Carbohydrates: Monosaccharides

Question 1

What is the unusual feature of carbon atoms?

Answer 1

carbon atoms readily form bonds with other carbon atoms

Question 2

why are carbon containing molecules known as organic molecules?

Answer 2

Because all life that we have identified has been carbon-based

Question 3

What is the difference between a monomer and a polymer?

Answer 3

Monomer - a single molecule (e.g. Polythene and Polyester)

Polymer - a chain of bonded monomers (e.g. Starch)

Question 4

Name the elements that make up most of the polymers in nature.

Answer 4

Carbon, Oxygen, Hydrogen and Nitrogen.

Question 5

Name the three chemical elements contained in carbohydrates.

Answer 5

Carbon, Hydrogen and Oxygen Carbo.

Question 6

Describe the two main functions of carbohydrates in living organisms.

Answer 6

• Structural roles in cell walls

- Carbohydrates are a respiratory substrate from which cells release the energy required to carry out their functions.

Question 7

Arrange the different carbohydrates in size order, starting with the smallest.

Answer 7

Smallest - Monosaccharides
next - Disaccharides
Biggest - Polysaccharides

Question 8

Glucose and Fructose have the same chemical formula (CH,2O). So how can they exist as two different monosaccharides?

Answer 8

Because the carbon, hydrogen and oxygen atoms can be arranged differently.

Question 9

Draw the simplified version of a-glucose

Answer 9

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Question 10

Explain why benedict’s reagent turns brick red when heated with a reducing sugar.

Answer 10

Reducing sugars donate electrons from their reducing centres to blue copper (II) sulphate, forming copper (I) oxide - a brick red percipitate.