Metabolism: Carbohydrates

Question 1

Draw the structure of glucose and fructose

Answer 1

Question 2

Draw the structure of D-glyceraldehyde

Answer 2

Question 3

Draw the structure of D-Erythrose

Answer 3

Question 4

Draw the structures of the following 5 carbon aldose sugars:

Ribose

Arabinose

Xylose

(How will you remember these?)

Answer 4

Ribose = literally Glyceraldehyde w/ 2 extra carbons

Arabinose: ribose w/ OH and H flipped at C2

Xylose: Ribose w/ OH and H flipped at C3

Question 5

Draw the structures of the following 5 carbon aldose sugars:

Ribose

Arabinose

Xylose

(How will you remember these?)

Answer 5

Ribose = literally Glyceraldehyde w/ 2 extra carbons

Arabinose: ribose w/ OH and H flipped at C2

Xylose: Ribose w/ OH and H flipped at C3

Question 6

Draw the structures of the following 5 carbon aldose sugars:

Ribose

Arabinose

Xylose

(How will you remember these?)

Answer 6

Ribose = literally Glyceraldehyde w/ 2 extra carbons

Arabinose: ribose w/ OH and H flipped at C2

Xylose: Ribose w/ OH and H flipped at C3

Question 7

Draw the structures of the following 6 carbon aldose sugars

Glucose

Mannose

Galactose

Answer 7

Question 8

Draw the structures of the following 6 carbon aldose sugars

Glucose

Mannose

Galactose

Answer 8

Question 9

Draw the structures of the following 6 carbon aldose sugars

Glucose

Mannose

Galactose

Answer 9

Question 10

Which 3 carbon ketose sugar is this?

Answer 10

Question 11

Below is the structure of ___, which can become ___ when phosphorylated at C6.

Answer 11

Fructose

F6P

Question 12

What intermediates can aldoses and ketoses form that allows them to form polymers?

Answer 12

Aldose: Hemicetal

Ketose: Hemiketal

Question 13

Define a reducing sugar

Answer 13

One that can be oxidized back to its chair conformation

Question 14

How do you form a glycosidic bond? How do you break a glycosidic bond?

Answer 14

Condensation reaction to form a glycosidic bond

Hydrolysis reaction to break the glycosidic bond