carbohydrates

Question 1

what groups do carbohydrates have

Answer 1

C=O and OH

Question 2

what are monosaccharides, oligosaccharides, and polysaccharides

Answer 2

mono: 1 unit of carb eg glucose. ketoses and aldehydes.
oligo: 2+ units of carb eg lactose
poly: 100+ units of carb eg cellulose

Question 3

how to calculate mirror images if a stereoisomer has multiple chiral carbons

Answer 3

4C = 2^4 = 16 stereoisomers = 8 mirror images

Question 4

what is an epimer

Answer 4

2 diastereoisomers with 1 different stereocentre

Question 5

what are pyranose and furanose forms

Answer 5

the cyclic forms of molecules where C=O turns into OH

pyranose has a 6 membered ring (5C 1O)
furanose has a 5 membered ring (4C 1O)

Question 6

what is the chair type structure

Answer 6

thermodynamically favourable structure for sugars in solution

Question 7

what are anomeric carbons

Answer 7

mutarotation - when sugars go into cyclic form c1 is chiral (after the oxygen) and anomeric.

anomers are designated α and β

α-anomer - OH group is on opposite side of CH2OH
β-anomer - OH group is on same side of CH2OH

Question 8

what are the types of products of oxidation with a weak oxidising agent

Answer 8

tollens, fehlings, benedicts solution used

turns aldehyde (sugar) into a carboxylic acid

Question 9

what are the types of products of oxidation with a strong oxdising agent

Answer 9

dilute nitric acid oxidises monosaccharide

produces a dicarboxylic acid eg glucaric acid

Question 10

what are types of products of oxidation with an enzyme system

Answer 10

oxidise aldose gives a uronic acid

uronic acid is a sugar acid

Question 11

what are esters

Answer 11

combinations of an acid and alcohol

components of dna and rna

cyclic monosaccharides and alcohol makes glycosides - in drugs and poisons in plants

Question 12

how is a disaccharide formed

Answer 12

2 cyclic monosaccharides undergo condensation of OH groups and form a glycosidic bond (bonded with O)

Question 13

what is a polysaccharide

Answer 13

multiple monosaccharides joined together via glycosidic bond

each bond is made with a different enzyme

can be heterogenous or homogenous, insoluble, hard to purify

Question 14

how to name polysaccharides

Answer 14

homo: replace ose with an eg glucan
hetero: structural main chain, prefixed with other units eg alginate (used for dental impressions)

Question 15

what is cellulose

Answer 15

a common glucan, makes plant cell walls

goes fibre - macrofibril - microfibril - chains of glucose