BIOL 101 Lecture Notes - Lecture 17: Covalent Bond, Surface Tension, Newborn Screening
Document Summary
Crispr: new technique to modify genomes, modify pigs to make better organs suited for human transplants. Miller urey experiment 1953 => tested darwinian theory: central question: how could have life emerged, tried to mimic early earth. Combination of water, methane, ammonia, hydrogen gas. Amino acids and precursor molecules produced less than a week: would have produced many complex, organic molecules, proved that life could just (cid:862)exist(cid:863) rather than putting. We are 93% carbon, hydrogen and oxygen: c (4), h (1), o (2) Atoms contain 3 stable particles: the number of protons determines which element it is (= atomic number) Electrons orbit the nucleus in specific places: the electrons occupy shells around the nucleus, inner shell is filled first. Elements have predictable properties: the periodic table is set up according to the number of electrons in the outermost shell. Covalent bonds: shared electrons between two atoms: covalent bonds are strong, allow atoms to combine into complex, stable molecules.
