Medical Chemistry & Biochemistry Lectures PDF

MEDICAL CHEMISTRY AND BIOCHEMISTRY FACULTY OF DENTAL MEDICINE DR. AKSU SAMET INTRODUCTION TO BIOCHEMISTRY  BIOCHEMISTRY WHAT IS BIOCHEMISTRY? BIOCHEMISTRY IS THE STUDY OF THE CHEMISTRY OF LIVING THINGS. THIS INCLUDES ORGANIC MOLECULES AND THEIR CHEMICAL RE...

MEDICAL CHEMISTRY AND BIOCHEMISTRY FACULTY OF DENTAL MEDICINE DR. AKSU SAMET INTRODUCTION TO BIOCHEMISTRY  BIOCHEMISTRY WHAT IS BIOCHEMISTRY? BIOCHEMISTRY IS THE STUDY OF THE CHEMISTRY OF LIVING THINGS. THIS INCLUDES ORGANIC MOLECULES AND THEIR CHEMICAL REACTIONS. MOST PEOPLE CONSIDER BIOCHEMISTRY TO BE SYNONYMOUS WITH MOLECULAR BIOLOGY.  THE PRINCIPAL TYPES OF BIOLOGICAL MOLECULES OR BIOMOLECULES ARE: CARBOHYDRATES LIPIDS PROTEINS NUCLEIC ACIDS VITAMINS HORMONES  BIOCHEMISTRY IS CLOSELY RELATED TO OTHER BIOLOGICAL SCIENCES THAT DEAL WITH MOLECULES. THERE IS CONSIDERABLE OVERLAP BETWEEN THESE DISCIPLINES: MOLECULAR GENETICS PHARMACOLOGY MOLECULAR BIOLOGY CHEMICAL BIOLOGY CARBOHYDRATES  CARBOHYDRATES LITERALLY MEAN HYDRATES OF CARBON. CARBON AND HYDRATES ( WATER). BECAUSE IT WAS THOUGHT TO HAVE THE MOLECULAR FORMULA (CH2O)N, THE RATIO OF H TO O AS IN WATER (H2O) HENCE THE NAME.  OCCURRENCE AND FUNCTIONS OF CARBOHYDRATES ALMOST 75% OF DRY PLANT MATERIAL IS PRODUCED BY PHOTOSYNTHESIS. MOST OF THE MATTER IN PLANTS, EXCEPT WATER, ARE CARBOHYDRATE MATERIAL. EXAMPLES OF CARBOHYDRATES ARE: CELLULOSE- WHICH ARE STRUCTURAL COMPONENT OF THE PLANTS, STARCH -THE ENERGY RESERVOIR IN PLANTS AND GLYCOGEN (ANIMAL STARCH) FOUND IN ANIMAL TISSUES AND HUMAN BODY IN SMALLER QUANTITIES.  USEFULNESS OF CARBOHYDRATES IS THEIR ABILITY TO PRODUCE ENERGY WHEN THEY UNDER GO OXYDATION DURING RESPIRATION. STORAGE CARBOHYDRATE, IN THE FORM OF GLYCOGEN, PROVIDES A SHORT-TERM ENERGY RESERVE FOR BODILY FUNCTIONS. CARBOHYDRATES SUPPLY CARBON ATOMS FOR THE SYNTHESIS OF OTHER BIOCHEMICAL SUBSTANCES (PROTEINS, LIPIDS, AND NUCLEIC ACIDS). CARBOHYDRATES ALSO FORM A PART OF THE STRUCTURAL FRAMEWORK OF DNA AND RNA MOLECULES. CLASSIFICATION OF CARBOHYDRATES  ORGANIC COMPOUNDS CONTAINING MANY -OH GROUPS (POLYHYDROXY), AND ALDEHYDES OR KETONES FUNCTIONAL GROUPS. BY CONVENTION, THE ENDING "-OSE" IS RESERVED FOR SUGARS (E.G. SUCROSE AND GLUCOSE) IN THE CLASS OF CARBOHYDRATES. CARBOHYDRATES ARE PRODUCED BY THE PROCESS OF PHOTOSYNTHESIS IN WHICH SIX CARBON SUGARS OR HEXOSES ARE PRODUCED USING ENERGY OF SUNLIGHT, GREEN PIGMENT