carbohydrates Flashcards
what elements do carbohydrates contain?
carbon
hydrogen
oxygen
what are the monomers of carbohydrates?
monosaccharides
what is an isomer?
molecules with the same molecular formula as each other but with the atoms connected in a different way
what is a disaccharide?
when 2 monosaccharides are joined together by a condensation reaction
what bond forms between the 2 monosaccharides?
glycosidic
name some examples of disaccharides
sucrose
lactose
maltose
how is sucrose formed?
glucose and fructose
how is lactose formed?
glucose and galactose
how is maltose formed?
glucose and glucose
what is the benedicts test for reducing sugar?
add benedicts
and heat
blue = no reducing sugar
green - yellow= reducing sugar present
what is the benedicts test for non reducing sugars?
heat a new sample with dilute hydrochloric acid and neutralise by adding sodium hydrogencarbonate then heat with benedicts
blue = no non reducing sugar
green - red = non reducing sugar present
What are polysaccharides?
2 or more monosaccharides joined together
What is starch?
Excess glucose in plants
2 types - amylose ( long, unbranched chain of alpha glucose)
Amylopectin ( long, branched chain of alpha glucose)
Insoluble in water
What is glycogen?
Excess glucose in animals
lots of side branches
compact so good for storage
What is cellulose?
long
unbranched
beta glucose
form microfibrils
plants cell walls
