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Research is being conducted into the development of new biofuels - VCE - SSCE Chemistry - Question 7 - 2009 - Paper 1
Question 7
Research is being conducted into the development of new biofuels. It is known that a type of bacteria, clostridium acetobutylicum, converts cellulose to butanol. Th... show full transcript
Worked Solution & Example Answer:Research is being conducted into the development of new biofuels - VCE - SSCE Chemistry - Question 7 - 2009 - Paper 1
Step 1
a. Identify one step that represents an overall reduction reaction.
Answer
The step that represents an overall reduction reaction is the conversion of carbon dioxide into glucose. In this process, carbon dioxide () is reduced as it gains electrons, resulting in the formation of glucose ().
Step 2
Step 3
c. Explain, in terms of the structure of these two molecules, why this is the case.
Answer
Sucrose and 1-butanol differ significantly in their molecular structure. Sucrose is a disaccharide formed from glucose and fructose, containing many hydroxyl () groups, which lead to extensive hydrogen bonding with water molecules. This accounts for its high solubility in water. In contrast, 1-butanol is a smaller molecule with only one hydroxyl group. It has fewer polar interactions and thus forms limited hydrogen bonds with water, making it less soluble. The size and complexity of the sucrose molecule contribute greatly to its solubility.
Step 4
d. Why does the breakdown of sucrose require the presence of both water and sucrose?
Answer
The breakdown of sucrose into its monosaccharide components (glucose and fructose) requires water to facilitate hydrolysis. Water molecules provide the necessary medium for the enzyme sucrase to act, which cleaves the glycosidic bond in sucrose. The presence of sucrose is essential as it is the substrate upon which this enzymatic reaction occurs. Without both components, the reaction cannot proceed.