CHLOROPHYLL, CO2 AND H2O BY GREEN PLANTS. THE HEXOSES PRODUCED ARE THE RAW MATERIAL FOR THE BIOSYNTHESIS OF GLYCOGEN, FATS, PROTEINS AND NUCLEIC ACID IN LIVING SYSTEMS. SIMPLER FORMULA FOR CABOHYDRATES: CNH2NON OR CN(H2O)N (HYDRATES OF C) N= NUMBER OF ATOMS MONOSACCHARIDES  MONOSACCHARIDES THEY CONSIST OF ONE SUGAR CONTAINING 3,4,5,6 AND 7 CARBON ATOMS AND ARE USUALLY COLORLESS, WATER-SOLUBLE, CRYSTALLINE SOLIDS. SOME MONOSACCHARIDES HAVE A SWEET TASTE. EXAMPLES-GLUCOSE (DEXTROSE), FRUCTOSE (LEVULOSE), GALACTOSE, XYLOSE AND RIBOSE.  MONOSACCHARIDES ARE CLASSIFIED BY: 1- THE NUMBER OF CARBON ATOMS: 3C-TRIOSE , 4C -TETROSES , 5C-PENTOSES , 6C- HEXOSES AND 7C – HEPTOSES.  2-the position or type of carbonyl group: Aldehyde, aldose (terminal) Ketone, ketose (middle ). 3- Both number of carbon atom and type of carbonyl group Aldotriose and Ketotriose Aldose sugars H C O H C O H C O H C O H C O (H C OH)n H C OH H C OH H C OH H C OH CH2OH CH2OH H C OH H C OH H C OH Aldose Aldotriose CH2OH H C OH H C OH n=1 Aldotetrose CH2OH n=2 H C OH Aldopentose CH2OH n=3 Aldohexose n=4  KETOSE SUGARS CH2OH CH2OH CH2OH CH2OH C O C O CH2OH C O C O (H C OH)n H C OH C O H C OH CH2OH CH2OH H C OH H C OH CH2OH CH2OH H OH Ketose Ketotriose Ketotetrose n=1 Ketopentose H C OH n=0 n=2 CH2OH Ketohexose n=3  IMPORTANT MEMBERS OF MONOSACCHARIDES ALDOSES: MONOSACCHARIDES WITH ONE ALDEHYDE GROUP KETOSES: MONOSACCHARIDES WITH ONE KETONE GROUP ALDOHEXOSE: MONOSACCHARIDE WITH ALDEHYDE GROUP AND 6 C ATOMS – D-GLUCOSE KETOHEXOSE: MONOSACCHARIDE WITH KETO GROUP AND 6 C ATOMS – D- FRUCTOSE  GLUCOSE GLUCOSE IS THE MOST COMMON MONOSACCHARIDE CONSUMED AND IS THE CIRCULATING SUGAR OF THE BLOODSTREAM. INSULIN AND GLUCAGON REGULATE BLOOD LEVELS OF GLUCOSE 1. MOST ABUNDANT IN NATURE 2. NUTRITIONALLY MOST IMPORTANT 3. GRAPE FRUIT GOOD SOURCE OF GLUCOSE (20 - 30% BY MASS) -- ALSO NAMED GRAPE SUGAR, DEXTROSE AND BLOOD SUGAR (70 - 100 MG/100 ML OF BLOOD) 4. SIX MEMBERED CYCLIC FORM  FRUCTOSE FRUCTOSE IS SLIGHTLY SWEETER THAN GLUCOSE. IT IS AN INTERMEDIARY IN METABOLISM AND IS FOUND IN MANY FRUITS. 1. KETOHEXOSE 2. SWEETEST TASTING OF ALL SUGARS 3. FOUND IN MANY FRUITS AND IN HONEY 4. GOOD DIETARY SUGAR-- DUE TO HIGHER SWEETNESS 5. FIVE MEMBERED CYCLIC FORM  GALACTOSE GALACTOSE, A COMPONENT OF LACTOSE (MILK SUGAR) IS ALSO FOUND IN SOME PLANT GUMS AND PECTINS. 