BIOL 112 Lecture Notes - Lecture 9: Myosin, Carbon Fixation, Endomembrane System

• School: McGill University
• Department: Biology
• Course: BIOL 112
• Professor: Frieder Schoeck

Document Summary

Endosymbiotic organelles with inner and outer membranes. Descendants of bacteria once taken up by ancestral eukaryotic cell through phagocytosis. Independent genome similar to bacterial genes in composition. Unique system for protein and lipid transport suggesting separate evolution from endomembrane system. Mitochondria : power plants of the cell. Citric acid cycle occurs in matrix (space enclosed by inner membrane), also location of dna, rna and ribosomes. Respiratory enzymes located in invaginations of inner membrane(cristae, maximize surface area) Chloroplasts : convert light e to chemical e in photosynthesis. Space enclosed by inner membrane= stroma , also site of dna/rna, ribosomes. Carbon fixation occurs in stroma, yielding all sugars, amino acids and fatty acids. Light reactions take place in s tacks of membranes called thylakoids , separated from inner membrane. Consists of structural elements important for cell shape and movement. Actin filaments are polar, polymerize and depolymerize from monomers through non-covalent protein-protein interactions (monomer= single actin protein).