Topic 1 - Exam Questions

Question 1

Compare and contrast the structure of a disaccharide with glycogen (4 Marks)

Answer 1

~ Both contain glycosidic bonds.

~ Both contain glucose.

~ Glycogen contains 1-4 and 1-6 glycosidic bonds, whereas disaccharides only contain 1-4 glycosidic bonds.

~ Glycogen only contains glucose, whereas disaccharides contain other molecules such as fructose and galactose.

Question 2

Define the term mass transport system (1 mark)

Answer 2

Bulk movement of gases or liquids in one direction, via a system of vessels.

Question 3

Explain the role of hydrogen bonding and its importance in transporting water (2 Marks)

Answer 3

~ Allows water molecules to stick together.

~ Hydrogen bonds form between other molecules of water.

Question 4

Water is described as dipole in nature.

With reference to covalent bonding, explain the dipole nature of water molecules (3 Marks)

Answer 4

~ Covalent bonding occurs between an oxygen and two hydrogen atoms.

~ Therefore oxygen is slightly negative and hydrogen is slightly positive.

~ Water is therefore a polar molecule.

Question 5

The ester bond plays an important role in the biochemistry of lipids.

Describe the role of the ester bond within lipids and the mode of ester bonds formation and breakage (3 Marks)

Answer 5

~ They link fatty acids and glycerol.

~ Formed during a condensation reaction.

~ Broken during a hydrolysis reaction.

Question 6

(4 Marks)

Answer 6

~ 1 = Fat around major organs.

~ 2 = Maintain body temperature.

~ 3 = Cholesterol in cell membranes.

~ 4 = Acts as a shock absorber.

Question 7

Compare and contrast the structures of saturated and unsaturated fatty acid (4 Marks)

Answer 7

~ Both have hydrocarbon tails.

~ Both have -COOH group at the end.

~ Saturated fatty acid have no c-c double bonds.

~ Unsaturated fatty acids have c-c double bonds.

Question 8

Explain why increased blood pressure causes an increase in the risk of CVD (3 Marks)

Answer 8

~ Lead to atherosclerosis.

~ Leading to an atheroma formation.

~ Leading to thrombosis.

Question 9

A diuretic increases urine production.

Explain how a diuretic may reduce blood pressure and relieve the symptoms (2 Marks)

Answer 9

~ Reduces blood volume.

~ Reducing blood pressure.

Question 10

Compare and contrast the structures of alpha and beta glucose (4 Marks)

Answer 10

~ Both hexose sugars.

~ Both have a ring structure.

~ Alpha glucose has the H above and the OH group below C1.

~ Beta glucose has the H below and the OH group above C1.

Question 11

State TWO features of a glycosidic bond that forms between two monosaccharides in a condensation reaction (2 Marks)

Answer 11

~ Covalent bond.

~ Forms between C1 and C4 (1-4 GB).

~ Forms between C1 and C6 (1-6 GB).