module 7: Carbohydrates

Question 1

how to calculate stereoisomers in chiral carbons?

Answer 1

2^n stereoisomers
example) 4 chiral carbons= 2^4=16 stereoisomers

Question 2

what is the empirical formula of carbohydrates?

Answer 2

(CH2OH)n

Question 3

what carbohydrates tend to be cyclized?

Answer 3

long carbohydrates (5+ )

Question 4

what is the result of the formation of cyclized structures?

Answer 4

reaction of internal alcohol group with either a aldehyde or ketone

Question 5

what does an aldehyde + hydroxyl group form?

Answer 5

hemiacetal

Question 6

what does a ketone + hydroxyl group form?

Answer 6

hemiketal

Question 7

what is pyran ring?

Answer 7

6 membered sugar

Question 8

what is a furan ring?

Answer 8

5 membered sugar

Question 9

what does the cyclization of glucose involve?

Answer 9

C5 hydroxyl & C1 aldehyde

Question 10

how many stereoisomers does cyclization produce?

Answer 10

2

Question 11

what are anomeric carbons?

Answer 11

the carbon that becomes chiral as a result of cyclization

Question 12

is A-hydroxyl of anomeric carbon above or below plane of sugar?

Answer 12

below

Question 13

what is mutatoration?

Answer 13

interconversion of alpha and beta forms of a sugar

Question 14

cyclization of fructose into fructofuranose involves which hydroxyl carbon & which carbonyl carbon?

Answer 14

C5 hydroxyl and C2 ketone

Question 15

does fructose exist in both pryan & furan rings?

Answer 15

yes

Question 16

what B-fructopyranse sweet or salty?

Answer 16

sweet

Question 17

what are the 3 sugar derivatives?

Answer 17

nitrogen, phosphate & sulphur

Question 18

what do reducing agents do?

Answer 18

defines the end of the sugar with the carbonyl carbon as being the reducing end

Question 19

what is a glycosidic bond?

Answer 19

primary structural linkage in all polymers of monosaccharides

Question 20

what is the reducing end?

Answer 20

pre-anomeric carbon at end of polymer

Question 21

higher order carbohydrate structures are generated through…

Answer 21

glycosyltransferases

Question 22

glycosyltransferases use ( ) that are activated through linkage with ( )

Answer 22

monosaccharides, UDP

Question 23

what suffix does the non-reducing sugar have?

Answer 23

osyl

Question 24

what suffix does the reducing sugar have?

Answer 24

ose

Question 25

Maltose links ( ) from beta to ( ) to of alpha

Answer 25

C4 - C1

Question 26

what is the condensation reaction?

Answer 26

release of a water molecule

Question 27

what is lactose made of?

Answer 27

B-D-galactopyranosyl (1-4) - A-D-glucopyranose

Question 28

what are homopolysaccharides?

Answer 28

polymers containing 1 type of monosaccharide

Question 29

what are heteropolysaccharides

Answer 29

polymers containing more than 1 type of monosaccharide

Question 30

how is glucose stored?

Answer 30

in polymeric forms

Question 31

unbranched or branched: amylose or amylopectin

Answer 31

amylose: unbranched amylopectin: branched

Question 32

what is amylose?

Answer 32

linear polymer of glucose residues through alpha 1-4 bonds

Question 33

what is amylopectin?

Answer 33

alpha 1-4 linked glucose residues with alpha 1-6 branch points every 24-30 residues

Question 34

how does glycogen differ from amylopectin?

Answer 34

higher frequency of branch points ( every 10 residues)

Question 35

what does greater frequency of branching allow?

Answer 35

rapid mobilization

Question 36

what is cellulose made of?

Answer 36

linear, homopolysaccharide of glucose residues

Question 37

what is the principal component of hard exoskeletons?

Answer 37

chitin

Question 38

what is the difference between cellulose & chitin?

Answer 38

hydroxyl group at C2

Question 39

what do beta 1-4 linkages of cellulose & chitin allow?

Answer 39

formation of long straight chains

Question 40

how are fibrils formed?

Answer 40

parallel chains that are linked through hydrogen bonds

Question 41

what is the function of fibrils?

Answer 41

rigid structure & strength

Question 42

what linkages of starch & glycogen form a hollow helical structure?

Answer 42

alpha 1-4

Question 43

what is the function of hollow helix?

Answer 43

compact & accessible storage structure of glycogen

Question 44

what are glycoproteins?

Answer 44

proteins with covalently attached sugars

Question 45

what functions do proteoglycans have?

Answer 45

nerve structure & lubricating functions

Question 46

what are proteoglycans?

Answer 46

protein linked to a glycosaminoglycan

Question 47

what does erythropoietin do?

Answer 47

stimulates red blood cell production

Question 48

what are higher order carbohydrate structured generated through?

Answer 48

the action of glycosyltransferases