(carbon-based compounds) Organic Compounds (carbon-based compounds)

Functional Groups the unique properties of organic compounds are due to their size, shape, & functional groups: hydroxyl (–OH) carbonyl (=C=O) carboxyl (–COOH) amino (–NH2) phosphate (–OPO32–)

Organic Macromolecules large biological molecules 4 main classes: carbohydrates lipids proteins nucleic acids cells synthesize them by linking small organic molecules (monomers) into long chains (polymers)

Making & Breaking Polymers dehydration synthesis monomers are linked together by removing a molecule of water hydrolysis bonds between monomers are broken by adding a molecule of water

Carbohydrates elements = C,H,O monomers are called monosaccharides generally have molecule formulas that are some multiple of CH2O (ex) glucose = C6H12O6 main fuel for cellular work disaccharides = 2 linked monosaccharides (ex) sucrose = glucose + fructose polysaccharides = polymers of monosaccharides

Examples of Polysaccharides starch – storage molecule made up of glucose monomers (found in plants) glycogen – storage molecule made up of glucose monomers (found in animals – liver & muscle tissue) cellulose – structural compound found in the cell walls of plant cells

Lipids elements = C,H,O mostly nonpolar ( not attracted to water) examples: fats – energy storage phospholipids – major component of cell membranes waxes – help prevent desiccation steroids – (ex) cholesterol used to make sex hormones found in cell membranes to help maintain fluidity

Fats made up of glycerol & fatty acids saturated fats  the fatty acids “straight” the fat forms a solid at room temperature unsaturated fats  the fatty acids are “kinked” due to double bonds between carbon atoms the fat forms a liquid at room temperature

Proteins elements = H, O, N, C monomers = amino acids contain an amine group & a carboxyl group 20 different kinds (each has a different “R” group) polypeptide = chain of linked amino acids peptide bond = type of covalent bond that links 2 amino acids together

Examples of Proteins enzymes – biological catalysts (speed up the rate of chemical reactions) collagen – structural protein in hair actin & myosin – contractile proteins in muscle antibodies – defensive proteins hemoglobin – transport protein (O2 & C O2) membrane proteins – transport materials across cell membrane ovalbumin – storage protein found in egg white to support developing embryo

Protein Structure – 4 levels: primary – chain of amino acids (polypeptide) secondary – polypeptide coils or folds into an -helix or -pleated sheet tertiary – the -helix or -pleated sheet folds into a globular or fibrous shape protein is functional at this level denaturation = process by which proteins unravel, losing their specific shape &, thereby, their function causes = excessive heat, changes in pH quaternary – association of two or more tertiary proteins

Nucleic Acids elements = C,H,O,N,P monomers = nucleotides 5 kinds: adenine (A), thymine (T), cytosine (C), guanine (G), and uracil (U) basic structure: phosphate group 5-carbon sugar nitrogenous base (A, T, C, G, or U)

Examples of Nucleic Acids DNA (deoxyribonucleic acid) composed of two chains of nucleotides (polynucleotides) twisted into a double helix built from the nucleotides A, T, C, & G type of sugar in DNA nucleotides = deoxyribose RNA (ribonucleic acid) composed of one chain of nucleotides built from the nucleotides A, U, C, & G type of sugar in RNA nucleotides = ribose