BIOL 1441 1st Edition Lecture 5 Outline of Last Lecture I. Moderation of temperature (continued)II. Expansion upon freezingIII. Universal solventIV. Section 3: molecular massV. Section 4: pHOutline of Current Lecture I. Carbon II. Carbon diversityIII. Functional groupsCurrent LectureI. Carbon: Backbone of Biological Moleculesa. All living organisms are composed of carbon based moleculesi. Cells 70–95% waterii. 5-30% carbon-based compoundsiii. Proteins, DNA, carbohydrates, lipidsb. Carbon interact with other atoms diverselyi. Form large, complex, different moleculesc. Carbon is source of lifei. Carbon Cycle1. Plants use CO2 + sunlight = starches/sugars2. ENERGY & O2d. Organic Chemistry: Study of carbon compounds i. Any compound containing carbon- organicii. Simplex or complexiii. Contain H atomsThese 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.iv. % of major elements (C, H, O, N, S, P) found in similar proportions between organismsII. Carbon Diversitya. Bonds to 4 other atomsb. Electron configuration determines the kinds and number of bonds an atom will form with other atomsc. Carbon Bondsi. 4 valence electronsii. Forms 4 covalent bonds- tetravalence1. Large, complex molecules possibleiii. Single covalent bond- one electron shared1. Molecules with multiple carbons- each C bonds to 4 other atoms 2. Tetrahedral shape- angles 109.5°iv. 2 carbon atoms joined by a double bond, molecule has a flat shape1. Share 2 electrons- same planev. Electron configuration allows covalent compatibility with many different elements1. Most frequent partners hydrogen, oxygen, nitrogen2. Examplesa. CO2 b. O C Oc. C makes 2 double covalent bondsd. Total of 4 covalent bondse. Urea CO(NH2)2 d. Molecular Diversity- Carbon Skeletoni. Skeletons varyii. Straight, branched, ringsiii. Lengthiv. Double bonds- number, locationv. Change the carbon skeleton, change the shape (structure)e. Hydrocarbonsi. Organic molecules consist of only carbon & hydrogenii. Lipids or fatsiii. Hydrophobic (do they cross cell membranes?)iv. Petroleum - fossil fuelv. Partially decomposed remains of organisms millions of yrs agovi. Hydrocarbons can undergo reactions that release a large amount of energyvii. Body stores fatf. Isomersi. Compounds with same molecular formula but different structures and properties1. Structural2. Geometric3. Enantiomersii. Structural Isomers1. Have different covalent arrangements of their atoms or location ofdouble bond2. C8H8 18 possible structures3. C20H43 366,319 possible structures4. Geometric Isomersa. Have the same covalent arrangements, but differ in spatial arrangementsb. Inflexibility of double bonds5. Enantiomersa. Isomers that are mirror images of each otherb. Asymmetric carbon- attached to 4 different atoms (or groups of atoms)c. Can be arranged in 2 different waysd. One biologically active, other inactive6. Enantiomers & Pharmaceutical Co.a. Not equally effectiveb. L-dopa- Parkinson’s Diseasec. D-dopa not effectived. Harmful- Thalidomide 50-60’se. Mixture of enantiomers- pregnant womeni. Reduced morning sicknessii. Severe birth defectsIII. Functional Group: chemical groups that affect molecular function a. Contribute by affecting molecules shapeb. Directly involved in chemical reactionsc. Each functional group participates in chemical rxn’s in a characteristic wayd. Functional Groups- reactive functional groups hydrophilic: increase solubility of organic compounds in wateri. Hydroxyl group- OH1. Hydrogen atom bonded to oxygen2. Name: alcohols (names usually end in –ol)3. Functional properties:a. Polar: result of the electronegative oxygen atom drawing electrons toward itselfb. Attracts water molecules, helping dissolve organic compoundsii. Carbonyl group1. Carbon double bonded to oxygen2. Names:a. Ketone: carbonyl group is within a carbon skeletonb. Aldehyde: carbonyl group is at the end of the carbon skeleton3. Functional propertiesa. May be structural isomers with different properties. Found in sugarsiii. Carboxyl group-COOH1. Carbonyl group and a hydroxyl group2. Name: carboxylic acids: organic acids3. Functional properties:a. Acidic properties- source of H+b. Covalent bond between O and H so polar that H+ dissociate reversiblyiv. Amino group-NH21. Amine and a carboxylic acid- compounds with both groups are called amino acids2. Name: amines3. Functional properties:a. Acts as a base: can pick up a H+ from the surrounding solutionb. Ionized: charge of 1+ under cellular conditionsv. Sulfhydryl group-SH1. May be written HS-2. Name: thiols 3. Functional propertiesa. 2 sulfhydryl groups can interact to help stabilize protein structurevi. Phosphate group-OPO32-1. Name: organic phosphates2. Functional properties:a. Makes the molecule an anion-negative chargeb. Potential to react with H2O, release energy3. Adenosine triphosphate (ATP)a. Organic phosphate molecule- energy sourceb. Adenosine attached to 3 phosphate groupsvii. Methyl group(not reactive, contributes to function by affecting shape)-CH31. Name: methylated compounds2. Functional properties:a. Affects the expression of genesi. Transcription: copy DNA into RNAii. Translation: “translate” RNA to proteinb. Shape can change