BIO 202 Study Guide - Midterm Guide: Chemical Polarity, Alpha Helix, Endoplasmic Reticulum
15 Jan 2017
School
Department
Course
Professor
Document Summary
Hydrogen, carbon, nitrogen and oxygen make up majority of matter found in organism (chon) Atomic forms of the same element with different number of neutrons. Nuclei of some isotopes are unstable they break down (decay), releasing energy and matter (radioactivity) Unstable isotopes release energy to become stable = radioactive decay. Radioactive elements have specified and constant periods of decay = half life. Tracers = have short have lives = metabolic labelling of biological molecules (dna, protein, etc) A stable orbital contains 2 electrons (one pair) The chemical behavior of atoms depends on its electron configuration. Atoms that are unpaired look for electrons by creating covalent bonds. Carbon, hydrogen, nitrogen, oxygen (most abundant elements) Number of valence electrons = main group # (column) Responsible for the large molecular diversity observed in biology. Non polar = electrons are at equal distances from nuclei. Polar = electrons are shifted toward the nucleus of the more electronegative ato(cid:373) (cid:894)ato(cid:373)"s attra(cid:272)tio(cid:374)(cid:895)
