Baking cakes with different recipes can provide an exercise in the application of the scientific method, illustrating the need to vary only one ingredient at a time for correct derivation of conclusions. This experiment, most likely to be performed at home, compares a cake flour with flours from durum wheat, rice and cornflour (gluten-free…

Proteins are a diverse class of biochemical macromolecules, including substances as (apparently) unrelated as silk and sinew, hair and horn, feathers and flagella, enzymes and epidermis, gelatine (jelly) and gluten and gore, spider web, meat and fish muscle. Yet they are unified by being polymers of amino acids. Discovery of the nature of proteins…