Which molecule is required for this reaction to occur?

2.1.1 describe and carry out the Benedict’s test for reducing sugars, the iodine test for starch, the emulsion test for lipids and the biuret test for proteins

2.1.2 describe and carry out a semi-quantitative Benedict’s test on a reducing sugar solution by standardising the test and using the results (time to first colour change or comparison to colour standards) to estimate the concentration

2.1.3 describe and carry out a test to identify the presence of non-reducing sugars, using acid hydrolysis and Benedict’s solution

2.2.1 describe the ring forms of α-glucose and β-glucose

2.2.10 relate the molecular structure of triglycerides to their functions in living organisms

2.2.11 describe the molecular structure of phospholipids with reference to their hydrophilic (polar) phosphate heads and hydrophobic (non-polar) fatty acid tails

2.2.2 define the terms monomer, polymer, macromolecule, monosaccharide, disaccharide and polysaccharide

2.2.3 describe the formation of a glycosidic bond by condensation, with reference both to polysaccharides and to disaccharides, including sucrose

2.2.4 state that glucose, fructose and maltose are reducing sugars and that sucrose is a non-reducing sugar

2.2.5 describe the formation of a glycosidic bond by condensation, with reference to disaccharides, including sucrose, and polysaccharides

2.2.6 describe the breakage of a glycosidic bond in polysaccharides and disaccharides by hydrolysis, with reference to the non-reducing sugar test

2.2.7 describe the molecular structure of the polysaccharides starch (amylose and amylopectin) and glycogen and relate their structures to their functions in living organisms

2.2.8 describe the molecular structure of the polysaccharide cellulose and outline how the arrangement of cellulose molecules contributes to the function of plant cell walls

2.2.9 state that triglycerides are non-polar hydrophobic molecules and describe the molecular structure of triglycerides with reference to fatty acids (saturated and unsaturated), glycerol and the formation of ester bonds