Sugar
Revision as of 08:45, 16 September 2018 by NRJC (talk | contribs) (Created page with "==Key Stage 3== ===Meaning=== Sugar is a simple carbohydrate found in food and is a source of energy for respiration. ===About Sugar=== ====Sugar Molecules==== :...")
Contents
Key Stage 3
Meaning
Sugar is a simple carbohydrate found in food and is a source of energy for respiration.
About Sugar
Sugar Molecules
- Sugar molecules are simple and the body can quickly get energy from them.
- You should know:
- Glucose - A sugar found in syrup and sweets.
- Fructose - A sugar found in fruits.
- Sucrose - Found in white sugar which is made of one glucose molecule and one fructose molecule bonded together.
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| There are many different sugar molecules. These are just three examples. |
Sugar in foods
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| Fruit has lots of sugar but is healthy because it also has vitamins and fibre inside. | Yoghurt has a lot of sugar but there are also some health parts like a mineral called Calcium. | Sweets are full of sugar with nothing healthy in them. | Energy drinks have nothing healthy in them and are packed with sugar. |
Testing For Sugars
- Glucose and Fructose can be detected with the Benedict's Test.
- Sucrose cannot be detected with the Benedict's Test unless you first react it with dilute hydrochloric acid.
Method=
1. A sample of food is dissolved in water. 2. The solution is added to blue Benedict's solution in a boiling tube. 3. The solution is kept at 90°C for up to 10 minutes. 4. A colour change indicates the presence of glucose or fructose. If they are present the solution will eventually turn brick red or brown.
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| When sugar is present the Benedict's solution turns from blue through several colours until it becomes brick red or brown.
If this was done with sucrose the Benedict's solution would stay blue. |