Carbohydrates Structure & Functions Lecture Notes PDF

FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Carbohydrates...

FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Carbohydrates Structure & Functions Lec Module 3 Far Eastern University IAS – Dept. of Mathematics Biochemistry Cluster 1 Outline Introduction to Carbohydrates Carbohydrate Derivatives Amino Sugars Classification of Carbohydrates Aldoses and Ketoses Biologically Relevant Nomenclature of Carbohydrates Monosaccharides Monosaccharides Disaccharides Structure Drawing Oligosaccharides Chirality Polysaccharides Fischer Projection L-and D- Monosaccharides Haworth Projections Chair Conformation 2 1 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Introduction to Carbohydrates Most abundant organic compounds. Act as storehouses of chemical energy. Supportive components in plants. Essential components of nucleic acids “Hydrate of Carbon” 3 Introduction to Carbohydrates “Hydrate of Carbon” Glyceraldehyde Dihydroxyacetone 4 2 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Classification of Carbohydrates ALDOSES ALDOSES 5 Classification of Carbohydrates KETOSES 6 3 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Classification of Carbohydrates A polyhydroxyaldehyde or polyhydroxyketone, or a substance that gives these compounds on hydrolysis. Classifications: 1. Monosaccharides 2. Disaccharides 3. Oligosaccharides 4. Polysaccharides 7 Monosaccharides v Carbohydrates that cannot be hydrolyzed to a simpler compound. v General formula: CnH2nOn v One of the Carbons being the carbonyl group of either an Aldehyde or Ketone. v Suffix “ose” indicates that a molecule is a carbohydrate. 8 4 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Monosaccharides Physical Properties Monosaccharides are colorless, crystalline solids. Water soluble Slightly soluble to Ethanol and insoluble to nonpolar solvents such as diethyl ether, dichloromethane and benzene. 9 Nomenclature of Monosaccharides Aldoses: Monosaccharides containing the aldehyde group (-CHO). Ketoses: Containing the ketone group (-C=O). Prefixes: “tri-, tetr-, pent-” indicates the number of Carbon atoms in the chain. 10 5 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Monosaccharides 11 Structure Drawing 12 6 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chirality: Handedness in Molecules Superimposable mirror images are images that coincide at all points when the images are laid upon each other. Review Nonsuperimposable mirror images are images where not all points coincide when the A person’s left and right hands are not superimposable upon each other. images are laid upon each other. 13 Chirality Examples of simple molecules that are chiral. (a) The mirror image forms of the molecule bromochloroiodomethane are nonsuperimposable. (b) The mirror image forms of the molecule glyceraldehyde are nonsuperimposable. 14 7 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chirality Chiral – Nonsuperimposable on its mirror image. Achiral – Superimposable on its mirror image. If a molecule (or object) has a mirror plane or an inversion center, it cannot be chiral. 15 Chirality How can you predict whether a given molecule is or is not chiral? A molecule is not chiral if it has a plane of symmetry. 16 8 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chirality Chiral or Achiral? Brandy snifter achiral 17 Chirality Chiral or Achiral? Baseball glove chiral 18 9 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chirality Chiral or Achiral? cis-1,3-dimethylcyclopentane achiral mirror plane 19 Chirality Chiral or Achiral? trans-1,3-dimethylcyclopentane chiral 20 10 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chirality Asymmetric centers An asymmetric center is an atom that is bonded to four different groups. 21 Chirality Isomers with more than asymmetric center Organic molecules, especially monosaccharides, may contain more than one chiral center. D-Erythrose 22 11 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chirality Number of chiral carbons in ALDOSES Aldotriose- 1 Aldotetroses- 2 Aldopentoses- 3 Aldohexoses- 4 23 Chirality Number of chiral carbons in KETOSES Ketotriose- none Ketotetroses- 1 Ketopentoses- 2 Ketohexoses- 3 24 12 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Fischer Projection A two-dimensional representation for showing the configuration of tetrahedral stereocenters. Fischer- o Horizontal lines represent bonds projecting forward from the stereocenter. o Vertical lines represent bonds projecting to the Projection: rear. o Only the stereo center is in the plane. 25 L- and D-Monosaccharides: In 1891, Emil Fischer made the arbitrary assignments of D- and L- to the enantiomers of glyceraldehyde. D-monosaccharide: The -OH on its penultimate carbon is on the right in a Fischer projection. L-monosaccharide: The -OH on its penultimate carbon is on the left in a Fischer projection. 26 13 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 27 Cyclic Structure Aldehydes and ketones react with alcohols to form hemiacetals. Cyclic hemiacetals form readily when hydroxyl and carbonyl groups are part of the same molecule and their interaction can form a five- or six- membered ring. 28 14 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Haworth Projections A five- or six-membered cyclic hemiacetal is represented as a planar ring. The new carbon stereocenter created in forming the cyclic structure is called the Anomeric carbon. Stereoisomers that differ in configuration only at the anomeric carbon are called Glyceraldehyde Dihydroxyacetone Anomers. The anomeric carbon of an aldose is C-1; that of the most common ketose is C-2. 