BIOL 1202 : Exam 2 Material
Document Summary
Chapter 25: the history of life on earth. The earth is very old: about 4. 6 billion years old, as earth cooled the oceans formed. The building blocks of macromolecules can be formed from nonliving matter if the conditions are right. Build amino acids to get proteins, etc: chemical and physical processes on early earth, aided by emerging force of natural selection, could have produced cells through a sequence of four stages, 1. Abiotic (nonliving) synthesis of small organic molecules, such as amino acids and nitrogenous bases: 2. Joining of small molecules into macromolecules like proteins and nucleic acids: 3. Packaging of these molecules into protocells, droplets with membranes that maintained an internal chemistry different from that of their surroundings: 4. The origin of self-replicating molecules that eventually made inheritance possible. Haldane in england: aleksandr i. oparin, a russian biochemist, Independently hypothesized that the atmosphere of the primitive earth was probably very different from today"s.
