LIFE 120 Lecture Notes - Lecture 8: Cellular Respiration, Chloroplast, Mitochondrion
Document Summary
4. 5 mitochondria and chloroplasts change energy from one form to another. Mitochondria are the sites of cellular respiration, a metabolic process that uses oxygen to generate atp. Chloroplasts, found in plants and algae, are the sites of photosynthesis. Contain free ribosomes (70s) and circular dna molecules. Grow and reproduce somewhat independently in cells (coordinated with nucleus and cell division) An early ancestor of eukaryotic cells engulfed a nonphotosynthetic prokaryotic cell, which formed an endosymbiont relationship with its host. The host cell and endosymbiont merged into a single organism, a eukaryotic cell with a mitochondrion. At least 1 of these cells may have taken up a photosynthetic prokaryote, becoming the ancestor of cells that contain chloroplasts. They have a smooth outer membrane and an inner membrane folded into cristae. The inner membrane creates 2 compartments: intermembrane space and mitochondrial matrix. Some metabolic steps of cellular respiration are catalyzed in the mitochondrial matrix.
