macromolecules

Deoxyribonucleic Acids

• It is a polymer made up of nucleotides (adenine, thymine, cytosine, guanine), ribose sugar, and phosphate.
• It contains phosphodiester bonds, hydrogen bonds, and glycosyl bonds.
• The functional groups in this macromolecule are carbonyl and hydroxyl groups.
• Functions: contains genetic material for inheritance and replication, protein synthesis, and reproduction
• Characteristics: it has a double helix shape with the two strands running antiparallel to each other.

Carbohydrates

(maltose)

• Empirical formula: (CH₂O)_n 
• Carbohydrates may be classified into three groups: monosaccharides, oligosaccharides, and polysaccharides.
• Simple sugars can have spatial arrangement of their atoms, forming isomers with different chemical properties (e.g. glucose, galactose, and fructose)
• Monosaccharides are monomers that can undergo condensation reaction to form dimers (e.g. maltose, sucrose), or polymers.  
• Bonding between the monomers are glycosidic linkage (covalent bonds), the condensation reaction also produces a biproduct of water
• Function: energy storage, structural support, building materials, cell surface markers for cell-to-cell identification and communication
• Characteristics of Carbohydrates (polymers): can be straight chain or branched
• Examples: fructose, glucose, sucrose maltose, lactose, amylose, amylopectin, cellulose, glycogen, chitin

Proteins

(keratin)

• Amino acid polymers folded into specific 3-D shapes.  Its structural characteristics determine its function.
• An amino acid is an organic molecule with a central carbon atom attached to an amino group, a carboxyl group, a hydrogen atom, and an R chain.
• Monomers of protein polypeptide bonds to form polypeptide chains into polymers through condensation reaction
• Functions: signal transduction, cell cycle regulation, differentiation, structural building blocks
• Characteristics: may be polar, nonpolar, or charged, low molecular weight
• Examples: keratin, fibrin, collagen

Lipids

(cholesterol)

• Hydrophobic molecules composed of carbon hydrogen, and oxygen.
• They are polar molecules
• Lipids can be divided into four families: fats, phospholipids, steroids, and waxes.
• Triglycerides are lipids containing three fatty acids attached to a single molecule of glycerol
• Glycerol reacts with fatty acids through a condensation reaction between the hydroxyl group of glycerol and the carboxyl group of a fatty acid.  The bond is called an ester linkage. (esterification)
• Functions: energy storage, membrane structure, hormones, vitamins
• Examples: cholesterol (steroids), testosterone, butter, cutin, beeswax