Module 1.2 DNA

Question 1

Features of Genetic Material

3

Answer 1

Stable storage of information
Faithful transmission of information
Information retrieval and expression

Question 2

Nucleotide components

3

Answer 2

• a deoxyribose (5-carbon sugar)
• a nitrogenous base (nucleobase)
• a phosphate group

Question 3

DNA nitrogenous bases

Pyrimidines

Answer 3

One ring
Cytosine (C)
Thymine (T)

Question 4

DNA nitrogenous bases

Purines

Answer 4

Two rings
Guanine (G)
Adenine (A)

Question 5

Polynucleotide Formation

sugar-phosphate backbone

phosphodiester bond

Answer 5

the -OH on the 3’ carbon of the previous nucleotide’s ribose bonds with the phosphate group on the 5’ carbon of the next nucleotide’s ribose
5’ phosphate head, 3’ -OH tail

Question 6

Watson-Crick Model

DNA traits

structural and functional

Answer 6

double-stranded helix
anti-parallel orientation: strands go in opposite directions
right-handed: railing on right side going upstairs
base-pairing specificity
semiconservative replication

Question 7

Discovery of DNA

Frederich Miescher

Answer 7

Swiss physiological chemist that isolated ‘nucleins’ from cell nuclei in 1869

Question 8

Discovery of DNA

Albrecht Kossel

Answer 8

German biochemist that renamed ‘nucleins’ as DNA in 1881

Question 9

DNA as Genetic Material

Frederick Griffith’s transformation experiment (1928)

Answer 9

evidence for hereditary component

non-virulent rough (r) strain of S. pneumoniae ‘transformed’ by
virulent heat-killed smooth (s) strain to make the r strain virulent

Question 10

DNA as Genetic Material

Avery, McLeod, and McCarty’s Experiment (1944)

Answer 10

Heat- killed s-strain virulent cell components were exposed to protease, RNase, or DNase, then mixed with r-strain S. pneumoniae. DNase-treated components only one not to have r-strain transformed to s-strain

Demonstrated that transforming principle was DNA not protein

Question 11

DNA structure

nucleotide component attachment points

Answer 11

nucleobase attached to ribose at carbon 1
phosphate group attached to ribose at carbon 5

Question 12

DNA structure

nucleoside

Answer 12

nucleobase and ribose (no phosphate group)
eg answer triphosphate

Question 13

DNA structure

Nucleotides:
dGMP
dAMP
dTMP
dCMP

full chemical names

Answer 13

deoxyguanisine monophosphate
deoxyadenosine monophosphate
deoxythymidine monophosphate
deoxycytidine monophosphate

Question 14

DNA structure

DNA base pairings

Answer 14

Adenine and Thymine (2 hydrogen bonds)
Cytosine and Guanine (3 hydrogen bonds)