BLG 144 Lecture Notes - Light-Dependent Reactions, Light-Independent Reactions, Electrochemical Gradient
Document Summary
All chemical reactions in a cell arranged into metabolic pathways. Anabolic reactions (e. g. photosynthesis) use up energy. Large leaf surface area captures more light. Thin leaves few cell layer more light captured by chlorophyll. Leaf mosaic increases leaf exposure to light. Internal structure: cuctile reduces h2o loss by evaporation, palisade mesophyll chloroplast can move around cell for max light absorption, spongy mesophyll allows diffusion of gases through leaves, phloem sieve tube removes products of photosynthesis. Thylakoid membrane: light-dependent large surface area: associated with chlorophyll, accessory pigments, etc, enzymes. Grana: stacks of thylakoid membranes: enclose hydrogen reservoir used in chemiosmosis. Lamella: tubular extensions forming a network between grana. Stroma: rubp carboxylase catalyses light independent reaction. Starch granule insoluble storage carbohydrate product of photosynthesis. Used to pump h+ from stroma into thylakoid space. H+ conc in thylakoid space > stroma. H+ ions pass back from space between two mitochondrial membranes. Through pores which are associated with the enzyme atp synthetase.
