Chapter 4.4

Question 1

How are disaccharides formed?

Answer 1

• glycosidic bonds formed between two hydroxyl groups of two monosaccharides
• > results in a dissacharide
• > water is formed

Question 2

What are the three types of disaccharides? How are they formed

Answer 2

1) sucrose
- >glucose+ fructorse

2) lactose
- >galactose+glucose

3) maltose
- >glucose+ glucose

Question 3

What are polysaccharides?

Answer 3

-a monosaccharide linked together by glycosidic bonds

Question 4

Contrast homopolysaccharide from a heteropolysaccharide

Answer 4

homopolysaccharide
->a polymer made up of one type of monosaccharide

heteropolysaccharide
->a polymer made up of one type of monosaccharide

Question 5

What kind of monosaccharide is cellulose, starch and glycogen made up of

Answer 5

-they are all composed of the same monosaccharide, D-glucose

Question 6

How does branching occur in a sugar polymer

Answer 6

• monosaccharide in a polymer chain forms at least two glycosidic bonds
• > allows branch formation

Question 7

Describe the characteristics of cellulose

Answer 7

• the main structural component of plants(D-glucose)
• a homopolysaccharide
• > linked by Beta-1,4 glycosidic bonds
• > hydrogen bonds hold the actual polymer chains together for support

Question 8

Can we digest cellulose

Answer 8

• humans are not able to digest cellulose

- >because we lack those enzymes

Question 9

What are the two types of starch. Note one is branched or unbranched

Answer 9

Amylose
->linear glucose polymer linked by alpha-1,4 glycosidic bonds

Amylopectin

• > has linear glucose polymer linked by alpha-1,4 glycosidic bonds
• > also alpha-1,6 glycosidic bonds(forms branches)

Question 10

Describe alpha-amylase and beta-amylase

Answer 10

alpha

• > cleaves randomly along the polysaccharide chain
• > to create shorter chains, maltose and glucose

beta
->cleaves amylose at the nonreducing end of the polymer to yield MALTOSE

Question 11

Describe the characteristics of glycogen

Answer 11

• carbohydrate storage unit in animals
• similar to starch
• > except that it has more alpha-1,6 glycosidic bonds

Question 12

How does increased branching in glycogen affect it?

Answer 12

• branching optimizes the energy efficiency of glycogen
• > makes it more soluble in solution
• > allows more glucose to be stored in the body

Question 13

How does glycogen phosphorylase work

Answer 13

• it works on glycogen
• cleaves glucose from the nonreducing end of a glycogen branch
• > phosphorylates it to cleave the nonreducing end
• > produces glucose 1-phosphate