biological molecules intro to the carbohydrates
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TRANSCRIPT
Stanmore College Interview Presentation
Introduction to Biological Molecules
Lyndsae Drury Biology Lecturer
Biological molecules
• 1. Water
• 2. ions
• 3. Sugars, Carbohydrates
• 4. Proteins
• 5. Lipids
Carbohydrates
Carbohydrates contain 3 elements:
• Carbon (C)• Hydrogen (H)• Oxygen (O)
• Carbohydrates are found in one of three forms:
• Monosaccharides
• Disaccharides (both sugars)
• Polysaccharides
• Monosaccharides
• General formula:.
• (CH2O)n where n is a number between 3 and 9. They are classified according to the number of carbon atoms. The monosaccharides you will have to know fall into these categories:
• C = 3 = triose
• C = 4 = tetrose
• C = 5 = pentose
• C = 6 = hexose
• Trioses: (e.g. glyceraldehydes), intermediates in respiration and photosynthesis.
• Tetroses: rare.
• Pentoses: (e.g. ribose, ribulose), used in the synthesis of nucleic acids (RNA and DNA), co-enzymes (NAD, NADP, FAD) and ATP.
• Hexoses: (e.g. glucose, fructose), used as a source of energy in respiration and as building blocks for larger molecules.
• All but one carbon atom have an alcohol (OH) group attached. The remaining carbon atom has an aldehyde or ketone group attached.
• Chain form:
• Mono Saccharides
• Examples of Disaccharides
• Sucrose: glucose + fructose,
• Lactose: glucose + galactose,
• Maltose: glucose + glucose.
• Maltose: glucose + glucose.
Disaccharides
Starch made of two polysaccharides
Differences between Glycogen and Amylopectin polysaccharides.The branches are formed by linking C # 1 to a C # 6 through an acetal linkages. In glycogen, the branches occur at intervals of 8-10 glucose units, while in amylopectin the branches are separated by 12-20 glucose units
Other Novel Polysaccharides
Chitin polysaccharide found in crabs and sea shells whereas Lignin in wood