L E A R N IN G• To O U theCelementsEin state T OM S lipids.• To state the main types of lipids.• To state the components of fats & oils.• To explain the formation & breakdown of fats & oils.• To compare & contrast saturated fats & unsaturated fats.
• E le m e nts : C , H & O• Typ e s of lip id s : fats, oils, waxes, phospholipids, steroids (cholesterol, testosterone, oestrogen, progesterone)• F ats & oils are p lace d in a cate gory calle d triglycerides.• 3 cate gorie s of lip id s : monoglycerides, diglycerides, triglycerides
• Fats solid in room temperature (high melting point)• Oils liquid in room temperature (lower melting point)• Triglyceride made up of one glycerol & 3 fatty acids.
• 1 Glycerol + 1 fatty acid monoglyceride + 1 water• 1 Glycerol + 2 fatty acids diglyceride + 2 water• 1 Glyceride + 3 fatty acids triglyceride + 3 water• The formation of fats & oils involves the reaction of condensation between glycerol & fatty acids
• In the presence of enzymes, three fatty acids become covalently bonded to one glycerol & produces 3 molecules of water.• The breakdown of fats & oils hydrolysis + enzymes glycerol & fatty acids.
S A TU R A TE D &U N S A TU R A TE D F A TS • Saturated fats : contain saturated fatty acids (do not have any double bond between the carbon atoms) SOLID FORM AT ROOM TEMPERATURE, 27OC (butter) • Unsaturated fats : contain unsaturated fatty acids (at least one double bond between the carbon atoms) LIQUID FORM AT ROOM TEMPERATURE, 27OC (corn oil, palm oil)
COMPARISONS A TU R A TE D F A T U N S A TU R A TE D S IM ILAR ITIE S F A T BO TH are triglyce rid e & contain fatty acid s . d iffe re nce s C ontain s atu rate d fatty acid C ontain u ns atu rate d fatty acidIts C arb on ch ain contains m ax. Its carb on ch ain is not nu m . of h yd roge n s atu rate d with h yd roge n. S ingle b ond b e twe e n carb on At le as t 1 D ou b le b ond atom s b e twe e n carb on atom s (-c-c-) (-c= c-)
COMPARISON (cont.) d iffe re nce sS olid at room te m p e ratu re Liqu id at room te m p e ratu re H igh m e lting p oint Low m e lting p oint Incre as e th e le ve l of D e cre as e th e le ve l of ch ole s te rol in th e b lood ch ole s te rol in th e b lood Incre as e th e ris k of h e art D oe s not incre as e th e ris k of d is e as e s h e art d is e as e sE xam p le : anim al fats (lard , E xam p le : ve ge tab le oils b u tte r) (p alm oil, corn oil)