Term
| 3.2.1 Distinguish between organic and inorganic compounds. |
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Definition
| All organic molecules contain the element carbon, although not all carbon-containing molecules are organic. |
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Term
| 3.2.2 Identify amino acids, glucose, ribose and fatty acids from diagrams showing their structure. |
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Definition
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Term
| 3.2.3 List three examples each of monosaccharides, dissacharides and polysaccharides. |
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Definition
Monosaccharides: glucose, galactose, fructose
Disaccharides: maltose, lactose, sucrose
Polysaccharides: starch, glycogen, cellulose |
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Term
| 3.2.4 State one function of glucose, lactose and glycogen in animals, and of fructose, sucrose and cellulose in plants. |
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Definition
Glucose: chemical fuel for cell respiration
Lactose: makes up some of the solutes in milk
Glycogen: stores glucose in liver and muscles
Fructose: found in many fruits (makes them sweet)
Sucrose: often transported from leaves of plants to other locations in plants by vascular tissue
Cellulose: one of the primary components of plant cell walls |
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Term
| 3.2.5 Outline the role of condensation and hydrolysis in the relationships between monosaccharides, disaccharides and polysaccharides; between fatty acids, glycerol and triglycerides; and between amino acids and polypeptides. |
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Definition
(Hydrolysis of a disaccharide to two monosaccharides)
lactose + water → glucose + galactose
(Hydrolysis of a polysaccharide to many monosaccharides)
starch + (many) water → (many) glucose
(Hydrolysis of a triglyceride lipid to glycerol and fatty acids)
triglyceride + 3 water → glycerol + 3 fatty acids
(hydrolysis of a polypeptide (protein) to amino acids)
protein + (many) water → (many) amino acids
(condensation of amino aicds to form a polypeptide)
(many) amino acids → protein + (many) water |
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Term
| 3.2.6 State three functions of lipids. |
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Definition
| Lipids are very efficient molecules for storing energy. They are also very important for thermal insulation. Phospholipids make up a double layer of all cell membranes. |
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Term
| 3.2.7 Compare the use of carbohydrates and lipids in energy storage. |
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Definition
| Both lipids and carbohydrates are used to store energy in living organisms. Lipid differs from carbohydrate though, as it stores approximately twice as much chemical energy as the carbohydrate. |
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