Lecture 8a-b: molecular biology- the genetic material and DNA structure

Question 1

characteristics of the genetic material:

Answer 1

• replication
• storage of information
• expression of that information
• variation by mutation

Question 2

nucleotide consists of 3 essential components:

Answer 2

a nitrogenous base
a pentose (ribose, a 5 carbon sugar)
a phosphate group

Question 3

2 kinds of nitrogenous bases

Answer 3

purines (adenine, guanine)
pyrimidines (cytosine, thymine, uracil)

Question 4

nucleotides are also described by

Answer 4

nucleoside monophosphate
nucleoside diphosphates
nucleoside triphosphates

Question 5

Messenger RNA (mRNA)

Answer 5

a transcript of the gene carries information for the synthesis of proteins

Question 6

Transfer RNA (tRNA)

Answer 6

an RNA molecular that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and recognising the appropriate codons in the mRNA

Question 7

Ribosome RNA (rRNA)

Answer 7

the most abundant type of RNA, which together with proteins forms the structure of ribosomes

Question 8

How is the genetic information coded in the DNA molecule?

Answer 8

The information must lie on the linear sequence of nitrogenous bases; i.e. the arrangement of bases

Question 9

3 possible mechanisms

Answer 9

semiconservative mechanism,
conservative mechanism,
dispersive mechanism

Question 10

DNA replication semi-conservative replication molecular processes”

Answer 10

1. “untwisting” of the DNA molecule
2. each of 2 strands works to synthesise a complementary strand
3. DNA polymerase helps link the free nucleotides to forma new strand