2Macronutrients ENERGY ‘BIG’ nutrients – these are complex ‘chemicals’ XS stored as FATBroken down into glucoseStored as glycogenCarbohydratesCellular respirationENERGYGlucose + oxygen water + carbon dioxide + ENERGY
3Other macronutrients… Lipids: ENERGYstored in body fatand found in membranesProteins: growth and repair
4Micronutrients The body only needs VERY SMALL amounts of these Inorganic Ions:Calcium (Ca2+) for teeth, muscles, bones, blood clottingSodium (Na+) for nerves, heartbeat, muscle contractionMagnesium (Mg2+)Iron (Fe2+)Phosphate (PO43-)Vitamins: complex organic substanceswater soluble (in blood) e.g. vit Cfat soluble e.g. vit A
5Vitamin CVitamin C: connective tissue, bones, skin, teeth, endothelial cellsdeficiency can lead to scurvycan contribute to CVD
6Water & fibre: (roughage) holds waterprovides bulk for intestinal muscles to work on
8Carbon Chemistry! 2D version Long chain of C atoms The very lazy scientist….
9Branched chain carbon polymer Carbon ring structuresBuckminsterfullerine (‘Buckyball’)
10Carbon Chemistry KEY FACTS Organic molecules contain: Carbon, hydrogen, oxygen, (sulphur, nitrogen, phosphrous)One carbon atom can bond with four other atoms forming a TETRAHEDRAL shapeThe bits of the body that are not WATER are ORGANIC moleculesCarbon can form long chains, branched chains or ring structuresThey can ‘fold-up’ to make three-dimensional structures
11Carbohydrates (CHO’s) Sugars: sucrose (white crystalline ‘sugar’)glucose (energy supplier – sports drinks)starch (flour, potatoes)Carbohydrates fall into four main groups:Monosaccharides (one ‘sugar-structure’)Disaccharides (two ‘sugar-structures’)Oligosaccharides (3-11 ‘sugar-structures’)Polysaccharides (over 11 ‘sugar-structures’)
12Monosaccharides (‘simple’ sugars) trioseMonosaccharides (‘simple’ sugars)Just one sugar-structureHave an empirical formula of (CH2O)nriboseTriose – found in mitochondriaPentose – found in DNA or RNAHexose – glucosegalactosefructoseglucoseEmpirical formula for hexoses is C6H12O6
16SIDE CHAINS AFFECT THE WAY IN WHICH THE MOLECULE IS USED BY THE BODY Monosaccharides you need to know…SIDE CHAINS AFFECT THE WAY IN WHICH THE MOLECULE IS USED BY THE BODYall of the carbon atoms are numbered 1-6α-glucose has a side chain at position 6fructose has a side chain at position 1 and position 6
18DisaccharidesThese are 2 monosaccharides JOINED TOGETHERglucose + glucose makes MALTOSEglucose + fructose makes SUCROSEglucose + galactose makes LACTOSEMonosaccharides join together by CONDENSATION REACTION and the bond that joins them together is a GLYCOSIDIC BOND
23(break them up with hydrolysis) Disaccharides – KEY FACTSDisaccharides are formed from two monosaccharidesglucose + glucose makes MALTOSEglucose + fructose makes SUCROSEglucose + galactose makes LACTOSEThe reaction that joins two monosaccharides is called a condensation reaction(break them up with hydrolysis)The bond formed between two monosaccharides is called a GLYCOSIDIC BOND – the number of the carbon atoms nearby that are joined gives the bond its name e.g. 1,4 glycosidic bond for maltose
25What are they? Macromolecules Polymers Made up of monosaccharide monomersCovalently bonded by Condensation Polymerisation
26Common ones Starch Glycogen Cellulose Chitin All made from glucose Different properties depend on which ISOMER and the type of GLYCOSIDIC bond
27Polysaccharide Monomer Glycosidic Bond Molecule Shape 1,4 Starchα-glucose(amylose)1,4Unbranched wound into a helix(amylopectin)1,4 with some 1,6Tightly packed branched chainGlycogen1,4 with more 1,6 than amylopectinVery branched compact moleculeCelluloseβ-glucoseUnbranched straight chains
28Starch Mixture of amylose (30%) and amylopectin (70%) Amylose: unbranched chains1,4 glycosidic bonds>300 glucose monomers, helical shapecoils have 6 monomers/turn held together by hydrogen bonds
