Carbohydrates – monosaccharides, disaccharides, polysaccharides

Question 1

what are carbon containing molecules known as?

Answer 1

organic molecules

Question 2

what is a monomer?

Answer 2

smaller units that join together to make larger molecules

Question 3

give three examples of monomers

Answer 3

1. monosaccharides
2. amino acids
3. nucleotides

Question 4

what is a polymer?

Answer 4

a molecule formed when monomers join together forming long chains.

Question 5

give three examples of polymers.

Answer 5

1. polysaccharides
2. proteins
3. DNA/RNA

Question 6

what is the basic monomer unit in carbohydrates?

Answer 6

Sugar (saccharide)

Question 7

what is a single monomer called?

Answer 7

a monosaccharide

Question 8

what is a pair of combined monosaccharides called?

Answer 8

a disaccharide

Question 9

give three examples of monosaccharides

Answer 9

1. glucose
2. galactose
3. fructose

Question 10

give three examples of disaccharides

Answer 10

1. maltose (glucose + glucose)
2. sucrose (glucose + fructose)
3. lactose (glucose + galactose)

Question 11

what is the test for reducing sugars?

Answer 11

Benedicts test

Question 12

describe the Benedict’s test

Answer 12

1. add 2cm3 of food sample to a test tube (if it is not already in liquid form grind it up in water)
2. add an equal volume of Benedict’s reagent
3. heat the mixture in a water bath at 100ºc for 5 minutes

Question 13

what would a positive result for the Benedict’s test for reducing sugars show?

Answer 13

the solution will turn from blue to a orange-brown

Question 14

what colours may show in a semi-quantitive use go the Benedict’s test? (none to high concentration)

Answer 14

Blue – green – yellow – orange – red