BSC 1010C Lecture Notes - Lecture 7: Inner Membrane, Proteobacteria, Chloroplast
Document Summary
*extracts chemical bond energy from food to make atp. *inner membrane has at or tubular projections (cristae) Has its own dna (circular-just like prokaryotic dna) * 1) ancient eukaryote feeds by engul ng other cells. Does not digest; mutually bene cial endosymbiosis is established. * 3) endosymbiotic bacterium evolved into integral part of the cell (mitochondrion, chloroplast) Most endosymbiont genes eventually transformed into nucleus. Engulfed and sustained as endosymbionts within eukaryote cell. Evidence that mitochondria and chloroplasts arose from endosymbiotic bacteria: Plasmodesmata : cytoplasmic interconnections between adjacent cells. Scaffolding of micro laments and microtubules (assembled and disassembled as needed) These provide structure; movement of cells and organelles. Binds to actin, then changes conformation, causing laments to slide past each other. Releases, regains original conformation , binds again - requires atp. Cell movements mediated by micro laments (actin and myosin) Microtubules are hollow & made of tubulin. They provide : trackways for vesicle transport from rrt to golgi.