Week # 7 Carbohydrates

Lectures # 18, 19

Concepts:

Recognize various types of carbohydrates including monosaccharides, disaccharides, polysaccharides, hexose, pentose, aldose, ketose.

Recognize the structures of the above with alpha and beta

Recognnize hemiacetal and acetal functional groups in the various saccharides

Ques. 1. List 3 disaccharides and list the monosaccharides present in each.

Ques. 2. List 3 polysaccharides and state where they can be found in nature.

Ques. 3. Which hexose is also a ketose?

Ques. 4. For the two structures below:


a. Identify glucose and galactose.

b. Identify the alpha and beta hemiacetal OH's.

Review: Combination Reactions

14. Hemiactal Synthesis / Alcohol + aldehyde or ketone
à hemiacetal / Make a ring:
4-hydroxypentanol
15. Acetal Synthesis
(ether synthesis) / Alcohol + hemiactal
à acetal + water / Above hemiacetal with ethanol


Ques. 5; Identify the alpha and beta glucose and the alpha and beta galactose in the structures above.


Ques. 6: a. Which structure is alpha ………and beta fructose?

b. Which structure A or C is a aldose ………and a pentose?

c. Which structure B or D is a ketose ………and a hexose?

Ques. 7. Write the complete synthesis reaction starting with the monosaccarides for the formation of:

maltose

sucrose


Ques. 8: a. Which structure is maltose? And which is lactose?

b. Which arrow letter points to an alpha acetal or glycosidic bond?

c. Which arrow letter points to an beta acetal or glycosidic bond?

d. Which arrow letter points to an alpha anomeric carbon? … an alpha anomeric carbon?


Ques. 9: a. Which structure is sucrose? … fructose?

b. Which structure is glucose?

c. Which arrow letter points to a alpha acetal or glycosidic bond?

d. Which arrow letter points to a beta anomeric carbon?

Ques. 10. List the di- or polysaccharides with alpha - acetal linkages. Same for beta - acetal linkages.

Ques. 11. What are the differences and similarities for starch, glycogen, and

cellulose.

Ques. 12.


a. The common names for structures A, B, C, are abd give the reason for your choices:

A= B= C=

b. Which structure(s) is a hexose?

c. List the arrow numbers which point to alpha OH anomeric carbons.

d. List the arrow numbers which point to beta OH anomeric carbons.

e. List the arrow numbers which point to beta acetal linkages.

f. Put a circle around ALL hemiacetal groups in ALL structures.

g. Which structure is a ketose? A pentose?