*8(b)(iii)
General description
- bacteria and fungi are decomposers
- decomposers release enzymes for decomposition
- digested molecules are absorbed into the decomposer
- release carbon dioxide
Details of decomposition of carbohydrates
- carbohydrases are needed to breakdown carbohydrates
- hydrolysis of glycosidic bonds
- to form monosaccharides
- monosaccharides taken up by diffusion
- glucose used in respiration
- carbon dioxide produced by respiration of glucose Specific detail relating to carbohydrates in the table
- one glycosidic bond broken in disaccharides, two in trisaccharides, three in tetrasaccharides
IGNORE references to starch and amylase
- using one / two / three water molecules
- e.g. sucrose broken down into glucose and fructose
- monosaccharides do not need breaking down
(6)
Level 1 : general description of decomposition
1 mark : one point made
2 marks : three points made
Level 2 : details about decomposition of carbohydrates
3 marks : two points made
4 marks : three points made
Level 3 : specific details relating to carbohydrates in the table + mention of respiration releasing carbon dioxide
5 marks : specific detail given for either di / tri / tetra saccharides
6 marks : specific detail given for two of the three types of saccharides