1. MILK SUGAR 2. SYNTHESIZE IN HUMAN 3. ALSO CALLED BRAIN SUGAR-- PART OF BRAIN AND NERVE TISSUE 4. USED TO DIFFERENTIATE BETWEEN BLOOD TYPES 5. SIX MEMBERED CYCLIC FORM  RIBOSE RIBOSE AND DEOXYRIBOSE ARE ALDOPENTOSE COMPONENTS OF DNA AND RNA 1. PART OF RNA 2. PART OF ATP 3. PART OF DNA 4. FIVE MEMBERED CYCLIC FORM  DERIVATE OF MONOSACCHARIDES AMINO SUGAR (OR MORE TECHNICALLY A 2-AMINO-2-DEOXYSUGAR) IS A SUGAR MOLECULE IN WHICH A HYDROXYL GROUP HAS BEEN REPLACED WITH AN AMINE GROUP. D-GLUKOZAMIN  URONIC ACIDS- ARE A CLASS OF SUGAR ACIDS WITH BOTH CARBONYL AND CARBOXYLIC ACID FUNCTIONAL GROUPS THEY ARE SUGARS IN WHICH THE TERMINAL CARBON'S HYDROXYL GROUP HAS BEEN OXIDIZED TO A CARBOXYLIC ACID Β-D FORM OF GLUCURONIC ACID.  GLUCOSIDES MONOSACCHARAIDES WITH SEMI ACETAL GROUP CAN BE REACTED BY HYDROXYL GROUPS OF OTHER COMPOUNDS, AS A RESULTS ARE PRODUCING GLUCOSIDES A-D – GLUKOPIRANOZID STEREOISOMERISM  STEREOISOMERISM STEREOISOMERS ARE ISOMERS THAT HAVE THE SAME MOLECULAR AND STRUCTURAL FORMULAS BUT DIFFER IN THE ORIENTATION OF ATOMS IN SPACE. TWO TYPES: ENANTIOMERS ARE STEREOISOMERS WHOSE MOLECULES ARE NONSUPERIMPOSABLE MIRROR IMAGES OF EACH OTHER. MOLECULES WITH CHIRAL CENTER. DIASTEREOMERS ARE STEREOISOMERS WHOSE MOLECULES ARE NOT MIRROR IMAGES OF EACH OTHER. THEY HAVE MORE THAN ONE CHIRAL CENTERS.  FORMS OF ISOMERISM MONOSACCHARIDES EXHIBIT VARIOUS FORMS OF ISOMERISM: BECAUSE IT HAVE ASYMMETRIC CARBON ATOM D AND L ENANTIOMERS. PYRANOSE AND FURANOSE RING STRUCTURES. ALPHA AND BETA ANOMERS. EPIMERS. ALDOSE AND KETOSE ISOMERISM. OPTICAL ACTIVITY  L AND D ENANTIOMERS IT ALSO CALLED MIRROR IMAGES OR OPTICAL ISOMERS: 2-PYRANOSE AND FURANOSE 3 - ALFA - AND ΒETA ANOMERS ISOMERS THAT DIFFER ON THE POSITION OF OH GROUP AROUND ANOMERIC CARBON (WHICH WAS CARBONYL CARBON) WHEN THE RING IS FORMED.  3-EPIMERS (ISOMERS) TWO MONOSACCHARIDE THAT DIFFER FROM EACH OTHER BY POSITION OF OH GROUP ON ONE CARBON. GLUCOSE AND GLACTOSE AR EPIMERS AT CARBON 4WHILE GLUCOSE AND MANNOSE ARE CARBON 2 EPIMERS. Mannose Glucose Galactose 5-ALDOSE AND KETOSE ISOMERISM  OPTICAL ACTIVITY THE ABILITY TO ROTATE PLANE-POLARIZED LIGHT TO THE RIGHT (DEXTROROTATORY) +SIGN DEXTROROTATORY - ROTATE CLOCKWISE SHOWN USING (+) SYMBOL OR - USUALLY D ISOMERS LEVOROTATORY - ROTATE ANTI-CLOCKWISE SHOWN USING (-) SYMBOL OR - USUALLY L ISOMERS CYCLIC FORMS OF CARBOHYDRATES CYCLIC FORMS OF CARBOHYDRATES  CYCLIC FISCHER Haworth Projection PROJECTION OF A-D- of a-D-Glucose GLUCOSE CHEMICAL REACTIONS OF CARBOHYDRATES  CHEMICAL REACTIONS OF CARBOHYDRATES 1. OXIDATION OF CARBOHYDRATES 2. REDUCTION OF CARBOHYDRATES 3. GLYCOSIDES OF CARBOHYDRATES  OXIDATION OF MONOSACCHARIDES. C1 OF ALDOSES CAN BE SELECTIVELY OXIDIZED TO THE CARBOXYLIC ACID (ALDONIC ACIDS) WITH BR2 OR AG(I) (TOLLEN’S TEST).  