Glossary

• Amino group = functional group of amino acid consisting of a nitrogen atom bonded to two hydrogen atoms
• Benedict's test = test for the presence of sugars in a food sample
• Biuret test = test for the presence of proteins in a sample
• Carboxyl group = combination of the functional hydroxyl and carbonyl group
• Condensation reaction = two molecules joining together to form a new chemical bonds and releasing a water molecule
• Disaccharide = formed when two monosaccharides join together
• Disulphide bonds = strong covalent bond formed between sulphur atoms
• Emulsion test = used to test for the presence of fats in a sample
• Fructose = monosaccharide found in plants
• Galactose = monosaccharide sugar about as sweet as glucose
• Glucose = hexose sugar - monosaccharide with 6 carbon atoms
• Glycerol = backbone of lipids
• Glycosidic bonds = forms between two monosaccharides and releases a water molecule
• Hydrogen bond = weak electrostatic forces of attraction between the hydrogen of one molecule and the oxygen or nitrogen of another
• Hydrolysis = reaction breaking chemical bond between monomers using a water molecule
• Hydrophilic = attracts water molecules
• Hydrophobic = repels water molecules
• Ionic bonds = electrostatic attraction between oppositely charged ions
• Lactose = disaccharide sugar made of glucose and galactose
• Maltose = formed when two alpha-glucose molecules join together by a condensation reaction
• Monomer = small basic molecular units
• Monosaccharide = simplest form of sugar
• Monounsaturated fatty acid = one double carbon bond in the fatty acid chain
• Non-reducing sugar = sugar that can't donate electrons to other molecules
• Osmosis = the movement of water molecules from a region of high water concentration to a region of low water concentration
• Peptide bond = bonds formed between amino acids
• Phospholipid = form of triglyceride except one fatty acid molecule is replaced by a phosphate group
• Polymer = complex molecules made of long chains of monomers
• Polypeptide = formed when more than two amino acids join together by condensation reactions
• Polar = structure with uneven distribution of electron density
• Polysaccharide = formed when more than two monosaccharides are joined together by condensation reactions
• Polyunsaturated fatty acid = fatty acids that contain two or more carbon double bonds
• Reducing sugar = sugar capable of acting as a reducing agent
• R-group = group on proteins giving amino acids specific characteristics
• Saturated fatty acid = doesn't contain carbon double bonds
• Starch = mixture of amylose and amylopectin
• Sucrose = disaccharide made of glucose and fructose
• Triglyceride = type of lipid derived from glycerol and three fatty acids
• Unsaturated fatty acid = have at least one double bond between carbon atoms
• Water potential = likelihood of water molecules to diffuse out of or into a solution