles called chloroplasts .
Light energy is channeled to a reaction center.
A pair of electrons from the chlorophyll molecule in the reaction center is elevated to a high energy state. Chloroplast Structure Chlorophyll is a light absorbing lipid situated in the centers of reaction centers in the photosynthetic membranes of green plants. It consists of a porphyrin ring with a Magnesium atom at the center. Chlorophyll-a is one example of a photosynthetic pigment. The electrons pass into a second reaction center , Photosystem I .