Carbohydrates

Question 1

Biochemical test for non-reducing sugar (3)

Answer 1

-heat with acid and neutralise
-heat with Benedict’s solution
-red precipitate

Question 2

How can you measure the quantity of reducing sugar without a colorimeter? (2)

Answer 2

-filter and dry precipitate
-find mass

Question 3

What is the difference in the structures of starch and cellulose? (2)

Answer 3

-starch has alpha glucose and cellulose has beta glucose
-positions of H and OH is inverted

Question 4

Why are hydrogen bonds important in cellulose molecules? (2)

Answer 4

-form cross links b/t chains to form microfibrils providing strength
-more H bonds add more strength

Question 5

Why is a spiral shape of starch important to its function? (1)

Answer 5

-compact

Question 6

Why does salivary amylase not affect digestion of starch?

Answer 6

-little digestion of starch by salivary amylase
-amylase secreted by pancreas
-most digestion in small intestine