Everything Science Grade 12

CHAPTER 2. ORGANICMACROMOLECULES 2.6

Exercise 2 - 4

1. For each of the following, say whether the statement is true or false. If the state-
   ment is false, give a reason for your answer.

(a) Deoxyribonucleic acid (DNA) is an exampleof a polymer and a nucleotide

is an example of a monomer.

(b) Thymine and uracilare examples of nucleotides.

(c) A person’s DNA will determine what proteins their body will produce, and

therefore what characteristics they will have.

(d) An amino acid is a protein monomer.

(e) A polypeptide that consists of five amino acids, will also contain five nu-

cleotides.

2. For each of the following sequences of nitrogenous bases, write downthe amino
   acid/s that will be part of the polypeptide chain.

(a) UUU

(b) UCUUUU

(c) GGUUAUGUUGGU

3. A polypeptide chainconsists of three aminoacids. The sequence ofnitrogenous
   bases in the nucleotidesof the DNA is GCUGGUGCU. Give the structural for-
   mula of the polypeptide.

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Chapter 2 — Summary

See the summary presentation ( Presentation: VPmvi at http://www.everythingscience.co.za)

• A polymer is a macromolecule that is made up of many repeating structural units
  called monomers which are joined by covalent bonds.


• Polymers that containcarbon atoms in the main chain are called organic poly-
  mers.


• Organic polymers canbe divided into natural organic polymers (e.g. natural
  rubber) or synthetic organic polymers (e.g. polystyrene).