BIL 150 Lecture Notes - Lecture 2: Glycosidic Bond, Unsaturated Fat, Covalent Bond

• School: University of Miami
• Department: Biology
• Course: BIL 150
• Professor: Diresta Dan

Document Summary

25 of 92 elements essential to life: c, h, o, n = 96% living matter. Trace elements= need small amounts to be cofactors in chemical processes such a copper and chromium. Isotopes= two atoms of an element different # neutrons. Radioactive isotopes used to image in pet scans and trace the molecules path. Stable isotopes used in food webs to determine whether food sources are okay and stable. Valence e- are the ones in the outermost valence shell (2, 8, 8) Based on electronegativity: nonpolar covalent= atoms share e- equally, polar covalent= one more electronegative so don"t share e- equally. Ionic bonds are e- lost or gain because of large difference in electronegativity: forms cations and anions. Hydrogen and ionic bonds= weak chemical bonds: weak bonds reinforce shapes of large molecules. Hydrogen bonds weak: when hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative molecule. Usually oxygen or nitrogen in living things: in dna.