Module 10 - Microbial Genetics

Question 1

What is the genome

Answer 1

All DNA present in a cell or a virus

Question 2

What are the two types of genome? What has what?

Answer 2

Haploid 1N: Bacteria & Archaea
Diploid 2N: Eukaryotes

Question 3

What is a genotype?

Answer 3

A specific set of genes an organism possesses

Question 4

What is a phenotype?

Answer 4

A collection of observable characteristics

Question 5

What is transcription

Answer 5

A process that yields an RNA copy of specific genes (mRNA)

Question 6

What is translation

Answer 6

Decoding mRNA to synthesize a polypeptide

Question 7

What is replication

Answer 7

DNA makes a copy of itself

Question 8

What is the central dogma

Answer 8

The flow of genetic information, DNA->RNA->Protein

Question 9

What are the 3 differences between DNA and RNA

Answer 9

-Deoxyribose vs ribose
-Bases AGCT vs AGCU
-Single vs double stranded

Question 10

How is prokaryotic DNA organized

Answer 10

Circular double helix / supercoiled DNA

Question 11

How is eukaryotic DNA organized

Answer 11

Chromatin where it is associated with histones (nucleosome)

Question 12

DNA synthesis is _____ conservative and why?

Answer 12

semi, because half of each daughter is made of the parent and the other half of each is a new strand

Question 13

What type of prokaryote may have more than one origin of replication?

Answer 13

Archaea

Question 14

Replication in prokaryotes is (direction)

Answer 14

Bidirectional

Question 15

What is DNA polymerase

Answer 15

Catalyzes the synthesis of the complementary strand of DNA

Question 16

What direction is DNA synthesis

Answer 16

5’ to 3’

Question 17

What are the three requirements of polymerase to synthesize DNA

Answer 17

Template, primer, dNTPs (nucleotides)

Question 18

What is DNA polymerase III

Answer 18

Protein complex, catalyze synthesis, proof read, bind both strands of DNA at the same time. Proofreads

Question 19

What does DnaB do

Answer 19

Breaks the H bonds between strands essentially splitting the helix

Question 20

What does DnaA do

Answer 20

Binds to the origin of replication and directs DnaB to break the bonds

Question 21

What is Helicase (replisome)

Answer 21

Unwind DNA strands

Question 22

What are SSBs (replisome)

Answer 22

Hold the two strands apart

Question 23

What is topoisomerase

Answer 23

Relieve the tension caused by rapid unwinding by knicking the strands

Question 24

What is primase

Answer 24

Creates a primer at the origin of replication

Question 25

How is the leading strand synthesized

Answer 25

Polymerase III synthesizes it continuously from 5'-3'

Question 26

What is the leading strand

Answer 26

The top strand leading from 5'-3'

Question 27

How is the lagging strand synthesized

Answer 27

Synthesized using small okazaki fragments. Multiple primers needed

Question 28

What is the lagging strand

Answer 28

Bottom strand, 3'-5'

Question 29

What is Ligase

Answer 29

reattaches the Okazaki fragments

Question 30

What are the 3 steps in transcription

Answer 30

Initiation: unwinding DNA Elongation: RNA synthesis, complementary nucleotides added Termination: terminator sequence reached

Question 31

What is used transcription in bacteria

Answer 31

polycistronic mRNA

Question 32

What is a gene

Answer 32

A nucleic acid sequence that codes for a polypeptide

Question 33

What is a codon

Answer 33

A code for a single amino acid

Question 34

Where do we start reading codons

Answer 34

Initiation - AUG

Question 35

What is the coding region

Answer 35

The region that begins with AUG and ends with a stop codon

Question 36

What is a holoenzyme

Answer 36

Core enzyme + sigma factor

Question 38

Explain 7 steps of DNA replication, direction, and location

Answer 38

1. helicase breaks helix 2. ssb stabilizes and prevents reannealing 3. primase makes the primer to guide polymerase iii 4. polymerase iii places nucleotides 5. polymerase i replaces primers 6. ligaments connects okazaki fragments 7. topoisomerase relieves tension, 5’-3’ nucleus

Question 39

What is initiation in transcription, location, direction

Answer 39

RNA polymerase bonds to promoter indicated by the TATA or pribnow box. nucleus or cytoplasm 5’-3’

Question 40

What is elongation in transcription

Answer 40

RNA polymerase unwinds DNA and slides along the template strand adding nucleotides

Question 41

What is termination in transcription

Answer 41

Sequence in DNA causes a loop OR rho causes RNA polymerase to dissociate

Question 42

How does transcription differ in eukaryotes and prokaryotes

Answer 42

Eukaryotes vs Prokaryotes nucleus / cytoplasm TATA / pribnow Cap & poly A tail / none Intron splicing / none monocistronic / polycistronic

Question 43

What are the 3 things required by DNA polymerase for synthesis

Answer 43

1. nucleotides 2. primer 3. template