CARBOHYDRATES Flashcards
carbohydrates
molecules containg CHO
are sugars
taste sweet
soluble in water
monosaccharides
simplest carbohydrate
e.g:
a-glucose
b-glucose
ribose
deoxyribose
alpha glucose
OH at bottom right
C6H12O6
energy source
component of starch and glycogen (energy stores)
beta glucose
OH at top right
energy source
component of cellulose (plant cell wall)
ribose
pentose sugar
component of RNA and ATP
deoxyribose
pentose sugar
component of DNA
Disaccharides
two monosaccharides bonded together by a glycosidic bond
a-glucose + a-glucose
maltose + water
bonded by alpha 1-4 glycosidic linkage
a-glucose + fructose
sucrose
bonded by alpha 1-2 glycosidic link
B-galactose + a-glucose
lactose
bonded by beta 1-4 glycosidic link
B-glucose + B-glucose
cellobiose
beta 1-4 link
polysaccharide
many sugar chains bonded together
homopolysaccharide
polysachharide made of the same monosaccharide
heteropolysaccharide
polysaccharide made of diff monomers
carbs as energy source
glucose releases energy to form ATP
carbs as energy store
glycogen in animals
starch in plants (amylose, amylopectin)
glycogen
alpha 1-4, alpha 1-6 glycosidic bonds
energy store
coils so compact (stores lots of energy)
insoluble so no affect on water potential
branched so easily hydrolysed for energy
amylopectin
1-4,1-6 alpha glycosidic bonds
branched so hydrolysed for energy easily
coiled so stored lots of energy
insoluble
amylose
1-4 alpha glycosidic bonds
unbranched
insoluble
coils so stores lots of energy
cellulose
polysaccharide of beta glucose
every other b-glucose is inverted by 180degrees so h and oh can bond
cellulose chains are straight due to h bonds between straight chains
cellulose form microfibrils which form macrofibrils
plant cell wall
structure and function
macrofibrils have high tensile strength due to h bonds between chains
macrofibrils run in all directions cris-crossing for extra strength when turgid
cell walls are fully permeable for water to enter
chitin
exoskeleton
fungi cell wall
long parallel chains of acetylglucosamine
peptidoglycan
bacterial cell wall
polysaccharide uses practical
cellophane
paper
cotton
reducing sugars
maltose
lactose
non reducing sugars
sucrose
test for reducing sugars
add benedicts to sample
put in hot water bath
goes from blue to brick red
test for nonreducing sugars
add equal parts HCL to sample
boil solution in water bath for 5 min
add NaOH to solution
add benedicts
and heat in water bath for 5 min
blue to brick red
