BLG1501 MAY 2018 MEM0

UNISA
BLG1501 Memorandum
May/June 2018 EXAMINATION
100 Marks
SEMESTER 1

Question 1

1.1 An atom is defined as the smallest particle of _____
A. a compound that can take part in chemical reaction.
B. an element that can take part in chemical reaction. ✔
C. a molecule that reacts with other molecules.
D. an isotope that take part in chemical reaction.
E. a compound that react with other compounds.

1.2 The three domains of life are _____
A. eukarya, fungi and bacteria.
B. eukarya, archaea and bacteria. ✔
C. eukarya, fungi and animalia.
D. eukarya, archaea and fungi.
E. eukarya, bacteria and animalia

1.3 The correct definition of isotopes is _____
A. atoms of the different elements that have the same number of neutrons,
but differ in the number of protons.
B. atoms of the same element containing the same number of protons, but
differ in the number of electrons.
C. atoms of the same element containing the same number of protons,
but differ in the number of neutrons. ✔
D. atoms of the same element containing the same number of electrons, but
differ in the number of neutrons.
E. atoms of different elements that have the same number of neutrons, but
differ in the number of electrons.

1.4 Van der Waals interaction is a bond formed by _____
A. polar positively charged and polar negatively charged atoms.
B. polar positively charged and non-polar negatively charged atoms.
C. non-polar positively charged and non-polar negatively charged
atoms.✔
D. positively charged and negatively charged atoms.
E. non-polar positively charged and negatively charged atoms.

1.5 Chitin is an example of a _____
A. polypeptide.
B. polysaccharide. ✔
C. fat.
D. nucleic acid.
E. glycerol.

, 1.6 The electron configuration 1s22s22p4, belongs to _____
A. carbon.
B. oxygen. ✔
C. nitrogen.
D. neon.
E. magnesium.

1.7 Ribosomes are responsible for _____
A. protein synthesis. ✔
B. digestive compartments.
C. photosynthesis.
D. controlling the centre of the cell.
E. the removal of waste from the cell.

1.8 The mass number refers to _____
A. the number of protons in an atom.
B. the combined number of protons and neutrons in an atom. ✔
C. the number of electrons in an atom.
D. the combined number of protons and electrons in an atom.
E. the number of neutrons and electrons in an atom.

1.9 Chloroplasts are responsible for _____
A. the shipping and receiving centre.
B. digestive compartments.
C. photosynthesis. ✔
D. controlling the centre of the cell.
E. protein synthesis.

1.10 In DNA, double helix, adenine pairs with _____, and guanine pairs with _____
A. cytosine, thymine.
B. guanine, adenine.
C. uracil, cytosine.
D. thymine, cytosine. ✔
E. cytosine, uracil.

Total: 20


Question 2

2.1 Describe the structure and functions of four polysaccharides. (8)

Answer:

Starch = Glucose polymer that is a storage polysaccharide in plants.
Helical glucose polymer with alpha 1-4 linkages

Glycogen = Glucose polymer that is a storage polysaccharide in animals.
Large glucose polymer that is more highly branched (alpha 1-4 and 4-6 linkages)