Carbohydrates

Question 1

What are the physiological roles of carbohydrates?

Answer 1

-Energy production in cells
-Enery storage in cells
-Structural roles in cells
-Cellular roles in cells
-Cellular identity and cell-cell interaction or signaling
-Information transfer (DNA and RNA)

Question 2

What are the two major classes of carbohydrates?

Answer 2

-Aldoses (which have an aldehyde group)
-Ketoses (which have a ketone group)

Question 3

How do you designate a sugar as D or L?

Answer 3

-The chiral carbon most distant from the carbonyl atom (ketone or aldehyde)
-The designation of D or L is relative to the reference molecule (OH)

Question 4

How can you determine the number of stereoisomers in monosaccharides?

Answer 4

-Molecules with n chiral centers will have 2^n stereoisomers
-4 chiral centers will have 16 isomers
-3 chiral centers will have 8 isomers

Question 5

What are epimers?

Answer 5

Question 6

How are hemiacetal and hemiketal cyclic structures formed?

Answer 6

Question 7

What are anomers?

Answer 7

Question 8

What are the configurations of anomeric carbons?

Answer 8

Question 9

What are pyran and furan ring structure?

Answer 9

Question 10

Describe the cyclization of glucose to glucopyranose

Answer 10

Question 11

What is mutarotation?

Answer 11

Question 12

Draw the structure of D-Ribose

Answer 12

Question 13

Draw the structure of D-Deoxyribose

Answer 13

Question 14

Draw the structure of D-Glucose

Answer 14

Question 15

Draw the structure of D-Mannose

Answer 15

Question 16

Draw the structure of D-Galactose

Answer 16

Question 17

Draw the structure of D-Fructose

Answer 17

Question 18

What are the conformations of pyranoses?

Answer 18

Question 19

Explain the cyclization of D-Fructose to Fructofuranose

Answer 19

Question 20

Describe fructose in pyran and furan ring forms in solution

Answer 20

Question 21

Describe the relationship between Haworth and Chair conformation respresentations

Answer 21

Question 22

Why is glucose the most stable pyranose?

Answer 22

Question 23

Explain galastose in Haworth and Chair representations

Answer 23

Question 24

Explain Mannose in haworth and Chair representations

Answer 24

Question 25

Draw the structure of B-D-Acetylglucosamine (NAG or GlcNAc)

Answer 25

Question 26

What are reducing agents?

Answer 26

Question 27

What is the biological formation of disaccharides?

Answer 27

Question 28

What is the nomenclature of disaccharides?

Answer 28

Question 29

What is the naming guide for disaccharides?

Answer 29

Question 30

Explain the formation of Maltose disaccharide

Answer 30

Question 31

How do you draw glycosidic bonds with haworth diagrams?

Answer 31

Question 32

Describe the disaccharide Lactose

Answer 32

Question 33

What are polysaccharides?

Answer 33

Question 34

Describe energy storage in starch and glycogen

Answer 34

Question 35

Explain energy storage in Amylose and Amylopectin (starch)

Answer 35

Question 36

Explain energy storage in glycogen

Answer 36

Question 36

What are alpha-linkages in polysaccharides?

Answer 36

Question 36

What is the structure of chitin and cellulose?

Answer 36

Cellulose hase glucose at C2 Chitin has NAG at C2

Question 37

Explain the B(1-4) in chitin and cellulose

Answer 37

Question 38

What are glycolipids?

Answer 38

-Sugars can also be covalently linked to lipid molecules to form glycolipids that are found on the cell membrane -A central function of glycolipids is in the blood group antigens -Different patterns of sugars presented on the surface of cells by the glycolipids help the body to discriminate self from non-self -Differences in the blood group antigens are critical for blood transfusions

Question 39

What are glycoproteins?

Answer 39

-Extracellular proteins with covalently attached sugars -The protein constituent is the largest component by weight -serve a variety of biological roles

Question 40

What are proteoglycans?

Answer 40

-Protein component is linked to a particular type of carbohydrate called glycosaminoglycan -The carbohydrate constituent is the largest component by weight -Often serve structural and lubricating functions in the extracellular matrix (ground substance) -Extracellular space in tissues contains a gel-like material -Ground substance holds cells together, provides a porous pathway for diffusion of nutrients/waste products and serves a cushioning function -