AQA A-level Biology paper 1 Questions and Answers Graded A+

large molecules often contain carbon. why? they can readily form bonds with other carbon atoms. this forms a 'backbone'. other atoms can then attach. describe benedicts test for reducing sugars add equal volumes of the sugar sample and benedicts reagent. heat the mixture in a water bath for 5 minutes. brick red precipitate will form. what is a reducing sugar? a sugar that can reduce (give electrons to) another chemical. describe the benedicts test for non reducing sugars with food sample, add an equal volume of dilute hydrochloric acid in a test tube. place test tube in water bath for 5 mins. add sodium hydrogencarbonate solution. heat resulting solution with an equal volume of benedicts. solution for 5 minutes. turns orange/brown.