medchem 24,25,26

Question 1

— 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

Answer 1

monosachirdes as glucose and fructose

Question 2

aldose ( has 4 chiral centres ) and ketone ( has three chiral centres ) are —

Answer 2

structural isomers

Question 3

L in notation refers to the OH in the —
and D is in the —

Answer 3

left side
right side

Question 4

howorth presents the – form of glucose which is more common than Fischer

Answer 4

cyclic ( pyranose structure ) for monosaccharide in 3d view

Question 5

point the hydroxyl group down if they are in —-
point them up if they are —
if its D —
if its L –

Answer 5

right , left
up, down

Question 6

when new chiral centre is created at the hemiacteal carbon in c1 we call it

Answer 6

anometric carbon and during the cyclisation 2 different diasmersis will form (beta and alpha )

Question 7

the conversion of alpha and beta anomirs is called

Answer 7

mutarutation
( alpha and beta are stable solids but in liquids they are quickly to equilibrate and form 2 forms )

Question 8

why’s is b-D glucose more favourable than alpha ?

Answer 8

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

Question 9

equatorial is — ( sides)
axail in —- ( up or down )
( chair conformation )

Answer 9

beta , alpha

Question 10

cu +2 îs — and the color is –
cu + îs —- and the color is –
this test is a Benedict reagent and is for —

Answer 10

blue , oxidised
red , redcued and it precipitates
reducing agents ( only aldehydes are reduces ketons aren’t )

Question 11

which of these are stable:
acetal or hemiacetal

Answer 11

acetals are stable but hemiatals can be opened and is reversible

Question 12

maltose is —–
and what reaction can it undergo –

Answer 12

alpha 1-4 glycosidic linkage came from beta and alpha
mutarotation ( bc it has aldehyde )
and reducing sugar

Question 13

collibos is —

Answer 13

beta 1-4 glycosidic linkage
came from beta and beta and can undergo mutarotatoon and reducing agent

Question 14

lactose is from —
and is —-

Answer 14

glucose and galactose found in human and cows milk
beta 1-4 glycoside linkage

Question 15

lactose intolerance came from

Answer 15

• 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

Question 16

– 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

Answer 16

galagtosemia
( galagos is being build up in the urine and blood which will be reduced to galacitiol )

Question 17

sucrose is formed by —- and is —

Answer 17

glucose and fructose
alpha and beta ( bc we used both aneormric carbon) 1-2 glycoside linkage from alpha and beta

Question 18

— cant undergo mutarotaion or reducing agent

Answer 18

sucrose
bc of hemiacteal so it cant open and form an aldehyde and cant be reduced

Question 19

sucrose can be broken down by — which produces — leading to —–

Answer 19

• 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

Question 20

carbohydrate have —–

Answer 20

aldhyedes/ketons and alcohol groups

Question 21

aldoses/ketose ( monoacide ) can form — by —
hemicactel can react with alcohol from another monosacride to produce —

Answer 21

• hemiacetals/hemiketals by cyclisation
• discacride aka acetals

Question 22

purification of hemiactelas and hemiketals by — because they are unstable and need to maintain quiliqbum and be constant

Answer 22

• removing alcohol

Question 23

hemactela groups can undergo —
hemiketal groups can undergo
actetal and ketal groups undergo –

Answer 23

• mutarotaion and reducing agent
• mutarotaion only bc ketons cant be oxidised
• nothing as: sucrose which contain ketal group

Question 24

strach is made up of 2 of — which are —

Answer 24

• 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

Question 25

the structural component of plants cell walls – and contains —

Answer 25

callous ,beta 1-4
its a straight chain of polymer b glucose
300-26,000 length

Question 26

cellulose can become cellobise by — enzyme and then d - glucose

Answer 26

cellulas which beta 1-4 and humans don’t have this enzyme

Question 27

major glucose storage molecule of animals and is found in the liver and ,muscle

Answer 27

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

Question 28

glucose becomes glycogen by —
and glycogen becomes glucose by –

Answer 28

insulin , glucagon