Sugars

Question 1

three types of carbohydrates

Answer 1

monosaccharide, disaccharide, polysaccharide

Question 2

diff between carbohydrate vs erythritol

Answer 2

CnH2nOn vs CnH2n+2On

erythritol has 2 more hydrogens than carbohydrate

Question 3

nomenclatur in carbons is based on . . .

Answer 3

of carbons and functionality (aldose vs. ketose)

Question 4

3 in # of carbons

Answer 4

triose

Question 5

4 in # of carbons

Answer 5

tetrose

Question 6

5 in # of carbons

Answer 6

pentose

Question 7

6 in # of carbons

Answer 7

hexose

Question 8

7 in # of carbons

Answer 8

heptose

Question 9

What’s the difference between aldose and ketose functionality in carbohydrates?

Answer 9

H O
\ //
C
aldehyde functionality

C = O
ketone functionality

Question 10

difference between epimers and anomers

Answer 10

anomers are epimers.

epimer - 2 sugars differ in configuration around one carbon

anomer - carbon in cyclic sugar that is the carbonyl C, C = O, in the open-chained (acyclic) form

Question 11

enantiomer

Answer 11

stereoisomers that’re mirror images

Question 12

diastereomers

Answer 12

stereoisomers that aren’t NOT mirror images (have diff physical properties)

Question 13

anomer

Answer 13

epimers differ at hemiacetal/acetal carbon

Question 14

epimer

Answer 14

2 sugars differ in configuration around one carbon

Question 15

in chair conformation, which is more stable? why?

Answer 15

beta because molecules are further apart than alpha configuration so energy is more stable.

Question 16

mutarotation

Answer 16

interconversion of alpha- and beta- anomers

Question 17

tests that detect reducing sugars

Answer 17

Tollen’s Test and Benedict’s Test

Question 18

What is Tollen’s Test?

Answer 18

aldehyde can reduce Ag+ and Ag0

Question 19

What is Benedict’s Test?

Answer 19

aldehyde can reduce Cu2+ (cupric) to Cu+ (cuprous)

red = reducing
blue = non-reducing

Question 20

How does fructose become a reducing sugar?

Answer 20

fructose goes through a process called tautomerization where it converts into aldohexose. This has an aldehyde which passes as a reducing sugar in the Benedict’s Test.

Question 21

what is a disaccharide?

Answer 21

when 2 sugar molecules are joined via glycosidic bond between anomeric caron and hydroxyl oxygen

Question 22

at what carbon positions can glycosidic bond in a sugar molecule?

Answer 22

1’, 4’, 6’

Question 23

When a glycosidic bond is bonded where both sugars are bonded at the 1’ postition, is it a reducing or non-reducing sugar?

Answer 23

non-reducing sugar

Question 24

traits of homopolysaccharide

Answer 24

linear or branched

Question 25

traits of heterosacchride

Answer 25

consists of two monomers, it is unbranched consists of multiple monomers, it is branched

Question 26

do polysaccharides have a defined molecular weight?

Answer 26

no because there are no templates used to make polysaccharides

Question 27

what are the 2 plant polysaccharides?

Answer 27

amylose and amylopectin

Question 28

types of polysaccharides

Answer 28

amylose, amylopectin, glycogen, cellulose, chitin

Question 29

traits in amylose

Answer 29

homo, (alpha 1,4) Glc, linear

Question 30

traits in amylopectin

Answer 30

homo, (alpha 1,4) Glc with (alpha 1,6) branches 24-30 residues

Question 31

traits in glycogen

Answer 31

homo, (alpha 1, 4) Glc with (alpha 1, 6) Glc branches 8-12 residues energy storage in bacteria and animals

Question 32

traits in cellulose

Answer 32

homo, (beta 1, 4) Glc structural (in plants); gives rigidity and strength to cell walls

Question 33

traits in chitin

Answer 33

homo, (beta 1, 4) GalNAc (aka galactose) structural (in insects, spiders, and crustaseans); gives rigidity + strength to exoskeleton

Question 34

What's a proteoglycan?

Answer 34

glycoproteins that're heavily glycosylated

Question 35

What is proteoglycan used for?

Answer 35

it is used in the animal extracellular matrix where it's used between cells to signal molecules

Question 36

glycoprotein

Answer 36

protein with small oligosaccharides attached

Question 37

how can carbohydrates be attached?

Answer 37

they are attached throught the anomeric carbon

Question 38

what does linked (like o-linked and n-linked) proteins do?

Answer 38

it shows how the sugar is attached to the protein

Question 39

O-linked glycoprotein

Answer 39

anomeric carbon attached to amino acid with 'OH' group like Serine and Threonine

Question 40

N-linked in glycoprotein

Answer 40

anomeric carbon attached to amino acid Asparagine

Question 41

in a sugar bond , beta and alpha are in what direction?

Answer 41

beta = up & alpha = down

Question 42

acetal in regards to a sugar bond means . . .

Answer 42

the sugar is reduced to its final form

Question 43

why is atom numbering important?

Answer 43

it can be different based on open vs cyclic form

Question 44

furanose

Answer 44

five member close chain form of monosacchride

Question 45

pyranose

Answer 45

six member close chain form of monosacchride

Question 46

3 carbon aldose

Answer 46

Glyceraldehyde

Question 47

5 carbon aldose

Answer 47

Ribose

Question 48

6 carbon aldose (and know open-ring conformation)

Answer 48

Glucose, Mannose, Galactose

Question 49

6 ring carbon (and know open-ring conformation)

Answer 49

Fructose

Question 50

Are alehyde and ketone carbons are electrophillic or nucleophillic?

Answer 50

electrophillic

Question 51

Is alcohol oxygen atom electrophillic or nucleophillic?

Answer 51

nucleophillic

Question 52

in anomers, alpha-mutarotation hydrogen is on top while hydroxyl is on the bottom whereas . . .

Answer 52

For beta conformation, this is the opposite.

Question 53

how does a glycosidic bond work?

Answer 53

this is when there are two sugar molecules that bond at the anomeric carbon and the other is the 1', 4', or 6' position. the sugars bond at the hemiacetal and H and HO connect to perform hydrolysis. After bonding, the sugars are in acetal form where it is reduced to its final form