Chapter 6- Microbial Genetics

Question 1

What is DNA replication

Answer 1

Flow from one generation to the next during cell division

Question 2

What is DNA recombination

Answer 2

Flow from one cell to another in the same generation

Question 3

What is gene expression

Answer 3

Transcribed and translated DNA to produce proteins needed for cellular function

Question 4

DNA replication is …

Answer 4

Semiconservative (one parent strand and one daughter strand)

Question 5

DNA polymerase III can only synthesize in …

Answer 5

5’ to 3’ direction

Question 6

What strand is synthesized continuously

Answer 6

The leading strand

Question 7

What strand is synthesized in small pieces (Okazaki fragments) that are eventually hooked together

Answer 7

The lagging strand

Question 8

How is the fidelity of DNA replication accomplished

Answer 8

1. Base paring

2. Proof

Question 9

DNA polymerase III and I can detect incorrect nucleotides that are not complementary and remove them by chewing back the new strand from 3’ end

Answer 9

3’ to 5’ exonuclease activity

Question 10

What is transcription

Answer 10

The synthesis of a complementary strand of RNA

Question 11

What is the enzyme for transcription

Answer 11

RNA polymerase (protein)

Question 12

What is the enzyme for translation

Answer 12

RNA (in ribosome)

Question 13

Core enzyme of RNA polymerase

Answer 13

αββ’ω

Question 14

Holoenzyme of RNA polymerase

Answer 14

αββ’ω PLUS σ

Question 15

What subunit of RNA polymerase is the one that recognizes the promoter

Answer 15

Sigma subunit

Question 16

When there is more then one codon per amino acid

Answer 16

Degeneracy

Question 17

What amino acids are the exception of degeneracy

Answer 17

Methionine and tryptophan

Question 18

Start codon

Answer 18

AUG

Question 19

Stop (nonsense) codons

Answer 19

UAA, UAG, UGA

Question 20

How does 30S subunit binds to mRNA

Answer 20

By recognizing Shine-Dalgarno (SD) sequence

Question 21

How is transcription and translation in prokaryotes

Answer 21

Coupled

Question 22

What is an Operon

Answer 22

Prokaryotic transcriptional units whose expression is controlled by a single regulator sequence

Question 23

When RNA polymerase transcribes a long mRNA encoding more then one polypeptide what is it called

Answer 23

Polycistronic RNA

Question 24

What is negative transcription

Answer 24

When a regulatory protein inhibits transcription when it binds DNA.

Question 25

What is positive regulation

Answer 25

When a regulatory protein stimulates transcription when it binds DNA

Question 26

Repression

Answer 26

A type of negative transcriptional regulation in which transcription of an operon is inhibited (repressed) when a particular chemical (effector= corepressor) is present

Question 27

Induction

Answer 27

A type of negative transcriptional regulation in which the transcription of an operon is stimulated (induced) when a particular chemical (effector=inducer) is present