PolysaccharidesAQA A-Level Biology: Flashcards

What these 13 flashcards ask

Which glucose isomer makes glycogen and starch?
Which glucose isomer makes cellulose?
What is the function of glycogen?
Why is glycogen well suited to storing energy?
What are the two polysaccharides in starch?
Why is amylose compact?
Why does starch not affect the water potential of a cell?
How is cellulose different from starch in its monomer?
Why are the glucose units in cellulose alternately inverted?
What holds cellulose chains together in microfibrils?
Why does a plant cell not burst in pure water?
How do you test for starch?
Where is starch stored in a plant?

Exam questions on Polysaccharides

A student compares three polysaccharides: glycogen from liver tissue, starch from a potato and cellulose from plant cell walls.
Explain how the structure of glycogen makes it suitable as an energy store in liver cells.2 marks
The muscle cells of a sprinter must release glucose for respiration very rapidly during a 100 m race. The cells of a potato tuber, by contrast, store starch for use over several weeks.
Explain why glycogen is better than unbranched amylose as a store of glucose for rapid release.2 marks
Plant cell walls contain cellulose. A plant cell placed in pure water takes in water by osmosis, but it does not burst.
Explain how cellulose molecules are arranged to give the cell wall strength.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).