Ms. Rosendo Biology (10th Grade) Photosynthesis Ms. Rosendo Biology (10th Grade)

Objectives Describe the photosynthesis reaction in detail. Mention the molecules involved in the reaction process. Identify the types of chlorophyll present in plants. Establish the importance of the photosynthesis process and photosynthetic organisms.

Photosynthetic Organisms The sun is the primary energy source that maintains all life forms. Photosynthesis is a process that transforms solar energy into chemical energy. This energy is then stored in carbohydrates and/or lipids. Only 2% of the 42% of solar energy that reaches the planet, is captured by photosynthesizers.

Photosynthesis and light

Photosynthesis and light

Chlorophyll and other pigments Chlorophyll a (680nm) Photosynthetic eukaryotes and cyanobacteria ¾ of the total content of chlorophyll Involved in the production of oxygen. Chlorophyll b (650nm) Plants, green algae and euglenoids Accessory Augments the spectrum of absorption Energy that transfers to chlorophyll a

Chlorophyll and other pigments Chlorophyll c Some brown algae and diatoms Similar function of the chlorophyll b. Carotenoids All chloroplast and cyanobacteria Carotenes and xanthophyll’s Antioxidants Phycobilin Cyanobacteria and red algae

Photosynthesis Equation light 3CO2 + 6 H2O → C3H6O3 + 3O2 + 3H2O

Reactions

Reactions that involve light

Photosystems

Photosystems Photosystem 1 Photosystem 2 P700 Strome thylakoid or external thylakoid of the grana. Photosystem 2 P680 Grana thylakoid

Non-cyclic phosphorylation

Cyclic phosphorylation

Electron Transfer

Dark Reactions

Calvin Cycle: Phase 1

Calvin Cycle: Phase 2

Calvin Cycle: Phase 3