3.2.1 Distinguish between organic and inorganic compounds (2). Distinguish means to give the differences between two or more different items. Organic compounds are based on carbon and are found in living things. There are a number of exceptions including hydrogen carbonate (HCO3- ), carbon dioxide (CO2 )and Carbon monoxide (CO). Inorganic compounds are by default all the molecules other than those in the category above. Identify amino acids, glucose, ribose and fatty acids from diagrams showing their structure(2). Identify means to find an answer from a given number of possibilities. The following are examples of the most common organic molecules in living things: Monosaccharide sugars. These are the monomers from which larger polymer molecules are constructed. Molecules like glucose and fructose are metabolically active molecules usually stored in an inactive, insoluble polysaccharide form.
Glucose: C6H12O6 this is a hexose sugar (six carbons) most commonly found in this ring structure. Glucose will be known to most students as a product of photosynthesis or the substrate molecule for respiration. Glucose is also found in a polymer as starch, glycogen or cellulose. All bonds are covalent.
Glucose is a reducing sugar and will give positive (Brick red) precipitate in a Benedicts test. Glucose is metabolically active compound
Glucose is soluble and has osmotic effects when in solution
This is an alternative diagram of glucose where the carbons are assumed to be at each of the corners or ends of the lines (bonds). In this image the carbons are numbered so you can compare to the diagram above. Normally such numbers would be omitted form a diagram. These shorthand diagrams allow organic molecules to be drawn faster. There are examples further down the page of this type of diagram.
Ribose: Pentose (5 carbon sugar).
Ribose is part of one the important organic molecules in photosynthesis,...