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Chapter 5 The Structure and Function of Macromolecules
Polymers
Polymer - a long molecule consisting of many identical or similar building blocks linked
by covalent bonds
Monomer - repeating unit that serves as the building blocks of a polymer
Dehydration reaction - a reaction in which two molecules are covalently bonded to each
other through loss of a water molecule (Fig 5.2)
Hydrolysis - a reaction in which polymers are disassembled. The reverse of a
dehydration reaction
Carbohydrates
Monosaccharide - single sugar (Fig 5.3 & 5.4)
Disaccharide - two sugars joined by a glycosidic linkage
Glycosidic linkage - a covalent bond formed between two monosaccharides by a
dehydration reaction (Fig 5.5)
Polysaccharides (Fig 5.6 – 5.8)
Starch
Glycogen
Cellulose
Chitin
Lipids
Hydrophobic molecules
Fat - a molecule constructed of glycerol and fatty acids
Fatty acids - a long carbon skeleton with an acid group at one end (Fig 5.11)
Saturated Fatty Acid - a carbon chain that has no double bonds
Unsaturated Fatty Acid - a carbon chain that has one or more double
bonds
Triacylglycerol (Triglycerides) - glycerol plus 3 fatty acids (Fig 5.10)
Phospholipids (Fig 5.12)
Steroids (Fig 5.14)
Proteins
Amino acids - organic molecules possessing both carboxyl and amino groups (Fig 5.15)
Polypeptide – polymer of amino acids
Peptide bond – covalent bond between two amino acids (Fig 5.16)
Conformation – 3D shape
Denaturation – loss of native conformation
Protein Functions (Table 5.1)
Structural
Storage
Transport
Hormonal
Receptor
Contractile
Defensive
Enzymatic
Protein Structure
Primary - unique amino acid sequence (Fig 5.18)
Secondary – alpha helices and beta pleated sheets (Fig 5.20)
Tertiary – hydrophobic interactions and disulfide bridges (Fig 5.22 & 5.17)
Quaternary - aggregation of polypeptide subunits (Fig 5.23)
Review (Fig 5.24)
Nucleic Acids
Gene - unit of inheritance
Nucleic acids - a class of organic compounds that consist of DNA and RNA
DNA – deoxyribonucleic acid
RNA – ribonucleic acid
Nucleotides - monomer of nucleic acids that is composed of a nitrogenous base, a fivecarbon sugar (pentose) and a phosphate group (Fig 5.29)
Nitrogenous bases
Pyrimidine - six-membered ring of carbon and nitrogen
Purine – six-membered ring fused to a five-membered ring
The Double Helix (Fig 5.30)
Base pairing - a purine will hydrogen bond to a pyrimidine. A to T or U; C to G
The two, polynucleotide strands of the double helix are complementary