4. Biological molecules

4.1 Biological molecules 

• List the chemical elements that make up: 

1. carbohydrates 

2. fats 

3. proteins 

• State that large molecules are made from smaller molecules, limited to: 

1. starch and glycogen from glucose – cellulose from glucose 

2. proteins from amino acids 

3. fats and oils from fatty acids and glycerol 

• Describe the use of: 

1. iodine solution to test for starch 

2. Benedict’s solution to test for reducing sugars 

3. biuret test for proteins

4. ethanol emulsion test for fats and oils

5. DCPIP test for vitamin C 

6. State that water is important as a solvent 

Supplement:

1. two strands coiled together to form a double helix – each strand contains chemicals called bases – cross-links between the strands are formed by pairs of bases 

2. the bases always pair up in the same way: A with T, and C with G (full names are not required) 

• Describe the roles of water as a solvent in organisms with respect to digestion, excretion and transport