Jim Bidlack - BIO 1304 GENERAL BOTANY Lecture 10 - Photosynthesis (Part II) IV. (Continued from last time) Dark reactions A. Major purpose - use energy from light reactions to fix CO 2 into organic molecules B. Reagents of dark reactions 1. ATP and NADPH 2. CO 2 3. Ribulose bisphosphate 4. Enzymes (especially RUBISCO - Ribulose bisphosphate carboxylase / oxygenase) C. Why fix CO 2 ? 1. Store and use chemical energy in the form of organic compounds D. Steps of CO 2 fixation: 1. CO 2 and H 2 O (1 carbon) are added to ribulose bisphosphate (5 carbons) to form two molecules of 3-phosphoglyceric acid (3-PGA) (total of 6 carbons) 2. Catalysis of this reaction by RUBISCO 3. 3-PGA is reduced to 3-PGAL with the help of NADPH and ATP 4. 3-PGAL is converted to either fructose diphosphate or, eventually ribulose bisphosphate 5. Fructose diphosphate goes to other aspects of metabolism and ribulose bisphosphate goes
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This note was uploaded on 03/27/2012 for the course BIO 1304 taught by Professor Bidlack during the Fall '10 term at University of Florida.