Nutrients

1Carbohydrates should be 55-60% of energy

Plants by photosynthesis(monosaccharide-glucose,disac malt-lact-sucrose)

Starch-main food reserve,2 types of glucose polymer-amylose linear+amylopectin-branched

Cellulose-10k glucose units

2Fats 30%-lipids,glycerol esters

Essential-linoleic,linolenic,unsaturated

It dissolves vitamins,protects thermally&physically

Hydrogenating with Ni cat.180C,H2 bubbled through,makes harder&stable

3Proteins 10-15%

aPrimary structure-amino acids linked by peptide bonds,8 essential

bSecondary structure-a-helix with H-bonds

cTertiary structure

iFibrous-insoluble in H2O,resistant to pH+t

AElastic-mycosine(muscle),wool

Binelastic-cross links,e.g.fibrin(collagen)

iiGlobular-soluble,affected by pH,e.g.egg albumin,casein,gelatine

Functions-structure(collagen in bones),food store(albumen),oxygen carrier,enzymes,buffers

Enzymes-destroyed on heating,inactive in extreme pH

4Mineral elements

aPart of body structure(CA in bones)

bFluids in the tissues,buffers

cComponent of enzymes

5Water-60%

aTransport nutrients

bTake part in chemical changes in the tissues&during digestion

cMaintains tissue rigidity

6Vitamins

RetinolA,nicotinic acidB,thiaminB1,riboflavinB2,Ascorbic acidC,cholecalciferolD,TocopherolE,K

AEnergy supply-CFP

BGrowth&repair of body-PMW

CControl of body processes-PMWV

Body needs oxygen&energy,of basal metabolism 6700kJ/day

Glucose content-0.5% glucose soln to burette

225cm3 Benedichts to wide-mouth conical flask,Add anhydrous Na2CO3+ boiling stones

4Heat until NaCO3 dissolves

5Titrate first rapidly then drop per 20sec until blue colour disappears,solution must boil,1%methylene blue as indicator

6Repeat with liquid you want

Glucose is a reducing sugar&Benedichts reagent tests for organic reducing agents

To measure sucrose we must boil with HCl for a while to convert sucrose to glucose

Vitamin C in cabbage

Istandardise indicator DCPIP

0.04% DCPIP(0.4gdm-3) to burette, 25cm3 C to wide-mouth conical flask,blue colour of the dye turns colourless because of C,when finished turns red(10sec)because acidic cond

3Subtract Blank titration 25cm H3PO4

IIuncooked cabbage

1Liquidize 50g with 5% H3PO4(inactivates enzyme&dissolves C better&does not destroy it

2Titrate

IIIcooked cabbage

1Simmer 50g in little water to avoid loss,but more C is destroyed,because enzyme is not destroyed fast enough)