OXIDATION OF ALDOSES TO ALDARIC ACIDS WITH HNO3.  URONIC ACID: CARBOHYDRATE IN WHICH ONLY THE TERMINAL -CH2OH IS OXIDIZED TO A CARBOXYLIC ACID.  REDUCTION OF MONOSACCHARIDES. C1 OF ALDOSES ARE REDUCED WITH SODIUM BOROHYDRIDE TO THE 1° ALCOHOL (ALDITOLS)  GLYCOSIDE FORMATION ACETAL DERIVATIVES FORMED WHEN A MONOSACCHARIDE REACTS WITH AN ALCOHOL IN THE PRESENCE OF AN ACID CATALYST ARE CALLED GLYCOSIDES. OLIGOSACCHARIDES  OLIGOSACCHARIDES OLIGOSACCHARIDES ARE SHORT POLYMERS CONTAINING 2-10 MONOSACCHARIDE RESIDUES. THE RESIDUES ARE BONDED TO EACH OTHER BY GLYCOSIDIC BONDS. – A GLYCOSIDIC BOND IS THE ETHER LINKAGE FORMED WHEN AN ACETAL IS MADE BY REACTING A HEMIACETAL OF A MONOSACCHARIDE WITH A HYDROXYL ON ANOTHER SUGAR.  MALTOSE GLUCOSE + GLUCOSE --- ALFA(1---4) MALTOSE, A REDUCING SUGAR  LACTOSE GALACTOSE + GLUCOSE --- GAL (1---4) GLU LACTOSE, A REDUCING SUGAR  SUCROSE GLUCOSE + FRUCTOSE --- GLU , (1---2) FRUCTOSE SUCROSE, A NON REDUCING SUGAR POLYSACCHARIDES  POLYSACCHARIDES POLYSACCHARIDES CONTAIN 10 OR MORE RESIDUES – THE RESIDUES ARE BUILT FROM MORE THAN ONE TYPE OF MONOSACCHARIDE – THE PRIMARY FUNCTIONS OF POLYSACCHARIDES ARE TO: - PROVIDE STRUCTURE (E.G. CELLULOSE) - STORE ENERGY (E.G. STARCH AND GLYCOGEN)  STARCH STARCHES ARE CARBOHYDRATES IN WHICH 300 TO 1000 GLUCOSE UNITS JOIN TOGETHER. IT IS A POLYSACCHARIDE WHICH PLANTS USE TO STORE ENERGY FOR LATER USE. STARCH FORMS IN GRAINS WITH AN INSOLUBLE OUTER LAYER WHICH REMAIN IN THE CELL WHERE IT IS FORMED UNTIL THE ENERGY IS NEEDED. THEN IT CAN BE BROKEN DOWN INTO SOLUBLE GLUCOSE UNITS. STARCHES ARE SMALLER THAN CELLULOSE UNITS, AND CAN BE MORE READILY USED FOR ENERGY. FOODS SUCH AS POTATOES, RICE, CORN AND WHEAT CONTAIN STARCH GRANULES WHICH ARE IMPORTANT ENERGY SOURCES FOR HUMANS. THE HUMAN DIGESTIVE PROCESS BREAKS DOWN THE STARCHES INTO GLUCOSE UNITS WITH THE AID OF ENZYMES, AND THOSE GLUCOSE MOLECULES CAN CIRCULATE IN THE BLOOD STREAM AS AN ENERGY SOURCE.  – CELLULOSE IS CONSISTING OF LONG, LINEAR CHAINS OF GLUCOSE RESIDUES JOINED WOOD IS ABOUT 50% CELLULOSE BACTERIA IN HORSES, COWS, AND TERMITES HAVE ENZYME CELLULASE TO HYDROLYZE Β-(1-4) BONDS Cotton fibres represent the purest natural form of cellulose, containing more than 90% of this polysaccharide.  