L13 - Carbohydrate Metabolism 1.1

Question 1

Define:

a) Cellulolysis
b) Glycogenolysis
c) Amylolysis

Answer 1

a) Cellulolysis - Degradation of Cellulose (hydrolysis)
b) Glycogenolysis - Degradation of Glycogen (hydrolysis and phosphorolysis)
c) Amylolysis - Degradation of Starch (hydrolysis)

Question 2

What does Phosphorolysis use?

Answer 2

Phosphoric acid - H3PO4

Question 3

Describe the production of a and B maltose from amylose

Answer 3

1) a-amylase (an endoglucosidase) hydrolyses amylose - results in formation of the disaccharide a-maltose and glucose
2) b-amylase (an exoglucosidase) results in formation of b-maltose by hydrolysis from non-reducing end

Question 4

What processes does Glycogenolysis involve

Answer 4

both hydrolysis and phosphorolysis

Question 5

What 2 reactions are involved in the breakdown of Glycogen?

Answer 5

1) Glycogen phosphorylase
- removes single units from non-reducing end via phosphorolysis
- producing glucose-1-phosphates

2) Glycogen is branched, so another 2 enzymes are used to get rid of branches once they are only 4C long:
a) first Transferase transfers 3Cs to the non-reducing end of an adjoining chain (hydrolysis and condensation)
b) then a-1,6-glucosidase is used to cut the single remaining C off the branch

Question 6

What is reduced in each:

a) aerobic respiration
b) anaerobic respiration

Answer 6

a) O2 is reduced to water as a result of oxidising the carbohydrates
b) No oxygen involved so some other compound is reduced

Question 7

In anaerobic respiration, if the compound that is broken down is organic, what is the process called?

Answer 7

fermentation

Question 8

What 2 enzymes are used to break down cellulose?

Answer 8

Endoglucanase and Exoglucanase