BIOL 1140 1st Edition Lecture 4 Outline of Last Lecture I. Structure of Elements Continueda. Atomic Mass b. Isotopesc. Ionsd. Electron Shellse. Covalent Bondsf. Ionic BondsOutline of Current Lecture I. Hydrogen BondsII. Water and LifeIII. CarbonIV. 4 Classifications of Organic MoleculesV. MacromoleculesVI. LipidsVII. TriglyceridesVIII. PhospholipidsCurrent LectureI. Hydrogen Bondsa. Form between polar moleculesb. Polar molecules...i. Contain polar covalent bonds in which electrons are shared unequallyii. Part of the molecule has partial positive OR partial negative chargec. Weak attraction between oppositely charged regions of polar moleculesd. Example: weak forces between water molecules II. Water and LifeThese 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.a. Water…i. Molecules are polarii. Is liquid at body tempiii. Can absorb and hold heat energyb. Water is a good solvent for other moleculesi. Solvent: liquid in with other substances dissolveii. Solute: any dissolved substance c. Hydrophilic: Polar molecules or ions are attracted to water and interact easily, aka will dissolve in wateri. Remember, Ions = charged atomsd. Hydrophobic: Nonpolar/neutral molecules do not interact with water and therefore cannot dissolve in waterIII. Carbona. Building block of living thingsb. 18% of body by weight i. .03% of earth’s crustc. Forms four covalent bondsd. Can form single or double bondse. Can build micro/macro molecules IV. 4 Classes of organic moleculesa. Carbohydratesb. Lipidsc. Proteinsd. Nucleic Acidse. Also critically important - ATPV. Macromoleculesa. Are synthesized and broken down within the cellb. Made of chains of small subunits that are held together by chemical bonds c. Dehydration Synthesisi. Builds macromolecules from smaller subunitsii. Removes equivalent of a water molecule to link molecular subunits iii. Requires energyd. Hydrolysisi. Breaks apart a macromolecule into its subunits ii. Adds the equivalent of a water molecule to break apart macromolecules iii. Releases energy VI. Carbohydratesa. Macromolecules made of monosaccharide subunits b. General formula: Cn(H20)nc. Examples of monosaccharides: glucose, fructose, galactose, ribose, deoxyribosei. Can be linked together via dehydration synthesisii. Disaccharides- two monosaccharides linked togetheriii. Polysaccharides (complex carbs) - thousands of monosaccharides joined in chains and branchesd. Starch - made in plants, stores energye. Glycogen - made in animals, stores energy f. Cellulose - indigestible polysaccharide made in plants for structural supportg. Chitin - found in the exoskeletons of insects and crustaceans for structural supportVII. Lipidsa. Composed mostly of carbons and hydrogens i. Carbon and hydrogen form nonpolar covalent bondsii. Lipids are mostly nonpolar and hydrophobicb. 3 important classes of lipidsi. Triglycerides1. Energy storage moleculesii. Phospholipids1. Cell membrane structureiii. Steroids1. Many important hormones are steroids (estrogen and testosterone) c. Triglyceridesi. Also known as fats and oilsii. Compose of glycerol and 3 fatty acids1. Fatty acids are long chains of carbons and hydrogensa. Saturated (in fats) - has only single covalent bonds, solid at room temperatured. Phospholipidsi. Structure… glycerol + two fatty acids + phosphate