BIO SCI D103 Lecture Notes - Lecture 4: Atp Synthase, Nadh Dehydrogenase, Intermembrane Space
24 Jul 2019
School
Department
Course
Professor
Document Summary
Mitochondria are dynamic and plastic: can remain stationary or move long distances being propelled by microtubular cytoskeleton. Outer membrane is freely permeable to ions and small molecules b/c contains porins: therefore, intermembrane space has same ph and ionic composition as cytoplasm and no electrochemical gradient across the outer membrane. Matrix contains mitochondrial dna and ribosomes, also produces nadh through citric acid cycle. How mitochondria generate atp: electrons go down etc pushing h+ into intermembrane space, h diffuse back into matrix through atp synthase producing atp. Redox potential increases as electrons flow down: nadh dehydrogenase complex ubiquinone cytochrome c reductase complex cytochrome c cytochrome c oxidase complex. Proton motive force created by: ph gradient across inner membrane with high ph in matrix (~8) and lower ph in intermembrane space (=cytosol~7. 4, voltage gradient creating a membrane potential with matrix side negative and crista space positive. Mitochondria critical for buffering redox potential in cytosol.
