- Biological Molecules
- Monomers linked together to form long chains
- Monomers usually based on carbon
- Polypeptides formed by linking together amino acids
- Reactions that produce water: Condensation
- Adding water to break down a polymer: Hydrolysis
- Test for reducing sugars
- Add 2cm3 food sample to a test tube.
- Add 2cm3 Benedict's reagent.
- Heat mixture in water bath for 5 minutes.
- Colour change from blue- orange/brown
- Test for non-reducing sugars
- Reducing sugars test. Solution stays blue: reducing sugar nor present
- Add 2cm3 food sample to 2cm3 dilute HCl. Place in heated water bath for 5 mins.
- Slowly add sodium hydrogencarbonate solution. Test with pH paper to ensure solution is alkaline
- Repeat Benedict's test. Colour change indicates non-reducing sugar has been hydrolysed into reducing sugars.
- Test for starch
- Place 2cm3 sample into test tube
- Add two drops of iodine solution and shake
- Blue-black colouration indicates presence of starch
- Made in a condensation reaction
- Joined by a glycosidic bond
- Two alpha glucose monosaccharides form a maltose disaccharide.
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