29Starch Amylopectin: Glucose monomers 1,4 glycosidic bonded chains Branches in chains due to 1,6 glycosidic bondsBranches every residuesMolecule several 1000 monomers, very branched and coiled compactly
30Starch Functions as storage in plants: CompactInsolubleNo osmotic effectsDoesn’t interfere in cell reactionsEasily hydrolysed to sugars when requiredBuild up into grains in structures called amyloplasts in plant cytoplasm
31PolysaccharidesComplex carbohydrates – many monosaccharides joined together by glycosidic bondsIn plants strings of α-glucose joined by glycosidic bonds form starch, which is made up of amylose & amylopectinAmylase breaks the glycosidic bonds from the ends of amylose, and amylopectin (branched) which releases energy
32Glycogen Polymer of α-glucose with 1,4 and 1,6 glycosidic bonds Very similar to amylopectin but it branches more often, every 8 – 12 residues.Very compactEnergy storage in animals –liver and muscle cellsCytoplasm of bacteriaWell suited to its roleCompactRapidly hydrolysed to sugars when neededPage 6 of molecules handoutQuestion pack
33Cellulose Polymer of β-glucose 1,4 glycosidic bonds forming straight unbranched chains1000’s of monomersMajor constituent of the plant cell wall
40Chitin Chitin is used structurally HOMEWORK – find out more! Hand in a ‘fact sheet’ on ChitinMaximum of one side
41Polysaccharides – key facts Complex carbohydrates – many monosaccharides joined together by glycosidic bondsThey often fold-up on themselves to become more complex or are branchedThe body/plants uses polysaccharides as storage – these molecules can be broken down into smaller componentsBreaking glycisidic bonds is referred to as HYDROLYSIS and releases a lot of ENERGYPolysaccharides are INSOLUBLE so do not interfere with other chemical functions of the cell and have little impast on osmosisStarch is a polysaccharide found in plantsGlycogen is a polysaccharide found in animals
43Soluble in organic solvents (eg acetone, ether) Organic compoundsInsoluble in waterSoluble in organic solvents (eg acetone, ether)Relatively small(compared to polysaccharides)Tend to form together into globulesDue to not being soluble
44Naturally occurring fats and oils are esters Formed by condensation reactions between glycerol (an alcohol) and fatty acids+Fatty acidEsterGlycerol+3 H2O
45each can undergo condensation reaction with a fatty acid. H – C – C – C – HHOHGlycerolC3H8O33 hydroxyl groupseach can undergo condensation reaction with a fatty acid.Produces an ester called a triglyceride(triacylglycerol)
46Fatty AcidLong non-polar Hydrocarbon chain Polar carboxyl (COOH) end
48TriglyceridesTriglycerides containing saturated fatty acids have a high melting point and tend to be found in warm-blooded animals. At room temperature thay are solids (fats), e.g. butter, lard.Triglycerides containing unsaturated fatty acids have a low melting point and tend to be found in cold-blooded animals and plants. At room temperature they are liquids (oils), e.g. fish oil, vegetable oils.
49TriglyceridesThey are used for storage, insulation and protection in fatty tissue (or adipose tissue) found under the skin (sub-cutaneous) or surrounding organs.They yield more energy per unit mass than other compounds so are good for energy storage.Water released in oxidisation called metabolic water, important to organisms in dry climatesCarbohydrates can be mobilised more quickly, and glycogen is stored in muscles and liver for immediate energy requirements.
50PhospholipidsLike lipids, are esters of glycerol and fatty acids. BUT, one of the fatty acid chains is replaced by a polar phosphate group
52PhospholipidsPolar (phosphate) group is soluble in waterThe fatty acid chains are notSo at air-water or oil-water interfaces, phospholipids orientate so the polar head is in the water.Important constituent in cell membranes.
53Fats and health. Saturated or unsaturated? Which is best? What are the risks of the wrong type?How much is too much?Who says?What’s BMI?Question Pack