Carbohydrates

Question 1

what sugar molecule is the most abundant

Answer 1

glucose

Question 2

what is the formula for carbohydrates

Answer 2

Cn(H2O)n

Question 3

carbohydrates are called ____ _______ aldehydes/ketones

Answer 3

poly hydroxy

Question 4

what are monosaccharides? can they be broken down? and some examples

Answer 4

simplest sugar units that cant be broken down
ex. glucose, galactose, fructose

Question 5

sucrose = __________ + __________
maltose = __________ + __________
lactose = __________ + __________

Answer 5

glucose + fructose
glucose + glucose
glucose + galactose

Question 6

examples of polysaccharides

Answer 6

starch (flour/potatoes) and cellulose (cotton/cell wall)

Question 7

D = last OH on fischer proj _____
L = last OH on fishcher proj _____

Answer 7

D = right
L = left

Question 8

what are epimers

Answer 8

sugars that differ config on only 1 C
(OH on right vs. OH on left on one of the C)

Question 9

on a fischer projection which C are aldehydes/ketones on

Answer 9

aldehydes = C1
ketones = C2

Question 10

amino sugar vs. deoxy sugar

Answer 10

amino sugar = OH replaced by NH2
deoxy sugar = OH replaced by H

Question 11

anomeric carbon? for aldoses? for ketoses

Answer 11

carbons that are attached to 2 O atoms
aldoses = C1
ketoses = C2

Question 12

D sugars (haworth)

L sugars (haworth)

Answer 12

a = OH down
b = OH up
CH2OH = up

a = OH up
b = OH down
CH2OH = down

Question 13

what are anomers

Answer 13

the same sugar, different anomeric config

Question 14

what is mutarotation and how does it occur

Answer 14

when sugars change their anomeric config in the presence of solvent/water. Occurs when sugars have hemiacetals (reducing ends)

ex. a —- b or b —- a

Question 15

can glycosides undergo mutarotation

Answer 15

no they cant bc glycosides are acetals

Question 16

naming sugar alcohols
D-glucose + NaBH4 =

Answer 16

D-glucitol

Question 17

what do sugar alcohols have on the end of their structures

Answer 17

have 2 CH2OH, one on each end.

Question 18

what reagent are sugar alcohols being reduced with

Answer 18

NaBH4

Question 19

are meso compounds optically active and chiral

Answer 19

No

Question 20

what do oxidizing agents do

Answer 20

convert aldehyde into COOH

Question 21

oxidizing agent ex

Answer 21

Tollens Reagent

Question 22

what does Tollens Reagent do

Answer 22

oxidizes aldehydes into COOH

Question 23

sugars that react with oxidizing agents are called _______. The reagent is _______ and the sugar is ________.

Answer 23

reducing sugars

reagent = reduced
sugar = oxidized

Question 24

Tollens test?

Answer 24

• tests for aldehydes and hemiacetals
• unreactive towards acetals (glycosides) and polysaccharides

Question 25

Can ketoses like fructose react with Tollens Reagent

Answer 25

yes they can, only if they have a ene-diol interconversion. (ketone to aldehyde)

Question 26

Unknown structure question if sugar is unreactive towards Tollens Reagent, what does that mean? What type of linkage would this sugar have?

Answer 26

it means its a acetal so a glycoside (a/b) 1-1 linkage

Question 27

the acetal end is called the _______ end

Answer 27

non reducing

Question 28

the hemiacetal end is called _________ reducing end

Answer 28

reducing end

Question 29

what is the anomeric effect

Answer 29

axial substiuents for EN groups (O,OH,F) in a-anomer, equatorial for EP groups (N) ex. OH is down for a-anomer = axial

Question 30

what is the inverse anomeric effect

Answer 30

equatorial substituents for EN groups (O, OH, F) in b-anomer, axial for EP groups (N) ex. OH is up for b-anomer = equatorial

Question 31

Solvent Effect? polar solvent (h2o, dmso) = ________ forces non polar solvent (CDCL3, THF) = _________ forces

