2Monosaccharides

Question 0

Base all sugars on which molecule?

Answer 0

D-Glyceraldehyde

     CHO
        l
H-   C  - OH*
        l
       CH2O

Question 1

Most sugars are _____handed sugar

Answer 1

Right-handed

Question 2

Aldose sugars have ____

Answer 2

Aldehyde group

Question 3

Remember the six types of aldose sugars:

Answer 3

(3) D – glyceraldehyde,
(4) D – erythrose,
(5) D – ribose,
(6) D – glucose, D – mannose, D – galactose

Question 4

D-Erythrose structure (4)

Answer 4

H     O
   \  //
H-C-OH
     l
H-C-OH*
     l
   CH2OH

Question 5

D-Threose structure (4)

Answer 5

H   O
     \  //
      C
       l
OH-C-H
       l
H-  C- OH*
       l
     CH2OH

Question 6

D-Ribose structure(5)

Answer 6

H     O
  \   //
    C
     l
H-C-OH*
     l
H-C-OH*
     l
H-C-OH*
     l
CH2OH

Question 7

D-Arabinose

Answer 7

Just know similar to ribose

   H     O
     \   //
      C
       l
HO-C-H
       l
 H- C-OH
      l
H- C-OH
      l
CH2OH

Question 8

D-Xylose structure (5)

Answer 8

Just remember similar to ribose

  H    O
   \    //
     C
      l
 H-C-OH
      l
HO-C-H
       l
H- C-OH
      l
CH2OH

Question 9

The reference compound for naming D and L isomers of sugars is:

Answer 9

Glyceraldehyde

Question 10

D-Glucose structure

R-L-R-R

Answer 10

H   O
    \   //
     C
      l
H- C-OH
      l
OH-C-H
      l
H- C-OH
      l
H- C-OH
     l
CH2OH

Question 11

D- Mannose structure
(Only c#2 changed from glucose)

LLRR

Answer 11

H    O
    \  //
      C
       l
HO-C-H
       l
HO-C-H
       l
H-  C-OH
       l
H-  C-OH
       l
 CH2OH

Question 12

D-Galactose (6Carbons)

C#4 is different

RLLR

Answer 12

H    O
    \   //
      C
       l
  H-C-OH
       l
HO-C-H
       l
HO-C-H
       l
H- C-OH
      l
  CH2OH

Question 13

What is epimeric pair?

Answer 13

D- glucose and D-mannose

Question 14

Two major classes- the Aldose and ketose sugars

Answer 14

Glyceraldehyde (an aldotriose)

  H     O
   \    //
     C
      l
H-  C-OH
      l
H- C-OH
     l
      H

Dihydroxyacetone (a ketotriose)

     H
      l
H- C-OH
      l
     C=O
      l
H- C-OH
     l
    H

Question 15

Ketose Sugars-2 structures to know

Answer 15

Dihydroxyacetone (3 carbons)
CH2OH
 l
C=O
l
CH2OH

D-fructose (6carbon) 
    CH2OH
       l
      C=O
       l
HO-C-H
       l
H-  C-OH
      l
H-  C-OH
      l
CH2OH

Similar to glucose except ketone at C#2

Question 16

Which of the following is an epimeric pair?

2 isomers differ in configuration at one stereo center

Answer 16

D-glucose and D-mannose

Question 17

Which of the following monosaccharides is not an Aldose?

Answer 17

Fructose

Question 18

When the linear form of glucose cyclizes, the product is an:

Answer 18

Hemiacetal

Question 19

Draw glyceraldehyde. How many stereoisomers can there be?

Answer 19

2

Question 20

Draw glycerol. How many stereoisomers are there?

Answer 20

1

Question 21

D-glucose is epimeric ex on carbon #2. What did it become?

Answer 21

D-mannose

Question 22

Is D-2 deoxyglucose the same thing as D-2-deoxygalactose?

Answer 22

No

Question 23

What biochemical feature is common in cellulose and is not found in glycogen?

Answer 23

Beta 1-4 bonds

Glycogen has alpha 1-4 bond

Question 24

Which of the following monosaccharides is not an Aldose ?

Answer 24

Fructose

Question 25

Hemiacetal is made up of:

Answer 25

Aldehyde + Alcohol

Question 26

Hemiacetal can react with additional alcohols and form...

Answer 26

Acetal + water This reaction makes it less spontaneous and more stable. Split out water and more difficult.

Question 27

Ketone + alcohol=

Answer 27

Hemiketal

Question 28

Hemiketal can react with additional alcohol to form

Answer 28

Ketal

Question 29

2 glucose molecules react: Carbon #4 alcohol + hemiacetal carbon #1

Answer 29

Disaccharide form with acetal linkage Glc(alpha 1➡️4) Glc Reducing sugar because of the right side of the right sugar it still has a free carbon number one which is a hemiacetal which can still open up to form an aldehyde and therefore still has the ability to become a reducing sugar.

Question 30

Galactose+ glucose

Answer 30

Lactose Reducing sugar Gal(Beta1➡️4) Glc Galactose is almost identical to glucose but carbon number four is flipped compared to glucose so the OH group will be on top and the H group will be on bottom Reducing sugar because the hemiacetal on the right still has the anime roc carbon free, carbon#1 is free. Hemiactrals can open up freely to aldehydes.

Question 31

Glucose + Fructose

Answer 31

Table sugar- sucrose * not a reducing sugar* both a mimetic carbons tied up in bonding to each other Glc(alpha1↔️2Beta) Fru Has an acetal and ketal bond at same time. Glucose c#1 is alpha conformation with OH group coming down from it but connected to anime roc carbon of fructose, which is a ketose) so form a ketone derivative on #2 of fructose.

Question 32

2 animeric carbons of glucose attached to each other

Answer 32

Trehalose *Not a reducing sugar* Glc(alpha1↔️1 alpha) Glc

Question 33

Which two sugars is not a reducing sugar?

Answer 33

Sucrose and trehalose