BIOL 1441 1st Edition Lecture 1 Outline of Last Lecture I. Reviewed syllabusOutline of Current Lecture I. Structure II. Energy III. Chemical propertiesCurrent LectureI. STRUCTURE=FUNTIONa. How does the body work?i. Chemical reactions (rxn’s)1. Chemical reactions: molecules making and breaking bondsb. Atom: smallest unit of matter that still retains the properties of an elementi. Electrons (-)ii. Protons (+)iii. Neutrons (neutral)iv. Protons/neutrons make up nucleusv. Neutral electrical charge unless otherwise indicatedvi. NUMBER OF PROTONS=NUMBER 0F ELECTRONSc. Element: cant be broken down into other substances by chemical rxn’si. Consist of a certain kind of atom that is different from other elementsii. Elements categorized by # of atomsiii. Carbon, oxygen, hydrogen, nitrogen: make up 96% of all living matter1. Phosphorous, sulfur, calcium, potatssium-4%iv. Trace element: required in minute quantities 1. Iron, iodinea. Goiter: iodine deficiencyd. Matter: made up of elementsi. Anything that takes up space and has masse. Compound: substance consisting of 2 or more different elements combined in a fixed ratioThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.f. Atomic mass: weight of nucleus (neutrons and protons); electrons weigh almost nothingi. Dalton (atomic mass unit, amu)1. 1 proton or neutron = 1 daltong. Atomic number: number of protonsi. All atoms of a particular element have the same number of protonsh. Isotopes: same elements but different number of neutronsi. Atomic number stays sameii. Atomic mass will changeiii. Radioactive isotopes: unstable1. Neutrons start decaying2. Gives off particles and energy3. Give off portion which changes elementII. Energy a. Atom’s ability to interact with other molecules chemical rxni. Atoms collide: only electrons interactb. Energy: capacity to cause changei. Kinetic energy: energy of movementii. Potential energy: energy matter possesses due to location or structurec. Low energy=stabled. Electrons have potential energyi. Depends on how electrons are arranged in relation to the nucleusii. THE FURTHER AWAY ELECTRONS ARE FROM THE NUCLEUS=MORE POTENTIAL ENERGYe. Negative electrons attracted to positive protonsf. Matter moves to the lowest possible state of potential energyg. Electrons can have changes in potential energy which occurs in fixed stepsh. Energy level: how much potential energy electrons possessi. Correlates to average distance from nucleusi. Electron shells: energy levelsi. Can moveii. Absorbs energy-moves farther awayiii. Loses energy-moves closerIII. Chemical properties-reactivitya. Chemical behavior is determined by electron configurationb. Chemical behavior depends on the number of electrons in the outermost shell (valent shell)c. Shells:i. 1st shell: 2 electronsii. 2nd shell: 8 electronsiii. 3rd shell: 8 electrons1. Ex. Oxygen a. Shell 1- 2 electronsb. Shell 2- 6 electrons (missing 2 electrons)d. Full valence shell: stable, unreactive, inerte. Incomplete valence shells: unstable, reactive*shells aren’t real, just spacef. Orbital: pathways that electrons circle around nucleusi. Each orbital can hold 2 electronsii. Shell 1- 1s (1 orbital)iii. Shell 2- 2s (1 orbital)- 3p( 3 orbital)-fills up after
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