Answer 31

intermolecular forces bc they can bind with solvent for stability. Solvent - H - Sugar intramolecular forces bc they cant h bond with solvent, they h bond with sugars for stability Sugar - H - Sugar

Question 32

how to name glycosides/glycosidic linkages

Answer 32

(D/L) - sugarsyl - (a/b 1- ) - (D/L) - sugar(pyranose/furanose)

Question 33

what rxn breaks apart polysaccharides

Answer 33

hydrolysis

Question 34

what rxn makes di/polysaccharides

Answer 34

condensation/dehydration rxn

Question 35

what does sugar methylation do

Answer 35

protects the anomeric carbon from other rxns

Question 36

what does acetalation do to sugar alcohols

Answer 36

converts OH to OAc pyranose on C1 and C5 furanose on C1 and C4

Question 37

glycosidases and example

Answer 37

enzymes that cleave specific sugars in glycosides b-galactosidase = cleaves b-galactose

Question 38

what does dextran do

Answer 38

seperates polysaccharides into monosaccharides

Question 39

what linkage is starch made of

Answer 39

poly a(1-4) D-glucose links

Question 40

what are the 2 forms of starch

Answer 40

amylose (plants) and amylopectin (human foods)

Question 41

function of starch

Answer 41

energy storage unit and feul

Question 42

what linkage is amylose made of

Answer 42

poly a(1-4) D-glucose links

Question 43

function of amylose

Answer 43

energy storage unit in plants

Question 44

function of glycogen

Answer 44

energy storage unit in humans/animals

Question 45

what linkage is glycogen made of

Answer 45

poly a(1-4) + a(1-6) D-glucose links, more (1-6 links)

Question 46

What type of structure does amylose form

Answer 46

tightly coiled helical structure

Question 47

homopolysaccharide examples

Answer 47

starch, cellulose, chitan, chitosan

Question 48

heteropolysaccharide examples

Answer 48

peptidoglycans, GAGS, proteoglycans, glycolipids/lipopolysaccharides, glycoproteins

Question 49

function of cellulose

Answer 49

provides structure and rigidity to plant cell walls

Question 50

what linkage is cellulose made of

Answer 50

poly b(1-4) D-glucose links

Question 51

what is the structure of cellulose

Answer 51

formation of long fibers that stack onto each other through h bonding

Question 52

function of chitan

Answer 52

exoskelatal component of arthopods (insects, crabs, lobsters)

Question 53

what is the second most abundant polysaccharide

Answer 53

chitan

Question 54

what is the first most abundant polysaccharide

Answer 54

cellulose

Question 55

what linkage is chitan made of

Answer 55

poly b(1-4) N-acetylglucosamine NAG links

Question 56

what linkage is chitosan made of

Answer 56

deacytylated poly b(1-4) D-glucosamine links

Question 57

how is chitosan made

Answer 57

chitan + NAOH = chitosan

Question 58

function of peptidoglycans

Answer 58

structural component of bacterial cell wall

Question 59

what linkage are peptidoglycans made of

Answer 59

poly b(1-4) NAG and NAM

Question 60

what are GAGs made of

Answer 60

repeating disaccharide units of acetylated amino sugar + uronic acid

Question 61

where are GAGs found

Answer 61

ECM, specifically connective tissue

Question 62

what are proteoglycans made of

Answer 62

GAGs + proteins

Question 63

where are proteoglycans found

Answer 63

ECM, specifically connective tissue

Question 64

example of proteoglycan

Answer 64

hyaluronic acid

Question 65

function of proteoglycans

Answer 65

provides hydration and skin elasticity

Question 66

function of glycoprotiens

Answer 66

aids in cell-cell recognition and cell signalling

Question 67

structure of glycoproteins

Answer 67

oligosaccharide sugar + proteins

Question 68

Glycosylation O-linked = N-linked =

Answer 68

Serine/Threonine Asparginine