2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P
2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
CHAPTER 19 ORGANIC CHEMISTRY II: POLYMERS AND BIOLOGICAL COMPOUNDS
COMMON FUNCTIONAL GROUPS
19.1 Haloalkanes R–X
◈ Nucleophilic substitution reaction
(친핵치환반응,親核置換反應)
Æ C–X bond is polar
Æ Nucleophile replaces X
– Ex: OH ion (– charge), H2O (lone pair)
Æ Hydrolysis in EtOH(aq) solution
−− CH33Br +⎯OH ⎯→+CH OH Br
19.2 Alcohols R–OH
◆ –OH group, –ol
Ex: CH3OH: methanol (methyl alcohol)
C2H5OH: ethanol (ethyl alcohol)
CH3CH2CH2OH: 1-propanol
CH3CH(OH)CH3: 2-propanol
CH3CH(OH)CH2CH3: Fig. 19.1 The charge distribution in 2-butanol or 2-hydroxybutane an ethanol molecule.
Æ Less volatile than alkanes due to hydrogen bonds:
Ex: ethanol(l) vs. butane(g)
1 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
◆ Classification of alcohols according to the number of organic groups attached to the C atom
connected to the –OH group:
Primary alcohol: RCH2–OH ex: ethanol
Secondary alcohol: R2CH–OH ex: 2-butanol
Tertiary alcohol: R3C–OH ex: 2-methyl-2-propanol, (CH3)3COH
or tertiary-butyl alcohol or tert-butanol
◆ Synthesis of alcohols Æ Nuclear substitution of haloalkanes ▶ Methanol o CO(gg) + 2 H ( ) ⎯catal⎯⎯⎯⎯⎯⎯⎯⎯yst, 250 C,50-100 atm⎯→CH OH(g) 23 synthesis gas
Catalyst: mixture of Cu, ZnO, Cr2O3 ▶ Ethanol • Fermentation of carbohydrates. • Hydration of ethane
o HP34O, 300C CH22=CH (gg) + H2O( ) ⎯⎯⎯⎯⎯⎯→CH3CH2OH
▶ Ethylene glycol 1,2-ethanediol Diol, two –OH groups Antifreeze component Synthetic fiber
1,2-ethanediol, HOCH2CH2OH 19.3 Ethers R – O – R’
CH32CH −−O CH2CH3, diethyl ether Lower boiling points than alcohols due to lack of hydrogen bonds
Fig. 19.2 The lower boiling points of ethers than those of alcohols.
2 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
▶ Crown ethers : cyclic ethers, Pedersen (1960)
18-crown-6
(1,4,7,10,13,16-hexaoxacyclooctadecane)
m–crown–n
m: number of atoms in the cycle 18-crown-6
n: number of O atoms
Strong binding with metal cations
Æ ‘Trojan horse’ for K+ ions
Æ soluble in nonpolar sovents 18-crown-6-K Ex. KMnO4(crown ether)
★ Nobel Laureates in Chemistry (1987)
"for their development and use of molecules with structure-specific interactions of high selectivity"
出生地: 釜山 父: Norwegian marine engineer Steam-ship to far-east (釜山) Worked at Custom service Worked at Unsan mine Donald J. Cram Jean-Marie Lehn (美,1919-2001) (佛,1939 - ) (平北 雲山金鑛, 미국인 채굴권) Charles J. Pedersen (美,1904-1989) 母: Japanese
◆ Phenols
▶ Phenol, C6H5OH or Carbolic acid
Weak acid, but stronger than EtOH
Partial oxidation of benzene, Distillation of coal
Toxic: lethal dosage,1g WWII
Reaction with chlorine in tap water Æ foul smell of C6H5Cl
Contamination of Nakdong river in 1991
3 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
▶ Substituted phenols
Essential oils: concentrated, hydrophobic liquids containing volatile aroma compounds from plants.
Thymol: Oil of thyme
Eugenol: Oil of clove
Distillation of herbal plants
Used for cosmetics, perfumes
– ▶ Resonance structures of phenoxide ion, C6H5O
←⎯→ ←⎯→ ←⎯→
Æ Conjugate base of phenol stabilizes the anion 4 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
– Æ Weaker conjugate base than ethoxide, CH3CH2O
Æ Phenol is insoluble in water
but soluble in basic solution.