GLYCOGEN IS A MULTI BRANCHED POLYSACCHARIDE OF GLUCOSE THAT SERVES AS A FORM OF ENERGY STORAGE IN ANIMALS, FUNGI, AND BACTERIA. GLYCOGEN IS A BRANCHED BIOPOLYMER CONSISTING OF OF APPROXIMATELY 8–12 GLUCOSE UNITS. GLUCOSE UNITS ARE LINKED TOGETHER LINEARLY BY Α(1→4) GLYCOSIDIC BONDS 1,4-α-glycosidic linkages in the glycogen oligomer METABOLISM OF GLUCOSE  ADENOSINE 5′-TRIPHOSPHATE, ABBREVIATED ATP AND USUALLY EXPRESSED WITHOUT THE 5′-, IS AN IMPORTANT “ENERGY MOLECULE” FOUND IN ALL LIFE FORMS. SPECIFICALLY, IT IS A COENZYME THAT WORKS WITH ENZYMES SUCH AS ATP TRIPHOSPHATASE TO TRANSFER ENERGY TO CELLS BY RELEASING ITS PHOSPHATE GROUPS. NADPH (NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE) IS A REQUIRED COFACTOR FOR CYP-MEDIATED BIOTRANSFORMATION, AND OXYGEN SERVES AS A SUBSTRATE. NADH STANDS FOR "NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD) + HYDROGEN (H)." IT OCCURS NATURALLY IN THE BODY AND PLAYS A ROLE IN GENERATING ENERGY. FLAVIN ADENINE DINUCLEOTIDE, OR FADH2, IS A REDOX COFACTOR THAT IS CREATED DURING THE KREBS CYCLE AND UTILIZED DURING THE LAST PART OF RESPIRATION, THE ELECTRON TRANSPORT CHAIN. ADENOSINE DIPHOSPHATE (ADP), ALSO KNOWN AS ADENOSINE PYROPHOSPHATE (APP), IS AN IMPORTANT ORGANIC COMPOUND IN METABOLISM AND IS ESSENTIAL TO THE FLOW OF ENERGY IN LIVING CELLS.  ADENOSINE 5′-TRIPHOSPHATE, ABBREVIATED ATP AND USUALLY EXPRESSED WITHOUT THE 5′-, IS AN IMPORTANT “ENERGY MOLECULE” FOUND IN ALL LIFE FORMS. SPECIFICALLY, IT IS A COENZYME THAT WORKS WITH ENZYMES SUCH AS ATP TRIPHOSPHATASE TO TRANSFER ENERGY TO CELLS BY RELEASING ITS PHOSPHATE GROUPS. NADPH (NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE) IS A REQUIRED COFACTOR FOR CYP-MEDIATED BIOTRANSFORMATION, AND OXYGEN SERVES AS A SUBSTRATE. NADH STANDS FOR "NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD) + HYDROGEN (H)." IT OCCURS NATURALLY IN THE BODY AND PLAYS A ROLE IN GENERATING ENERGY. FLAVIN ADENINE DINUCLEOTIDE, OR FADH2, IS A REDOX COFACTOR THAT IS CREATED DURING THE KREBS CYCLE AND UTILIZED DURING THE LAST PART OF RESPIRATION, THE ELECTRON TRANSPORT CHAIN. ADENOSINE DIPHOSPHATE (ADP), ALSO KNOWN AS ADENOSINE PYROPHOSPHATE (APP), IS AN IMPORTANT ORGANIC COMPOUND IN METABOLISM AND IS ESSENTIAL TO THE FLOW OF ENERGY IN LIVING CELLS.  HTTPS://WWW.YOUTUBE.COM/WATCH?V=VZAJOPZUIP4