29 Converting Fischer to Haworth 1. Draw a Haworth’s “stem” 2. Number your atoms 1 through 5 starting from the anomeric carbon and going clockwise 3. If your sugar was D, then the carbon #6 is going to be looking “up” (down for the L sugar) 4. The “right” groups on carbons 2, 3, and 4 in the Fischer projection go onto the “bottom” positions in Haworth 5. The “left” groups on carbons 2, 3, and 4 in the Fischer projection go onto the “up” positions in Haworth 30 15 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Haworth Projections 31 Haworth Projections Terminologies: Pyranose - Cyclic monosaccharide containing a six-atom ring Aldohexoses form pyran ring Furanose - Cyclic monosaccharide containing a five-atom ring Aldopentoses and Ketohexoses form furan ring 32 16 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Haworth Projections Aldopentoses also form cyclic hemiacetals. The most prevalent forms of D-ribose and other pentoses in the biological world are furanoses. 33 Haworth Projections D-Fructose also forms a 5-membered cyclic hemiacetal. 34 17 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Haworth Projections Dextro and Levo Designation In a Haworth projection, the hemiacetal ring system is viewed “edge on” with the oxygen Haworth ring atom at the upper right (six-membered ring) or at the top (five-membered ring). Projection: In the D form, CH2OH is positioned above the ring. In the L form, which is not usually encountered in biochemical systems, the terminal CH2OH group is positioned below the ring. 35 Haworth Projections 36 18 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Haworth Projections Example: 2 Forms of Glucose 37 Chair Conformation For pyranoses, the six-membered ring is more accurately represented as a Strain-free chair conformation. 38 19 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Chair Conformation In both Haworth projections and chair conformations, the orientations of groups on carbons 1- 5 of b-D-glucopyranose are up, down, up, down, and up and all are equatorial. 39 Converting Haworth to Chair The trick is to remember that just like the Haworth projections, the chair conformations also have the well-defined “up” and “down” positions! Example. Haworth projection and chair conformation of glucopyranose 40 20 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Carbohydrate Derivatives 41 Amino sugars: Ø Contain an -NH2 group in place of an -OH group. Ø Only three amino sugars are common in nature: 42 21 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Biologically Relevant Carbohydrates 43 Monosaccharides 1. Glucose Most abundant in nature. Other names: Grape sugar Blood sugar Dextrose 6-membered cyclic form Important in human nutrition 44 22 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Monosaccharides 2. Galactose “Brain sugar” “Milk sugar” Used to differentiate between blood types. Six-membered cyclic form 45 Monosaccharides 3. Mannose Aldohexose Found in many fruits Important in the glycosylation of proteins in the body. Six-membered cyclic form 46 23 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Monosaccharides 4. Fructose Ketohexose Sweetest tasting of all sugars High dietary sugar due to sweetness Five-membered cyclic form 47 Monosaccharides 5. Ribose Part of a variety of complex molecules which include: RNA ATP DNA Five-membered cyclic form 48 24 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Disaccharides Contain 2 sugar units Two monosaccharides are joined by a glycosidic bond between the anomeric carbon of one unit and an –OH group of the other unit. 49 Disaccharides 1. Maltose Structurally made of 2 D-glucose units, one of which must be α-D-glucose, linked via an α(1→4) glycosidic linkage. Can be easily digested by humans. 50 25 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Disaccharides 2. Lactose Made up of β-D-galactose unit and a D-glucose unit joined by a β(1 → 4) glycosidic linkage. Lactase hydrolyzes β(1 → 4) glycosidic linkages. 51 Disaccharides 3. Sucrose The most abundant of all disaccharides and found in plants. Also known as the “Table sugar”. 52 26 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Disaccharides 4. Cellobiose Contains two D-glucose monosaccharide units, one of which must have a β configuration, linked through a β(1 4) glycosidic linkage. Cannot be digested by humans. 53 Oligosaccharides Carbohydrates that contain 3–10 monosaccharide units bonded to each other via glycosidic linkages. Commonly found in onions, cabbage, broccoli, and whole wheat. Can distinguish blood types. 54 27 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Oligosaccharides 55 Polysaccharides Polymers of many monosaccharide units bonded with glycosidic linkages. Polysaccharides are not sweet and do not show positive tests with Tollen’s and Benedict’s solutions, Limited water solubility. 56 28 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Polysaccharides 1. Starch 57 Polysaccharides 58 29 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Polysaccharides 2. Glycogen 59 Polysaccharides 3. Cellulose Linear homopolysaccharide with β(1 → 4) glycosidic bond. Humans do not have enzymes that hydrolyze β(1 → 4) linkages and so they cannot digest cellulose. 60 30 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Polysaccharides 4. Chitin Linear polymer with all β(1→4) glycosidic linkages. It has an N-acetyl amino derivative of glucose. 61 Polysaccharides 5. Hyaluronic acid Alternating residues of N-acetyl- β-D-glucosamine and D-glucuronate. Highly viscous and serve as lubricants in the fluid of joints as well as vitreous humor of the eye. 62 31 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 Polysaccharides: 6. Heparin Blood anticoagulant Acidic polysaccharide 63 Summary of Carbohydrates 64 32 FEU Biochemistry Cluster Property. Any forms of replication is prohibited. Seek approval from Ms.Jessa Natividad and Ms. Erika Viloria 8/13/24 WORKSHEET! ANSWER WORKSHEET 3: CARBOHYDRATES STRUCTURE AND FUNCTIONS ON CANVAS! 65 END THANK YOU FOR LISTENING! 66 33