PHYSICS 20E Lecture Notes - Lecture 15: Cellular Respiration, Archean, Hadean
Document Summary
Lecture 15: the origin of life on earth. Molecules involved in a range of cell functions: Transporters that move molecules from cell to cell. Four eons - major divisions of geological time: hadean: 3. 85 - 4. 57 byr ago. Before life: archean: 2. 5 - 385 byr ago. First life: proterozoic: 540 myr - 2. 5 byr ago. First multi-celled life: phanerozoic: < 540 myr ago. Two types of life: prokaryotes: single-celled organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelles, eukaryotes: any organism with cells that contain a nucleus. In some ways a mix of bacteria and archaea properties. Lipids - molecules, make cell membranes among many other functions. Metabolism - sum of chemical reactions that provide energy for life. Endosymbiotic theory: chloroplasts and mitochondria were created from endosymbiosis. Mitochondria - organelles responsible for cellular respiration and energy production. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant.
