TOPIC 1 EXAM QUESTIONS

Question 1

The general structure of a fatty acid is RCOOH.
Name the group represented by COOH.

Answer 1

CARBOXYL GROUP

Question 2

Describe how a triglyceride molecule is formed.

Answer 2

1. One glycerol and three fatty acids;
2. Condensation (reactions) and removal of three molecules of water;
3. Ester bond(s) (formed);

Question 3

Describe how an ester bond is formed in a phospholipid molecule.

Answer 3

) 1. Condensation (reaction)
OR
Loss of water;

2. Between of glycerol and fatty acid;

Question 4

WATER ESSAY

Answer 4

Monomers and polymers – carbohydrates – lipids –
proteins
3.1.7 Water
3.2.3 Transport across membranes – osmosis – water
potentials
3.3.2 Gas exchange – plants
3.3.2 Gas exchange – fish
3.3.2 Gas exchange – insects
3.3.4.1 Mass transport in animals - blood – circulation
3.3.4.1 Mass transport in animals – tissue fluid and
formation

3.3.4.2 Mass transport in plants – transpiration stream
3.3.4.2 Mass transport in plants – translocation
3.5.1 Photosynthesis
3.5.4 Nutrient cycles – leaching and eutrophication
3.6.1 Growth responses in plants
3.6.4 Homeostasis
3.6.4.3 Control of blood and water potential

Question 5

Describe the structure and function of the nucleus

Answer 5

1. Nuclear envelope and pores
   OR
   Double membrane and pores;
2. Chromosomes/chromatin
   OR
   DNA with histones;
3. Nucleolus/nucleoli;
   Function
4. (Holds/stores) genetic information/material
   for polypeptides (production)
   OR
   (Is) code for polypeptides;
5. DNA replication (occurs);
6. Production of mRNA/tRNA
   OR
   Transcription (occurs);
7. Production of rRNA/ribosomes;

Question 6

Compare and contrast the structure of starch and the structure of cellulose

Answer 6

1. Both polysaccharides
   OR
   Both are glucose polymers
   OR
   Both are made of glucose monomers;
2. Both contain glycosidic bonds (between
   monomers);
3. Both contain carbon, hydrogen and oxygen/C, H
   and O;
4. Starch has α-glucose and cellulose has βglucose;
5. Starch (molecule) is helical/coiled and cellulose
   (molecule) is straight;
6. Starch (molecule) is branched and cellulose is
   not/unbranched;
   7.Cellulose has (micro/macro) fibrils and starch
   does not;

Question 7

Describe the complete digestion of starch by a mammal.

Answer 7

1. Hydrolysis;
2. (Of) glycosidic bonds;
3. (Starch) to maltose by amylase;
4. (Maltose) to glucose by disaccharidase/maltase;
5. Membrane-bound (disaccharidase/maltase);