☻ Phenyl methanol, C6H5CH2OH: Benzyl alcohol Æ alcohol, not a phenol
19.4 Aldehydes and Ketones
◆ Aldehyde: –al
▶ Formaldehyde, HCHO methanal
600o C, Ag 2 CH32OH(gg) +⎯O ( ) ⎯⎯⎯⎯→+2 HCHO(g) 2 H2O(g)
Destructive effect on bacteria
Wood smoke contains HCHO Æ preservation of smoked foods (훈제,燻製)
“Formalin” : aqueous solution of HCHO Æ preservation of biological specimens
Sick house syndrome (새집증후군,새집症候群)
► Tollens test: ‘Silver mirror’ formation by aldehyde
+ CH32CH CHO(g) + Ag (in Tollens reagent)
⎯⎯→+CH32CH COOH Ag(s) Tollens reagent: ammoniacal silver nitrate
[Ag(NH3)2]NO3 (aq) aldehyde ketone Fig.19.3 The results of Tollens test ▶ Acetaldehyde, CH3CHO ethanal
▶ Aldehydes in essential oils
cherry, almond cinnamon (계피,桂皮) vanilla
5 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
◆ Ketone: –one
▶ Acetone, propanone
Good solvent, miscible with water
Oxidation of secondary alcohol:
CH3CH(OH)CH3(aq) + NaOCl (aq) ⎯⎯→ CH3(CO)CH3 (aq) + NaCl (aq) + H2O (l)
▶ Other ketones:
CH3CH2CH2COCH3, 2-pentanone CH3CH2COCH2CH3, 3-pentanone
☻ No reaction with Tollens reagent
19.6 Carboxylic Acids, R–COOH, -oic acid
▶ Carboxyl group,
◆ Formic acid, HCOOH metanoic acid
◆ Acetic acid, CH3COOH ethanoic acid
▶ Oxidation of primary alcohols and aldehydes with a strong oxidizing agent, acidic KMnO4(aq)
▶ Direct oxidation of alkyl groups to carboxyl group
RC−−O−R' 19.7 Ester, || , -oate O
Æ Product of the reaction between a carboxylic acid and an alcohol
Æ Fragrant odors, flavors of fruits
▶ Ethyl acetate, ethyl ethanoate
6 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
←⎯→
▶ Benzyl acetate, CH3COOCH2C6H5 Å Oil of jasmine
▶ Tristearin, C57H110O6 Å animal fat
Product of the reaction between glycerol and stearic acid, CH3(CH2)16COOH
◆ Condensation reaction
Fig. 19.4 Two molecules are linked in a condensation reaction.
★ Trans fats (트랜스지방脂肪)
► Hydrogenation of oils (ester of cis-unsaturated fatty acids)
Æ saturated fats with higher m. p. : solid, good for baking and extended shelf-life
Æ remaining double bonds converted from cis to trans isomers Å bad for health!
► Transesterification (에스터교환):
Switching of the long carboxylic acid chains from one alcohol location to another in
a fatty acid by an enzyme. Å acid catalyst
Æ double bonds remained with high m.p. but no trans fats
7 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
19.8 Amines, Amino Acids, and Amides | ◆ Amines: R–NH2 (primary), R–NH–R’ (secondary), N (tertiary) / \
ammonia methylamine dimethylamine trimethylamine (primary) (secondary) (tertiary)
► Quaternary ammonium ions: tetrahedral structure
+ Tetramethylammonium ion, (CH3)4N
+ Trimethylammonium ion, (CH3)3NH
► Functional group: amino group, –NH2
► Weakly basic except quaternary ammonium ions
► Foul smell of decaying flesh (along with sulfur compounds)
putrescine, NH2(CH2) 4H2 cadaverine, NH2 (CH2) 5NH2
☻ putrefy : 부패시키다 ☻ cadaver: (해부용)시체(屍體)
◆ Amino Acids NH2 – R – COOH Æ Carboxylic acids containing an amino group (basic) and a carboxyl group (acidic)
▶ Glycine
NH2CH2COOH
α -amino acid
+ – “Zwitterion” in aqueous solution (pH=7): H3NCH2CO2
▶ Alanine
CH3CH(NH2)COOH
α -amino acid
+ + – – NH3CH(CH2)COOH Æ NH2CH(CH2)COOH ( NH3CH(CH2) CO2 ) Æ NH2CH(CH2) CO2
acidic solution neutral solution basic solution
8 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
Fig. 19.5 The fractional composition of alanine species as a function of pH.
