LIFESCI 7A Lecture Notes - Lecture 5: Photosynthetic Pigment, Light-Independent Reactions, Photic Zone
Document Summary
Photosynthesis: biochemical process for building carbohydrates using energy from sunlight and carbon dioxide taken from air. The carbs are used as starting point for synthesis of other molecules and energy storers that can be converted to atp by cellular respiration. Major entry point for energy into biological systems--source of all food we eat. Photosynthesis occurs in prokaryotic and eukaryotic, land and sea: most photosynthetic organisms in marine environment are unicellular. Photosynthesis occurs in surface layer up to 100m deep (photic zone) Carbs are synthesized from co2 during photosynthesis, but have more energy stored in bonds than is contained in bonds of co2--> building carbs using co2 requires input of energy from sunlight. Energy from sunlight is used to produce atp and e- donors (nadph) capable of reducing co2. E- donor is water--oxidation of water forms electrons, protons, o2. Oxygen is a by-product of water being a source of e-
