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25 Cards in this Set
- Front
- Back
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How many bonds can Carbon, Oxygen and Hydrogen |
4, 2 and 1 bond |
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What does glucose and glucose form |
Maltose |
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What does glucose and fructose form |
Sucrose |
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What does glucose and galactose form |
Lactose |
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What is an isomer |
An isomer is a compound with the same chemical formula but different chemical structure |
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Why are monosaccharides soluble |
The H and OH can hydrogen Bond with the water |
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What is the arrangement of the hydroxyls in the alpha glucose molecule |
Down, down, up, down |
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What the the arrangement of hydroxyls in the beta glucose molecule |
Up. Down. Up. Down |
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What is the Benedicts test |
A chemical test that changes colour in the presence of a reducing sugar |
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What is the method of conducting the Benedicts test |
• add 2 cm cubed of food sample into a test tube if it isn't in liquid form grind it up. •add an equal volume of Benedicts solution •heat mixture gently in boiling water bath for 5 minutes |
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If a reducing sugar is present in the Benedicts test, what are range of colours starting from the least concentrate to the most concentrate |
Green, yellow, orange brown and brick red |
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Why is the Benedicts test a semi quantitative method? |
It gives an estimate amount of reducing sugar |
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How can you make the Benedicts test quantitative |
•Measure the weight of the precipitate at different concentrations. •Draw a graph showing the relationship between the weight of precipitate and concentration. •measure mass of unknown precipitate and plot it on the graph and show the concentration |
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What is the test for non reducing sugars |
•Hydrolyse the glycosidic Bond by heating the sugar with HCL(aq) •neutralise the acid by adding NaHCO3 •Conduct Benedicts test |
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What is the biochemical test for starch |
Add 2-3 drops of iodine solution. Of the colour changes from colourless to blue-black then starch is present |
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What monomers with what bonds make up glycogen |
Alpha glucose with 1-4 and 1-6 glycosidic bonds |
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What monomers with what bonds make up cellulose |
Beta glucose with 1-4 glycosidic bonds and hydrogen bonding between molecules to form micro-fibrills. |
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What structure does glycogen have |
Highly branched helix structure |
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Why does glycogen have a high surface area and where is it stored? |
It has lots of ends so it can be quickly broken down by enzymes and it is stored in the muscles and liver. |
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What is the structure and what bonds make up starch? |
It forms a branched or unbranched helix shape. |
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Why is starch good for energy storage? |
It is compact, so lots can be stored in a small place. When hydrolysed, it forms alpha glucose. It's large and insoluble so it doesn't diffuse out of cells or affect water potential, water is not drawn into cell by osmosis.
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Why is the branched form of starch great for energy storage? |
If it is branched, it has many ends (high surface area) which can be acted on by enzymes simultaneously which releases glucose monomers very rapidly. |
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Starch is never found in animal cells, what acts in animal cells that is similar to starch? |
Glycogen |
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Why is glycogen good as a major carbohydrate storage? |
It's large and insoluble so it doesn't diffuse out of cells or affect water potential, water is not drawn into cell by osmosis.It's compact, so alot can be stored in small places. It has lots of ends (more than starch) so it can be acted on simultaneously by enzymes to release glucose monomers rapidly. |
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Why is glycogen more suitable for animals? |
Animals have a higher metabolic and respiratory rate than plants and glycogen has more ends than starch so the enzymes can break it down quicker to support it's metabolic rate and respiratory rate. |