γ β α ▶ GABA (gamma-aminobutyric acid): NH22C H C H2C H2COOH
Æ γ -amino acid
Æ One of Neurotransmitters (신경전달물질): GABA, Dopamine, Acetylcholine, …
◆ Amide Æ Condensation product of an amine with a carboxylic acid
R – (CO) – NHR’ from a primary amine
⎯⎯→
▶ Mechanism of amide formation
(1) An amine (base) accepts a proton from a carboxylic acid, forming quaternary ammonium salt.
− + CH33COOH +⎯CH NH2⎯→+CH3CO2CH3NH3
(2) Upon heating to 200oC,
Attacking of amine (nucleophile) to the carboxyl carbon Æ Reverse proton transfer
⎯⎯→ ⎯⎯→ ⎯⎯→
9 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
Caprolactam Nylon-6 Å polyamide
Ex. 19.1 Naming compounds with functional groups
3-methyl-2-butanol 4-chloro-2-pentanone diethylpropylamine
CH3CH(CH3)CH(OH)CH3 CH3CHClCH2COCH3 (CH3CH2) 2NCH2CH2CH3
THE IMPACT ON MATERIALS
◈ Macromolecules
◆ Polymers: chains or networks of small repeating units forming giant molecules
Æ Made by addition reaction and condensation reaction
19.9 Addition Polymerization
◆ Alkenes:
Ex: Ethene (monomer, repeating unit) Æ Polyethylene, – (CH2CH2)n –
◆ Substituted ethene monomer, CHX=CH2
X=Cl : CHCl=CH2, vinyl Æ Polyvinyl chloride (PVC), – (CHClCH2)n –
X=CH3 : CH3CH=CH2, propene Æ Polypropylene, – (CH(CH3)CH2)n –
10 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
◆ Radical polymerization
● Initiation: ● Propagations:
● Termination: no more monomers, linkage of two radical chains
★ Problem ! : Random orientation and side-chain growth of polypropylene Æ Poor packing
▶ Ziegler-Natta catalyst : TiCl4 + (CH3CH2)3Al
Fig. 19.6 Substituents in a polymer with (a) random and (b) stereoregular (with Z-N catalyst) orientations. 11 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19 ★ Nobel Laureate in Chemistry (1963) "for their discoveries in the field of the chemistry and technology of high polymers"
Karl Ziegler Giulio Natta (獨,1898-1973) (伊,1903-1979) ● Ziegler: organoaluminum compound catalyst
Æ control polymerizations and to obtain molecular chains of the required length
● Natta:
Æ a certain Ziegler catalyst leads to a steroregular isotactic polymer Å High-density polymer
Å The floating PE, produced from high pressure polymerization.
Å The bottom one, produced with a Z-N catalyst.
Fig. 19.7 The two samples of polyethylene in a test tube. ▶ Rubber: a polymer of isoprene
Isoprene Fig. 19.8 Collecting latex from a rubber tree.
► Natural rubber: obtained from latex from the bark of rubber tree ► Artificial rubber: obtained with Z-N catalyst Æ cis-polyisoprene Naturally occurring material, “gutta-percha” (a plant’s name in Malay, “getah perca”) Æ trans-polyisoprene (golf ball, filling dental canals)
12 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
Fig. 19.9 (a) Natural rubber (all cis) (b) “Gutta percha” (all trans)
19.10 Condensation Polymerization ◈ Condensation polymers ◆ Polyester: Condensation of monomers with carboxyl group and those with hydroxyl group ▶ Dacron (or Terylene) : polyethylene terephthalate Æ esterification of terephthalic acid with ethylene glycol (1) first step
(2) second step: further condensations a new ethylene glycol Æ carboxyl group of the product another phthalic acid Æ hydroxyl group of the product …………………………………… (3) Final product
☻ Condensation polymerization : growth of chain occurs only at functional groups Æ chain branching less likely ! Æ good synthetic fibers
Fig. 19.10. Synthetic fibers through Fig.19.11 A scanning electron micrograph of a spider’s spinneret (방적돌기,紡績突起) Dacron polyester and cotton fibers.
13 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
◆ Polyamides : Condensation polymerization of amines with carboxylic acids
▶ Nylon-66 : Wallace Carothers (DuPont, 1935)
Æ a polymer of 1,6-diaminohexane, H2N(CH2)6NH2, and adipic acid, HOOC(CH2) 4COOH
(1) Formation of “nylon salt”
– – + + HOOC(CH2) 4COOH + H2N(CH2)6NH2 Æ O2C(CH2) 4CO2 + H3N(CH2)6NH3
(2) Condensation upon heating “nylon salt”
+
⎯⎯→ + H2O
Fig.19.12 A crude nylon fiber. Upper layer: an acid dissolved in hexane Bottom layer: an aniline salt dissolved in water Interface: formation of polymer pulled out in a long string
(3) Further condensation leads to…
Fig. 13 The strength of nylon fibers comes from the hydrogen bonds between neighboring polyamide chains
Ex. 19.2 Determining the formulas of polymers and monomers
Write the formula of (a) the monomer of Kevlar, a strong fiber for bullet-proof vests:
14 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
(b) two repeating units of the polymer that is formed when peroxides are added to
CH3CH2CH=CH2 at high temperature and pressure.
