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