Chapter 3

Question 1

Nucleotides

Answer 1

A constituent of nucleic acids, consisting of a 5-carbon sugar, a nitrogen containing base & one or more phosphate groups

Question 2

Nucleoside

Answer 2

the combination of sugar and bases

Question 3

Central Dogma

Answer 3

the usual flow of genetic info in a cell from DNA -> RNA -> protein

Question 4

Transcription

Answer 4

the genetic info in a molecule of DNA is used as a template to generate a molecule of RNA

Question 5

Translation

Answer 5

A molecule of RNA is used as a code for the sequence of amino acids in a protein

Question 6

Three Differences between DNA & RNA

Answer 6

1. RNA sugar is ribose (which carries a hydroxyl group on the 2’ carbon) & DNA is deoxyribose 2. the bast U (uracil) in RNA replaces T (thymine) in DNA 3. the 5’ of DNA is typically a monophosphate, in RNA the 5’ end is typically a triphosphate

Question 7

RNA Transcript

Answer 7

the RNA sequence synthesized from a DNA template

Question 8

RNA Polymerase

Answer 8

the enzyme that carries out the polymerization, adds successive nucleotides to the 3’ end of the growing transcript

Question 9

3 Transcription Stages

Answer 9

1. Initiation 2. Elongation 3. Termination

Question 10

Initiation

Answer 10

RNA polymerase and other proteins are attracted to double-stranded DNA: the DNA strands separate and transcription of template begins

Question 11

Elongation

Answer 11

successive nucleotides are added to the 3’ end of the growing RNA transcript as the RNA polymerase process along the template strand

Question 12

Termination

Answer 12

the RNA polymerase encounters a sequence in the template strand that causes transcription to stop and the RNA transcription to be released

Question 13

Promoter Sequence

Answer 13

5’-TATAAA-3’

Question 14

Sigma Factor

Answer 14

a protein that associates with RNA polymerase that facilitates its binding to specific promoters