Direct Dr.Nagwan Gabr& Dr. Nihal Gabr 4 January 2015 Code: WBI01/01 Paper 1 1A. 4. Lipids 2. Lipids such as triglycerides and polysaccharides such as glycogen are energy storage ‘molecules. These molecules can be used during exercise. {a) Triglycerides are a type of lipid formed when three fatty acid chains combine with a glycerol molecule. (0 Puta cross in the box that completes the following statement. Each fatty acid chain is joined to glycerol by WA. anester bond formed by a condensation reaction [2B anester bond formed during hydrolysis (._ € peptide bond formed by a condensation reaction o D_ apeptide bond formed during hydrolysis (i Describe how the structure of a saturated lipid differs from that of an unsaturated lipid Sclucused Ciprds have No C= and No bile More YR 4 © fake Gn Seat ones 1A. 3. Carbohydrates 2 (2) (b) Describe the structure of gyeagen._. ie TS rade fron alien Syntace ons, Cantoaniay FM and 1 6 gnrondic_bond. ik is benched1A.4. Fats (yb Dit Gil) St how tt ide tr rted in the blood. (i) Suggest how triglycerides are transported in the 7 Aeiqryectd on insoluble in waker to Ley bind 4 proteins. fecaaigy. LDL and HDL and fora _micettea 7 May 2016 Code: WBI01/01 Paper 1 1A.4. Lipids 1. Triglycerides are synthesised from glycerol and fatty acids. {a) The diagrams below show the structures of three fatty acids and their melting . OH aacestee BN N. Ht linolenic acid -5°C 5 J CNN {Using the diagrams above, describe the structite of oleic aci “ke A CRC tlowe bend anh a IIS Qu COOH) _ i Mone WUnsatu aitoh.i) Using the information in the diagrams, explain why these fatty acids have different melting temperatures. ———__ a C=C dovlole neds ere Caner 9 sail OT Sa Brey Ware on Lorser relki§ Comperalis® As wep os Redoute toreds Cauza _ Rre Gable, auack clrotiey 40 be Farrer oport _Inene Inawigs _vsendA e¢ intecwoteubux ola liars. fx OY (b) The diagrams below show the simplified structures of a fatty acid molecule and a ‘lycerol molecule. 0, fattyacid Se Ho iH ‘alycerol ‘OH (i). Use these diagrams to show the products formed from a reaction between ‘one fatty acid molecule and the glycerol molecule. & | 9-U A NN 2 pol oOo +O amie (il) Name this type of reaction. o Dr.Nagwan Gabr& Dr. Nihal Gabr nie6 Trighcerides are synthesised from fatty acids and glycerol ‘One of the reactions involved in the synthesis of triglycerides is shown below. diglyceride fatty acid (21 Diglycerde acytransferase (DGAT) isthe enzyme that completes the synthesis of a triglyceride by joining a fatty acid onto a digyceide. (Name the bond that links fatty acids to glycerol. ORAL a - i. Which ofthe following arrangements of atoms links a glycerol molecule to a fatty acid? ——<—0—[ “hydrocarbon chain DB —c-c-o-[ hydrocarbon chain DB ¢ —c-o-C{ hydrocarbon chain W _ —c-0-C| hydrocarbon chain(ii Fatty acids can be saturated or unsaturated. Distinguish between the structure of a saturated fatty acid and the structure of an unsaturated fatty acid. 2) Unoaturated fatty vide have a Carbon carbon double bond foering kinks while suturated fatty acide do rot at they have a carbon carbon single bond 9 May2017 4 The addition of sugars to food i one isk factor for cardiovascular disease (CVD) {@) Two sources of sugar used in foods are sucrose and high fructose com syrup. (0) Describe how sucrose i formed from monosaccharides. formakion a Vo shysondie es be. cankgatakion — teackt on xe Pactose ont Ancore- 1A.3. Carbohydrates 2 @ (i High ructose com syrup is manufactured for starch. Descrbo the structure of starch, Sharda Tw Made uP froe~ amie ands emanepentin fran Neha SMactye cele Omnis 1 led adele osmlopetice 3S loranthed- Dr.Nagwan Gabr& Dr. Nihal Gabr osDirect 14.3. Carbohydrates 2: Polysaccharides 8 Glucose is stored in muscle cells as glycogen. (2) Describe how glycogen is formed from glucose. » Coons, abacore wntey apc Ayethe formans, me Yryosiebic land by Condeyation Teuction velire Gout Cerrreds end \ju_and. 16 Wcgidas._. tondla _feosa-chenve Bs Leger 1K lerantred 2 (b) Explain why energy is stored in the form of glycogen in muscle cells. 2) oe Vw aes as 5h down + en Spars and. Con he “a tok_s S¢ Sond io thre_.cell. Mso ib aah oPpetk esmobic (esse Ot iA iMolubie ond ts ONreart ve - Dr.Nagwan Gabr& Dr. Nihal Gabr 0301A.4. Lipids 4 Human diets contain both saturated and unsaturated lipids. (a) Give two differences between the structures of saturated and unsaturated lipids. 1 Golaraked Grids wre no mle wile ansotusaked pds nara leis i nksutedcesds Bethy rove Weer Cotd0on- Ra LAS oe Edn on 12 October 2018 i Tad Carboni me dass