CAIE A Level Biology 9700 · Biological molecules

Biological molecules: explain question

Explain4 marksStandard

A student prepares a solution of glucose and fructose and carries out a condensation reaction to form the disaccharide sucrose. Explain how the sucrose molecule is formed and why the resulting solution does not give a positive Benedict's test before hydrolysis.

How this question is marked

4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.

Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.

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