AQA A Level Biology Revision Questions and Detailed Answers

Describe how you would use a biochemical test to show that a solution contained a nonreducing sugar, such as sucrose. [3] ,first reducing sugars test; boil with dilute HCl acid then Neutralise with NaHCǑ, add benedict and heat to 95 degrees C brick red ppt forms if reducing sugar is present Describe a chemical test you could carry out to show that a piece of coconut contains lipids. [3] (Crush in) ethanol / alcohol; Add (to) water (Order of adding is critical for this point); Emulsion / white colour Explain what is meant by a polymer. [1] Molecule) made up of many identical/similar molecules/monomers/ subunits; Name the reaction which occurs when starch is broken down into maltose. [1] Hydrolysis What is the formula for lactose? [2] C12 ; H22Ō1 Describe how β-glucose molecule differs from a molecule of α-glucose. [1] H at top right end (instead of OH) / OH at bottom (carbon 1)