[Solution]
(a) Two amide groups face in opposite directions
Æ Polyamide formed from two different monomers:
One with two acid groups and the other with two amine groups
(b) The monomer is an alkene. Æ forming an addition polymer
Self-Test 19.4A
(a) Write the formula for the monomer of Teflon, – (CF2CF2)n – . CF2=CF2
(b) Write the formula for the polymer of lactic acid, CH2CH(OH)COOH
[Solution] (a) CF2=CF2
(b) – (OCH(CH3)CO)n –, biodegradable polymer, surgical sutures (봉합사,縫合絲)
Self-Test 19.4B
(a) Write the formula for the monomer of Poly(methyl methacrylate), PMMA.
(b) Write the formula for the two repeating units of polyalanine,
the polymer of the amino acid alanine, CH3CH(NH2)COOH
15 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
[Solution] (a) Monomer: CH2=C(CH3)COOCH3 (b) Monomer: CH3CH(NH2)COOH
Polyalanine
19.11 Copolymers and Composites ◆ Copolymers (공중합체,共重合體): Polymers made up of more than one type of repeating units
Fig.19.14 The classification of cop[olymers
▶ Alternating copolymer
Nylon-66: 1,6-diaminohexane, H2N(CH2)6NH2 / adipic acid, HOOC(CH2)4COOH
▶ Block copolymer
Polystyrene: transparent, brittle
Polybutadiene: synthetic rubber, resilient, soft, opaque
● Poly(styrene/butadiene): high-impact polystyrene, strong, transparent
Styrene-butadiene rubber (SBR): tires, shoes, chewing gums
▶ Random copolymer: random linkage of different monomers
► Graft copolymer: Long chain of one monomer with shorter chains of the other monomer
attached as side groups
Hard contact lens: nonpolar hydrocarbon repelling water
Soft contact lens: backbone of nonpolar monomers with side groups of different
water-absorbing monomers (50% volume of lens)
16 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
◆ Composite materials (복합재료) ► Bone tissue: low density, strength Æ Crystals of phosphate salts embedded in fibers of a natural polymer, collagen ► Mollusk (연체동물) shell:
Æ Flat crystals of CaCO3 embedded in a tough, flexible organic matrix.
Fig.19.15. The mollusk shell of the mother-of-pearl. Fig.19.16. A mollusk shell design for an F1 car.
19.12 Physical Properties of Polymers ► Average molar mass, Average chain length ► No definite m.p.
Gradual softening with temperature Æ Glass transition temperature, Tg ► Viscosity of molten polymer ∝ chain length ► Mechanical strength Longer chain length Properties of functional groups Æ Affect the strength of intermolecular forces Chain packing arrangements Unbranched chain polymers are strong ▶ Elasticity Natural rubber: low elasticity “Vulcanization(가황,加黃)” increases elasticity Fig.19.17 The cross-links between polyisoprene chains. Too many cross-linking Æ hard “ebonite”
BOX 19.1 FRONTIERS OF CHEMISTRY: CONDUCTING POLYMERS
★ Nobel Laureates in Chemistry (2000) "for the discovery and development of conductive polymers"
Alan J. Heeger Alan G. MacDiarmid Hideki Shirakawa 변형직(邊衡直)박사 (美,1936 – ) (美/新西蘭,1927-2007) (日,1936 – )
17 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19 ▶ Polyacetylene
Oxidation of polyacetylene with iodine increases
the conductivity by 10 million times. Flexible polyacetylene film
sp2 hybrid C atoms, alternation of double and single bonds
Æ delocalization of electrons along the entire chain
▶ Polypyrrole:
Smart windows: transparent yellow-green
⎯⎯light⎯→ opaque blue-black
Radar camouflage cloth: absorbing microwaves
▶ Polyaniline:
Flexible coaxial cable
Rechargeable, flat, button-like batteries
Laminated, rolled films for TV screens
▶ Poly-p-phenylenevinylene (PPV)
Electroluminescent
Multicolor light-emitting LED
THE IMPACT ON BIOLOGY 19.13 Proteins : Condensation copolymers of ~20 different naturally occurring amino acids
◈ 9 Essential amino acids: to be ingested to our body by diet
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
18 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
◆ Peptide:
Condensation product of two or more amino acids
Peptide bond: –CO–NH–
Residue: each monomer used to form a peptide Ex: Gly-Ala
► Oligopeptide: a few amino acids residues present
Ex: Aspartame: artificial sweetener, dipeptide (with 2 residues)
◈ Structure of proteins
▶ Primary structure: sequence of residues in the protein chain
► Aspartame: Phe-Asp (phenylalanine and aspartic acid)
► Human hemoglobin:
Leu-Ser-Pro-Ala-Asp-Lys-Thr-Asn-Val-Lys-… …-Val-Lys-Gly-Trp-Ala-Ala-…
…-Ser-Thr-Val-Leu-Thr-Ser-Lys-Ser-Lys-Tyr-Arg Fig. 19.18 Sickle-shaped red ☻ Modification of the primary structure Æ congenital desease blood cells due to GluÆVal.
