4 Major types of biological macromolecules:1. Proteins - do the vast majority of work; cell structure2. Nucleic Acids- DNA and RNA3. Carbohydrates (or Polysaccharides) (sugars)4. Lipids (fats) - "not every lipid is a fat MC"Macromolecules - 26% of a cell- 60% of that is protein- Made up of MONOMERS (building blocks of Macromolecules)- proteins - amino acids- nucleic acids - nucleotides- polysaccharides - monosaccharides- lipids- fatty acids- Synthesized by DEHYDRATION SYNTHESIS/CONDENSATION reactions and broken down by HYDROLYSIS reactions - Dehydration Synthesis - H20 is a byproduct; Potential Energy stored - Hydrolysis - H20 is added and Energy is released - Reversible reactions!!!!- All monomers are linked by covalent bonds;1. Polysaccharides/Carbohydrates - made from condensation reactions bringing together monosaccharides - uses: 1. energy sources - ex: glucose 2. structural molecules - chitin;cellulose 3. cell identification and recognition - surface markings on cells; sugars (ex: glycoproteins/glycolipids) - "carbohydrate" can either mean polysaccharide or monosaccharide - General form chemically: - C2H202 - Cn(H20)n ** # of Carbons = # of H20 Molecules!! - Standard conventions for atoms in ring structures: - Within the ring- if not told explicitly, it's Carbon (C) - number carbons from left to right! :) - Above or below the ring- it not told explicitly, it's Hydrogen (H) - Monosaccharides typically found in lengths of 3, 5, or 6 carbons - 6 Carbons = HEXOSE SUGAR - ex: GLUCOSE - C6H12O6 - In linear form: C=O at Carbon #1 = ALDEHYDE -- so glucose is an Aldose sugar - If C=O at Carbon #2 = KEYTONE -- ex: fructose - If Hydrogen is AHHHbove the ring? - Alpha Glucose - If Hydrogen is BEEElow the ring? - Beta Glucose - Both are molecules of Glucose, but are different MCs - 3 Carbons = TRIOSE SUGAR - Glycerol: 3 Carbon Backbone w/ OH (Hydroxyl) on each carbon; the rest filled with Hydrogens - But a glycerol MC with a C=O at Carbon #1 = GLYCERALDEHYDE - C3H6O3 - NEVER FOUND IN CIRCULAR FORM; always straight chain form because its not long enough - 5 Carbons = PENTOSE SUGAR - Ex: Ribose - C5H10O5 - Some monosaccharides have identical formulas but different structures - ISOMERS - isomers of Glucose (C6H12O6): -a-Mannose -a-Galactose - Fructose - just b/c it has a 5 member Carbon Ring doesn't make it a Pentose- COUNT CARBONS!!* - Other Monosaccharides have similar formulas, similar structures, and related functions: - TRICK B/C THEY LOOK LIKE ISOMERS! - Ribose (C5H10O5) and Deoxyribose (C5H10O4) ---Examine Carefully! - Two monosaccharides can be brought together to form a disaccharide via acovalent bond - GLYCOSIDIC LINKAGE!!!! - a-1,4 glycosidic linkage - b-1,4 glycosidic linkage - only care about Carbon #1, whether its in the alpha or beta configuration - Maltose & Cellobiose, both monosaccharides are glucose, but not all disaccharides are the same monomers - Ex: Lactose = glucose + galactose - Ex: Sucrose = glucose + fructose - The chemical formula for a disaccharide of hexose sugars is C12H22O11 - This differs because H2O IS LOST!! Lost in the condensation reaction - Nomenclature: - 1 monomer = monosaccharide - 2 monomers = disaccharide - several monomers = oligosaccharide (like a chain of 4 because "oglio" =few) - Hundreds or thousands of monomers = polysaccharide - Carbohydrates/Polysaccharides can be modified - linkage of oligosaccharides to other macromolecules , such as a protein or a lipid - when covalently linked to membrane proteins or lipids, carbohydratesact as recognition and identification MCs (chem markers) - glycoproteins and glycolipids (BLOOD TYPING) - addition of chemical groups, such as Phosphate (Pi) groups and amine groups (NH2) - ex: glucose => glucoseAMINE , which can be chitin if further modified - ex: galactose => galactosAMINE , joint/joint substances - Polysaccharides serve as (1) chemical sources of energy or (2) structural compounds - Cellulose - Starch - Glycogen 1. Cellulose => PLANT CELL WALLS! - the most abundant carbon-containing (organic) compound on the face of the Earth - found in plant cell walls - the primary component in fact :D - linear, unbranched polymer of glucose (fibril) - "just glucose linked to glucose" through b-1,4 glycosidic linkages - glucose (b-1,4 glycosidic linkage)glucose (b-1,4 glycosidic linkage)glucose (b-1,4 glycosidic linkage) - fibrils held together by hydrogen bonding between the individual fibrils ||||||||| - "by convention" the second molecule is upside down - "if it doesn't fit,it won't work". - SO - "rotate #2 MC 180degrees" 2. Starch => FOOD! - found chiefly in seeds, fruits, tubers, roots, and stems ofplants; energy storage - LOOSELY branched
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