food is made up of 14 elements , carbon, hydrogen, oxygen, and the rest are
often called minerals
carbohydrates
monosacharides
discharides
polysacharrides
source: bread, potatoes, rice, flour and sweets
made up of carbon, hydrogen and oxygen
structure:amino acids, peptides, poly peptides and protein
proteins contain the elements carbon, hydrogen
,oxygen and nitrogen
sometimes small amounts of sulfur and
some may contain small bits of
phosphorus
sources: meat,fish,eggs,milk
proteins
metabolic role: proteins are used as ensymyes to control reactions ,they also form
antibodies to fight infection. some hormones are protein-based and are used to regulate
body reactions
test: sodium hydroxide , then copper sulfate (biuret test)
help to form structures such as skin, hair, nails,
and muscles
minerals
plants need calcium to hold the cell wall together, and magnesium for chlorophyll
animals need calcium for bones and teeth and iron for haemoglobin
lipid
the molecules of a lipid are made up of a glycerol molecule and 3
fatty acid molecules
fats solid at room tempeture
oils liquid at room tempeture
phospholipids- used to make up cell
membrane & is critical for the function of cells
vitamins
vitamin c
water soluble ,
source:veg,fresh fruit.
metabolic role: forms
connective tissue ,bones
+teeth. helps healing and
immune system.
deficiency: scurvy(poor
skin,bleeding gums,bad
teeth
vitamin d
fat-soluble
source:liver,fish oils
,milk, made in skin.
metabolic role: helps
absorb calcium for
teeth and bones.
deficiency : rickets in
children, osteomalacia
in adults
food tests:
rub a piece of butter(fat) and a
drop of water on brown paper. fat
is present in butter, brown paper
turns translusent
starch: brick-red to blue black. (iodine solution)