sugars Flashcards
what elements do all carbohydrates contain
C,H and O
what are the monomers that carbohydrates are made from
monosaccharides
what type of sugar is glucose
hexose
what’s a hexose sugar
a monosaccharide with six carbon atoms in each molecule
what are the two types of glucose
alpha and beta glucose
draw alpha glucose
alpha glucose has H on top and OH on the bottom
draw beta glucose
it has OH on the top and H on the bottom
how is a disaccharide formed
when two monosaccharides are joined together
how are monosaccharides joined together
condensation reaction
what bond forms between two monosaccharides
glyosidic bond
what monosaccharides make maltose
alpha glucose and alpha glucose
what monosaccharides make sucrose
glucose and fructose
what monosaccharides make lactose
glucose and galactose
what is the test you use to check for sugars
the benedict’s test
how do you check for reducing sugars
you add benedict’s regent to a sample and heat it in a water bath that’s been brought to the boil
how can you tell if the test is positive for a benedict’s test
a coloured precipitate will form and form a brick red colour
what is the order of colour that a positive test would show for a benedict’s test
green to yellow to orange to brick red
how can you tell which sample has the highest amount of reducing sugar
filter the solution and weigh the precipitate OR remove the precipitate and use a colorimeter to measure the absorbance of the remaining benedict’s solution
how do you test for non-reducing sugars
if the reducing test is negative get a new sample of the test solution, add dilute hydrochloric acid, carefully heat it in a water bath that’s been brought to the boil, then neutralise it by adding sodium hydrogencarbonate and carry out the reducing sugar test
what’s a negative result for benedict’s test
blue
what is a reducing sugars test testing for
maltose, lactose, monosaccharides
what is a non reducing test testing for
sucrose
