Definitions

Question 1

Stereoisomers

Answer 1

same order and types of bonds
different arrangements of OH groups
different chemical properties
have at least 1 chiral carbon

Question 2

chiral carbon

Answer 2

attached to 4 diff atoms or groups of atoms

2^n = stereoisomers; n= chiral carbon

Question 3

enantiomers

Answer 3

stereoisomers which are mirror images and non superimposable

Question 4

diastereomers

Answer 4

stereoisomers which are not mirror images at 1 or more of their asymmetric carbons

Question 5

Epimers

Answer 5

stereoisomers that differ in position of the hydroyxyl group at only 1 of their asymmetric carbons

an epimer is also a diastereomer

Question 6

D & L sugar form

Answer 6

D- OH on Right on the chiral C furthest from carbonyl group
L- OH on Left
D & L sugars are mirror images & non superimposable
D is most common

Question 7

enantiomers

Answer 7

2 molecules which are mirror images of each other and not superimposable

Question 8

epimerases

Answer 8

enzymes which interconvert a sugar to its epimer

Question 9

Anomeric Carbon

Answer 9

in ring structure- former carbonyl carbon becomes asymmetric
OH group is attached to carbon
alpha - down
beta - up

Question 10

anomers

Answer 10

isomeric forms of monsacharides that differ only in their configuration at hemiacetal or hemiketal carbon atom

alpha + beta

Question 11

mutorotation

Answer 11

in soln, OH of anemic carbon can spontaneously change from alpha to beta position

Question 12

Mutarotase

Answer 12

enzyme that changes anemic carbon from alpha to beta

Question 13

O-glycosidic bond

Answer 13

covalent link
OH group of 1 sugar reacts with the anomeric carbon of the other
Condensation Reaction

Question 14

reducing end

Answer 14

has the free anomeric carbon

Question 15

non-reducing end

Answer 15

loss of anomeric carbon

has been added to polysaccharide

Question 16

N-glycosidic bond

Answer 16

anomeric carbon of sugar reacts with amine group of another compound
e.g. nucleotides

Question 17

disaccharides

Answer 17

contain 2 monosaccharides joined by O-glycosidic bond

alpha or beta configuration

Question 18

Lactose

Answer 18

glucose + galactose
beta 1,4
go good luck

Question 19

Fehling’s reaction

Answer 19

generates red precipitate
to test amt of reducing sugar
reducing end/free anomeric carbon can be oxidized by Fehling reagent => color

Question 20

Polysaccharides

Answer 20

10-1000s of monsaccharides linked by glycosidic bonds to produce linear chains or branched structures
most carb in nature= polysaccharide
e.g. Starch - most common in diet

Question 21

Amylose

Answer 21

plant starch

glucose connected by alpha 1,4 linkages

Question 22

Amylopectin

Answer 22

plant starch
branched structure
glucose connected by alpha 1,4 linkages and branched every 24-30 residues by alpha 1,6 linkages

Question 23

Glycogen

Answer 23

polymer of alpha 1,4 linked glucose units

with alpha 1,6 linked branches every 8-12 residues

Question 24

Advantages of storing glucose in polymeric form

Answer 24

minimizes osmotic effects of intracellular glucose

highly branched structure permits rapid glucose release form glycogen stores

Question 25

Non digestable carbohydrates

Answer 25

dietary fibers - resistant to digestion by human digestive enzymes insoluble fibers- cellulose and hemicellulose soluble fibers- pectins, gums, mucilages

Question 26

glycosaminoglycan

Answer 26

component of extracellular matrix repeating disaccharides unit heteropolysaccharides

Question 27

fructose

Answer 27

ketose hexose fructofuranose

Question 28

glucose

Answer 28

aldose hexose glucopyranose

Question 29

sucrose

Answer 29

glucose + fructose alpha 1, 2, go father son