nutrition Flashcards
functions of water
- a solvent for many chemical reactions
- medium for chemical reactions
- needed for hydrolysis
- plays a role in regulation of body temperature in warm blooded animals
- trasnport dissolved substances around the body
- key component of various fluids in body
carbohydrates made of?
- carbon, hydrogen, oxygen
- presence of oxygen and hydrogen 1:2
simple suagrs
- monosaccharides
- glucose
- fructose
- galactose - disaccharide
- maltose
- sucrose
- lactose
complex carbohydrates
- polysaccharides
- starch
- glycogen
- cellulose
monosaccharide characteristics
- C6H12O6
- can pass throguh cell membrane
- further broken down to release energy
- glucose: in animals and plants
- fructose: in animals
- galactose: present in milk sugars in mammals - diff arrangement of atoms
disaccharide charateristics
- formed by condensation of two monosaccharide moleculs
- same chemical formula of C12H22O11
- diff arrangement of atoms
glucose + glucose -> maltose + water
hydrolysis meaning and example
cemical reaction to chemically break down a complex substance to form a simple substace, it requires one molecule of water
maltose + water -> glucose + glucose
reducing suagrs
all carbohydrates are reducing sugars EXCEPT SUCROSE
polysaccharides characteristics
many condensed monosaccharides cehmically combined together
starch: plant storage organs
cellulose: plants
glycogen: liver and musles of mammals
they are all made of glucose molecules w diff arrangements
fats made up of?
carbon hydrogen oxygen
less oxygen than hydrogen
proporation of elements are not fixed
fats charateristics
one glycerol molecule and 3 fatty acids chains
insoluble in water
soluble in organic solvents
hydrolysis of fats
fats + 3H20 -> one glycerol + three fatty acids molecules
proteins made up of ?
carbon hydrogen nitrogen oxygen
may contain sulfur and phosphorus
formation of proteins
amino acids are linked up by peptide bonds to form a polypeptide
2 or more polypeptide chains fold to form a protein
uses of proteins
- synthesis of new protoplasm
- make antibodies
- make enzymes
- make hormones
- last source of energy in body
Benedict’s test
for reducing sugar
- add 2cm3 of Benedict’s solution into 2cm3 of sample and shake
- place into boiling water bath
brick-red precipitate forms -> high conc of RS present
mixture remains blue -> no reducing suagr present
Biuret’s test
test for proteins
- add 2cm3 of sample into 2cm3 of aqueous sodium hydroxide
- shake
- add 1% of copper (II) sulfate solution drop by drop, shaking ater each drop
violet colouration seen -> prteins present
no violet colouration seen -> no proteins
iodinetest
test for starch
place sample onto a white tile
add a few drops of iodine
turns blue black if got starch
remians yellowish brown if there is no starch
ethanol emulsion test
test for fats
to 2cm3 of sample, add2cm3 of ethanol
shake
add water to mixture
white emulcion->fat present
no white emulsion -> no fats present
how tondo food tests for SOLID subs
cut into smaller pieces
place into test tube and add xxcm3 of water
shake
decant mixture into new test tube
-> pouring liquid portion of oxyture and leaving behind solid sample