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1. a) Difference between protein and polypeptide:
Proteins have a structure formed by one or more polypeptide chains whilst a polypeptide is a chain of amino acids. b) Fat and oil differences: They are both lipids, but fats are solid whilst oil are liquids.
c) Difference between starch and glycogen:
Starch is a polysaccharide found in plant tissue whilst glycogen has polysaccharide found in animals.
d) Condensation and hydrolysis:
Condensation is a chemical process by which 2 molecules are joined together to make a larger, more complex, molecule, with the loss of water. Instead, hydrolysis consists in splitting and adding water.
e) Hydrophobic and hydrophilic:
Hydrophobic avoids water, whilst hydrophilic is attracted by it.
2. a) Hydrolysis of maltose: glucose + glucose = maltose + H2O
b) The condensation reaction that forms a triglyceride:
Glycerol + 3 fatty acids = triglyceride + 3H2O
c) Hydrolysis of starch to remove a single molecule:
Starch + H2O = 3 glucose
3. The transparency of water is important to life because it allows organisms living in water to absorb the sunlight and carry out photosynthesis. If water was opaque, the sunlight wouldn’t be able to enter. Because they wouldn’t be able to conduct photosynthesis, plants would be unable to grow underwater.
Biology SL – Chapter 4 questions
Page 57
1. a) Difference between protein and polypeptide:
Proteins have a structure formed by one or more polypeptide chains whilst a polypeptide is a chain of amino acids. b) Fat and oil differences: They are both lipids, but fats are solid whilst oil are liquids.
c) Difference between starch and glycogen:
Starch is a polysaccharide found in plant tissue whilst glycogen has polysaccharide found in animals.
d) Condensation and hydrolysis:
Condensation is a chemical process by which 2 molecules are joined together to make a larger, more