Boilogical molecules and food tests

carbohydrates

can be simple sugars or complex starch

proteins

needed for growth, made of single units amino acids

lipids

store energy, are made up of glycerol and fatty acids

Fibre

not digested, used to help move food throughout the intestines

Carbohydrates (chemical composition)

carbon, hydrogen, oxygen

monosaccharides

glucose, fructose, galactose

disaccharide (maltose)

glucose and glucose

disaccharide (sucrose)

glucose and fructose

disaccharide( lactose)

glucose and galactose

polysaccharides

starch, glycogen

Protein (chemical composition)

carbon, hydrogen, oxygen, nitrogen

Lipids (chemical composition)

carbon, hydrogen, oxygen

Forms of lipids

fats and oil

Lipids structure

glycerol with fatty acids chains

Test for starch

add iodine, dark brown→purple if positive

Test for protein

add Biurets, light blue→light purple if positive

Test for glucose

add benedict’s and heat in hot water for 2 mins, blue→ orange if positive

Test for lipids

add Ethanol and shake, add equal amount of water, clear→ cloudy if positive