19 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19 ▶ Secondary structure: shape adopted by the polypeptide chain (how it coils or forms sheets) ► α -helix : helical conformation held in place by hydrogen bonds
Fig. 19.19 A representation of an α -helix ► β -sheet: side-by-side arrangement to form nearly flat sheets, ex: silk ► Alternating α -helix and β -sheet:
Fig. 19.20 One of the four polypeptide chains that make up the human hemoglobin molecule. The chains consist of alternating regions of α -helix and β -sheet.
▶ Tertiary structure:
► Folded shape of secondary structure due to interactions between residues (e.g. –S–S– link)
► Globular form of each chain in hemoglobin
► Incorrect folding: Alzheimer’s disease,
“Prion disease” – Mad cow disease (variant Creutzfeld-Jakob disease)
Fig.19.21 Formation of α -helix and β -sheet and folding of coils and sheets to form the shape of protein. (a) Newly formed polypeptide; (b) intermediate; (c) subunit; (d) mature (dimeric) protein.
20 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
▶ Quaternary structure:
► Stacking together of neighboring polypeptide chains in a specific arrangement
► Quaternary structure of four polypeptide chains of hemoglobin
Fig. 19.22 The spider web. Fig. 19.23 The artificial spider silk.
19.14 Carbohydrates (탄수화물,炭水化物)
▶Usual empirical formula, CH2O
▶Sugars (glucose/aldehyde, fructose/ketone)
▶Contain many –OH groups
Æ alcohols, hydrogen bonds
◆ Polysaccharides: Polymers of glucose
▶ Starch
► consists of two components: amylose and amylopectin ► amylase: makes up 20~30% of starch, several thousand glucose units ► amylopectin: branched large structure, million glucose units
Fig. 19.24 The amylase molecule, one component of starch, is a polysaccharide.
21 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
Fig. 19.25 The highly branched large amylopectin molecule
▶ Cellulose : ► the same glucose monomer units but with linked differently ► flat, ribbonlike strands Æ hydrogen bonds
Fig. 19.26 (a) Cellulose, a polysaccharide of glucose units linked together to form long, flat ribbons that can produce a fibrous material through hydrogen bonding. (b) Long tubes of cellulose form the structural material of an aspen tree.
19.15 Nucleic Acids
◈ DNA (Deoxyribonucleic acid)
► Production of protein
► Carry genetic information to the next generation
► Ribose
Fig. 19.27 A DNA molecule (~2m) spilled out of a damaged cell of a bacterium.
22 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19 ▶ Deoxyribose
▶ Bases (amines): A, G, C, and T (DNA) or U(RNA)
▶ Nucleoside: sugar (deoxyribose) + base attached to C1
▶ Nucleotide: sugar (deoxyribose) + base attached to C1 + phosphate at C5
23 2009년도 제2학기 화 학 2 담당교수: 신국조 Textbook: P. Atkins / L. Jones, Chemical Principles, 4th ed., Freeman (2008) Chapter 19
▶ Nucleic acid : Product of condensation of nucleotides
Fig. 19.28 The condensation of nucleotides leading to the formation of a nucleic acid.
◈ Double helical structure of DNA: hydrogen bonds between A=T and G≡C
Fig. 19.29 The base pairings by hydrogen bonds(A=T and G≡C) leads to double helical structure of DNA.
24