BIOMOLECULES You are what you eat: CARBOHYDRATES LIPIDS PROTEINS NUCLEIC ACIDS.

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    29-Dec-2015

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  • BIOMOLECULESYou are what you eat:CARBOHYDRATES LIPIDSPROTEINSNUCLEIC ACIDS

  • Carbohydrates

  • MONOSACCHARIDESAll have the formula (CH2O)nThe most common and important monosaccharide is glucose, which is a six-carbon or hexose sugar, so has the formula C6H12O6.

  • Glucose is the most abundant organic compound in nature.Reactions of cellular respiration transform glucose into ATP energy.Most important sugar in our dietDiabetics lack hormone insulin, which allows glucose to enter into cells to be used in mitochondria.

  • There are many isomers of glucose, (same chemical formula but different structural formulae). These isomers include fructose and galactose. Fructose: found in honey, tree fruits; berries; melons; and some root vegetables, such as beets, sweet potatoes, parsnips and onions

  • Galactose: found in dairy products, in sugar beets and gums. Galactose is less sweet than glucose and not very water-soluble. Humans do not have the enzymes needed to use galactose directly. It must be converted into glucose first.

  • DisaccharidesSugars that consist of two monosaccharides, joined by a glycosidic bond.Examples are: maltose (glucose-glucose), sucrose (glucose-fructose), and lactose (galactose-glucose)The formation of a glycosidic bond involves the formation of water as a by-product and is a dehydration synthesis reaction. (aka: condensation reaction)

  • PolysaccharidesLarge carbohydrate chains made up of more than 10 subunits.Are a way of storing glucose until it is required starch in plants and glycogen in humansAlso structural role: cellulose makes up plant cell wall

  • LIPIDSDiverse group: fats, phopholipids,steroids, and waxesStructurally: are not made up of repeating sub units. Common Properties: they are all hydrophobic and do not dissolve in waterThey all contain hydrogen, oxygen and carbon

  • 4 types of lipids:1.Fats aka Triglycerides long term energy storage. concentrated source of energy- 1 g of fat has more than twice the energy of 1 g of carbohydrateAlso cushion organs and insulate

  • Structure of fats: 3 fatty acids + glycerol = triglycerideFormed by dehydration synthesis reaction

  • Fatty acids have long hydrocarbon chains with a carboxyl group at one end.

  • Saturated fatty acids can lie closely together and form weak Van der Waal bonds between molecules. They are solids at room temperature. They are usually animal fats.

  • Unsaturated fats are loosely packed because of the kinks in the hydrocarbon chain. They are oils at room temperature, and are usually from plants.

  • Trans-fatty acids: the hidden fatsare produced when hydrogen is added to unsaturated fats. (Hydrogenation)Trans fats are solids at room temperatureTrans fats cause significant and serious lowering of HDL (good) cholesterol and a significant and serious increase in LDL (bad) cholesterol; make the arteries more rigid; cause major clogging of arteries; cause insulin resistance; cause or contribute to type 2 diabetes, and heart disease. Now mandatory labeling of amount of trans fats in Canada. ( December 12, 2005)

  • Phospholipids: are part of cell membrane. They help to regulate what substances can enter cells and which cant.

  • Steroids: cholesterol ( important in cell membranes), hormones such as testosterone and estrogen.They all have a 4 ring structure

  • Waxes: are formed from fatty acids and long-chain alcohols. They are commonly found wherever waterproofing is needed, such as in leaf cuticles, insect exoskeletons, birds' feathers and mammals' fur.

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