Lecture 9: Connecting Monosaccharides

Question 1

Glycosidic Bond

Answer 1

• Bond formed between the anomeric carbon of a monosaccharide and an alcohol

Question 2

Talk about the open form of glucose

Answer 2

• Open form of glucose can react with oxidizing agents like Cu2+ because of the aldehyde group.

Question 3

Reduction and oxidation in terms of hydrogen

Answer 3

Oxidation is the loss of hydrogen. Reduction is the gain of hydrogen.

Question 4

Monosaccharide and reducing sugars:

Answer 4

All monosaccharides are reducing sugars because all monosaccharides have an aldehyde group (if they are aldoses) or can tautomerize (c=o to c=c) in basic solution to form an aldehyde group (if they are ketoses).

Question 5

Why is sucrose not a reducing sugar?

Answer 5

Both anomeric carbon are locked in a glycosidic bond and cant open to a ketone/aldehyde

Question 6

Glycogen (2)

Answer 6

• a homopolymer: made solely of glucose units
• Mostly α 1,4-glycosidic bonds but the branches are formed by α 1,6-glycosidic bonds (every 10 glucose units)

Question 7

Homopolymer

Answer 7

Homopolymer is a polymer that is made up of only one type of monomer unit

Question 8

Starch (3)

What it is+ plants+ kind

Answer 8

• a homopolymer of glucose units
• Nutritional reservoir in plants
• two kinds: Amylose and amylopectin

Question 9

Amylose

Answer 9

linear α-1,4-glycosidic bonds

Question 10

Amylopectin

Answer 10

one α-1,6-glycosidic bond per 30 α-1,4-glycosidic bonds