Chapter 11 Phototrophic Energy Metabolism Photosynthesis Photosynthesis the

Chapter 11 Phototrophic Energy Metabolism: Photosynthesis

Photosynthesis: the conversion of light energy to chemical energy. Phototrophs : are organisms that convent energy solar energy to chemical energy in the from of of ATP. Phtotrophs: photoheterotrophs, photoautotroph * the chloroplast : A photosynthetic organelle. *plant cells contain chloroplast.

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Chloroplasts are composed of there membrane system: * Outer membrane and inner membrane and separated by a narrow inter membrane space. * The inner membrane encloses the stroma a gel -like matrix teeming with enzymes for carbon nitrogen and sulfur assimilation * The outer membrane contains porius.

Chloroplasts have a third membrane systems: *Thylakoids : are flat saclike structures suspended in the stroma and usually arranged stacks called grana. *Grana: which resemble stacks of coins are interconnected by a network of longer thylakoids called stroma thylakoid.

photosynthesis • - Mitochondrion is an interconnected networks rather than discrete organelles by E. M. • - Mitochondrion has 0. 5 -1. 0 micro meter across and several micrometer length, various shape and size. • - Fluorescent microscope: mitochondria are dynamic and may fuse together. • - Outer & inner membranes define 2 separate compartments. • - Outer membrane is permeable to ions & small molecules (5000 Dalton) by porins. • - inter membrane space has cytosol (but has specific enzymes + proteins).

photosynthesis • - Inner membrane: high selectivity permeable & has folding = cristae to increase surface area for increase number of proteins in this area to produce maximum ATP molecules. • - Matrix= semi fluid interior filling with enzymes, DNA, ribosome's. • - Most mitochondrial proteins concentrated in cytosol. • - Specific membranes & compartments = mitochondrial functions in table 10. 1. • - Functions of outer membrane: phospholipids synthesis, fatty acid desaturation, fatty acid elongation,

photosynthesis • - Functions of inner membrane: electron transport, oxidative phosphorylation, metabolic transport. • - Functions of matrix: pyrouvate oxidation, TCA cycle, B oxidation of fats, DNA replication, RNA synthesis, protein synthesis. - f f 1 complex ATP synthesis(in plasma membrane of • prokaryotes).