MCB 2050 Lecture Notes - Lecture 22: Intermembrane Space, Citric Acid Cycle, Oxidative Phosphorylation

• School: University of Guelph
• Department: Molecular and Cellular Biology
• Course: MCB 2050
• Professor: John Vessey

Document Summary

Outer and inner membranes differ functionally and in their overall protein and lipid composition. Outer membrane: permeable to ions and small molecules, contains porins barrel shaped integral membrane proteins with a large internal channel. Inner membrane: lies adjacent to outer membrane and forms. Folds (cristae) that extend into the organelle"s interior (folds provide increased surface area) Impermeable: intermembrane space = high [h+]; maintains h+ gradient, site of atp synthesis. Matrix: aqueous interior, site of the tca cycle, atp from oxidative phosphorylation, contains mitochondrial genome circular dna, varies between species in size, copy and gene number. In humans: encodes 13 proteins, 2 rrnas and 22 trnas: contains ribosomes used for translation of mitochondrial genome-encoded proteins, all other mitochondrial proteins are nuclear encoded. Rates of fission versus fusion control the number, size and inter- connections of the mitochondrial network ( organelle homeostasis ) Defects in mitochondrial network correlate with the progression of numerous neurodegenerative diseases (eg. alzheimer"s, parkinson"s)