medchem 24,25,26 Flashcards
— a sugar consisting of a single ring shape and is a poly hydroxy ketone or aldehyde and the formula is cn (h20)n where n>3
monosachirdes as glucose and fructose
aldose ( has 4 chiral centres ) and ketone ( has three chiral centres ) are —
structural isomers
L in notation refers to the OH in the —
and D is in the —
left side
right side
howorth presents the – form of glucose which is more common than Fischer
cyclic ( pyranose structure ) for monosaccharide in 3d view
point the hydroxyl group down if they are in —-
point them up if they are —
if its D —
if its L –
right , left
up, down
when new chiral centre is created at the hemiacteal carbon in c1 we call it
anometric carbon and during the cyclisation 2 different diasmersis will form (beta and alpha )
the conversion of alpha and beta anomirs is called
mutarutation
( alpha and beta are stable solids but in liquids they are quickly to equilibrate and form 2 forms )
why’s is b-D glucose more favourable than alpha ?
bc the reaction is reversible ( so beta can form and then open again ) , the arrangement of the hydroxy group in nature as well as more room is found in the beta while the alpha is crowded
equatorial is — ( sides)
axail in —- ( up or down )
( chair conformation )
beta , alpha
cu +2 îs — and the color is –
cu + îs —- and the color is –
this test is a Benedict reagent and is for —
blue , oxidised
red , redcued and it precipitates
reducing agents ( only aldehydes are reduces ketons aren’t )
which of these are stable:
acetal or hemiacetal
acetals are stable but hemiatals can be opened and is reversible
maltose is —–
and what reaction can it undergo –
alpha 1-4 glycosidic linkage came from beta and alpha
mutarotation ( bc it has aldehyde )
and reducing sugar
collibos is —
beta 1-4 glycosidic linkage
came from beta and beta and can undergo mutarotatoon and reducing agent
lactose is from —
and is —-
glucose and galactose found in human and cows milk
beta 1-4 glycoside linkage
lactose intolerance came from
- lactose digestion is in the small intestine and the enzyme lactase breaks down lactose into glucose and galactose so in lactose intolerance we will have low levels of lactase which leads to build up of lactose in the small intestine and will lead to baceterial termination and produce c02 and h2 which causes irritation
– a genetic metabolic disease which leads to the defect in the body’s ability to use the sugar in galactose and the defect in the enzyme GALT ( galactose -1- phosphate uridyl transefrase ) which causes acuumealtion of galactose 1 phosphate and damages the liver kidney and brain and is more serious than lactose intolerance
galagtosemia
( galagos is being build up in the urine and blood which will be reduced to galacitiol )
sucrose is formed by —- and is —
glucose and fructose
alpha and beta ( bc we used both aneormric carbon) 1-2 glycoside linkage from alpha and beta
— cant undergo mutarotaion or reducing agent
sucrose
bc of hemiacteal so it cant open and form an aldehyde and cant be reduced
sucrose can be broken down by — which produces — leading to —–
- glycosl
- fructose and glucose
- glucose gives dextran which is not soluble in water and fructose gives lactic acid
- bacteria and lactic acid will be embedded in the dextran and prodcue plaque and the lactic acid will dissolve the ca_2 in the tooth enamel
carbohydrate have —–
aldhyedes/ketons and alcohol groups
aldoses/ketose ( monoacide ) can form — by —
hemicactel can react with alcohol from another monosacride to produce —
- hemiacetals/hemiketals by cyclisation
- discacride aka acetals
purification of hemiactelas and hemiketals by — because they are unstable and need to maintain quiliqbum and be constant
- removing alcohol
hemactela groups can undergo —
hemiketal groups can undergo
actetal and ketal groups undergo –
- mutarotaion and reducing agent
- mutarotaion only bc ketons cant be oxidised
- nothing as: sucrose which contain ketal group
strach is made up of 2 of — which are —
- glucose
- amylose ( 20%) , 200-2000 alpha d glucsoe
- amylopectin ( 80%) m 300-5000 alpha with 20 units chains branching off and is highly branched, it has:
- branched point: alpha 1-6 and the glycosidic linkage is alpha 1-4 , so it has liner and branched
the structural component of plants cell walls – and contains —
callous ,beta 1-4
its a straight chain of polymer b glucose
300-26,000 length
cellulose can become cellobise by — enzyme and then d - glucose
cellulas which beta 1-4 and humans don’t have this enzyme
major glucose storage molecule of animals and is found in the liver and ,muscle
glycogen : branched is alpha 1-6 and glycoside linkage is alpha 1-4 it has similar structure to amyloptin but is shorter and occur more frequently in glycogen
glucose becomes glycogen by —
and glycogen becomes glucose by –
insulin , glucagon
