BIOL 111 Study Guide - Midterm Guide: Hydrogen Bond, Unified Atomic Mass Unit, Endorphins
Document Summary
Chemistry: science that studies the behavior of matter (solid stuff the universe is made up of) Elements are the simplest form of matter. Only about 25 are important to biologists. Elements are defined by its chemical properties (number of protons and electrons) Protons and electrons are always the same, neutrons can vary. Located in nucleus: neutron: about 1 dalton (no charge, proton: mass: about 1 dalton (positive charge, electron: 1/2000 dalton (negative charge) Anything we call an atom will have the same number of electrons and protons: electron shells. 3 electron shells to focus on in biology. Closer to nucleus means lowest in energy. Atom as a whole is neutral, parts are not. 3d volumes occupied by electrons are called orbitals. Ex: hydrogen (not full) highly reactive, helium, full not highly reactive. Charges are opposite making it neutral as a whole, but its subatomic particles are not neutral. Have been used to unravel complex biochemical pathways.