Carbohydrates Worksheet by Curtis Bustos

                                                                                                   

Chem 3810-001                                                       Name:

Breakout Problem: carbohydrates

1. Fill in the blanks:

Monosaccharide	Monosaccharide	Disaccharide
Fructose		Sucrose
Galactose	Glucose
	Glucose	Maltose

2. Identify D or L for glucose:

3. Circle the anomeric carbons. Identify whether they are alpha or beta.

     

4. Draw the products alpha-D-fructose and beta-D-fructose (remember, right in the Fischer projection translates to down in the Haworth projection if you arrange your ring so the carbons go clockwise):

 

5. As mentioned in lecture, sucrose was not a reducing sugar due to fructose (aka fructofuranose). Is alpha-D-Fructose (monomer) a reducing or non-reducing sugar? Explain.

6. Draw the structure of the disaccharide O-beta-D-mannose-(1à4)-beta-D-mannose-6-sulfate.  Is this a reducing or non-reducing sugar?

 carbohydrates                                                                   KEY

1. Fill in the blanks:

Monosaccharide	Monosaccharide	Disaccharide
Fructose (ketose)	Glucose	Sucrose
Galactose (aldose)	Glucose	Lactose
Glucose	Glucose	Maltose

 2. Identify D or L for glucose:

                                 D-Glucose                                            L-Glucose

3. Circle the anomeric carbons. Identify whether they are alpha or beta.

     

4. Draw the products alpha-D-fructose and beta-D-fructose (remember, right in the Fischer projection translates to down in the Haworth projection if you arrange your ring so the carbons go clockwise):

5. As mentioned in lecture, sucrose was not a reducing sugar due to fructose (aka fructofuranose). Is alpha-D-Fructose (monomer) a reducing or non-reducing sugar? Explain.

Fructose by itself is a reducing sugar because it has a hemiketal anomeric-carbon.

6. Draw the structure of the disaccharide O-beta-D-mannose-(1à4)-beta-D-mannose-6-sulfate.  Is this a reducing or non-reducing sugar?

 

Answer: O-beta-D-mannose-(1à4)-beta-D-mannose-6-sulfate. This is a reducing sugar.