M2-C3-L05 --> Microbial Genetics I

Front 1

In DNA polymerase, what type of nucleotides can be used?

Back 1

Deoxynucleotide 5' Triphosphates

Front 2

In order for DNA polymerase to add nucleotides, what must be laid down first?

Back 2

Primer is required

Front 3

Describe the exonuclease activity for Prokaryote polymerases.

Back 3

DNA Pol I:
5' to 3' and 3' to 5'

DNA Pol II: --> don't need to know
3' to 5'

DNA Pol III:
3' to 5'

Front 4

Which prokaryote DNA polymerase has a very high elongation rate.

Back 4

The WORKHORSE

DNA Pol III -- 30,000 bases/min

(DNA Pol I is 600)

Front 5

Describe the elongation of the lagging strand.

Back 5

RNA primer get placed

DNA Pol III
attaches & elongates,
but fall off at next primer
(b/c no 5' to 3' exonuclease activity)

DNA Pol I
jumps on and chews up RNA primer,
AND fills in gap before falling off.

DNA ligase joins the fragments.

Front 6

In Prokaryotes, what is the RNA Polymerase CORE consist of?

Back 6

Just the RNA polymerase

Front 7

In Prokaryotes, what is the RNA Polymerase HOLOENZYME consist of?

Back 7

RNA polymerase and Sigma factor

Front 8

What does sigma factor do in Prokaryotes?

Back 8

Aids RNA polymerase in recognizing promoters.

Front 9

Promoters in Prokaryote transciption, is rich in what?

Back 9

T and A (e.g. - TATA box)

Front 10

In Prokaryote transcription,

- what elongates mRNA
- what unwinds DNA

Back 10

Both are done by RNA Polymerase

Front 11

Describe the Rho Independent termination of Prokaryotes.

Back 11

Hairpin with string of U's on mRNA

Bond created with U's are thermodynamically unstable.

Front 12

Transcription for Eukaryote vs. Prokaryote:

- RNA Polymerases
- mRNA x3
- Coupling

Back 12

Eukaryote have 3 RNA Polymerases
Prokaryotes have 1 RNA Polymerase

Eukaryote mRNA is:
- long lived
- modified at 5' and 3' ends
- Monocistronic

Bacterial transcription and translation is coupled in Bacteria

Front 13

What enzyme ensure fidelity in translation?

Back 13

Amino acid - tRNA synthetase

Front 14

Initiation of Bacterial Translation requires what? x5

Back 14

tRNA
Initiation Factors (IFs) x3
mRNA
Energy
Ribosome Subunits (30S & 50S)

Hint 14

TIMER

Front 15

Bacterial Ribosome

- A site does what?
- P site does what?
- E site does what?

Back 15

Arrival of the Amino acid

Production of the Peptide bond btw amino acids

Ejaculation of the protein

Front 16

Gene regulation occurs at what level for:

- Prokaryotes
- Eukaryotes

Back 16

Level of transcription
(tho may occur @ level of translation)

Level of translation

Front 17

In bacteria, gene regulation at the transcription level means what? x2

Back 17

mRNA very unstable

Rapid response to environmental changes

Front 18

In bacteria, gene transcription is coupled with what?

Back 18

coupled with translation

Front 19

In bacteria, genes are grouped into what?

Back 19

Grouped into operons

Front 20

For microbial genetics, define Operon

Back 20

UNIT of DNA
that is
COORDINATELY regulated

and

transcribed into a single
POLYCISTRONIC
mRNA

Front 21

For microbial genetics, define the term Inducible

Back 21

Substance must be added to induce gene expression

Front 22

For microbial genetics, define the term Repressible

Back 22

Substance must be added to repress gene expression

Front 23

For microbial genetics, define the term Negative Control

Back 23

When regulatory protein is bound to DNA, Operon is OFF

Front 24

For microbial genetics, define the term Positive Control

Back 24

When regulatory protein is bound to DNA, Operon is ON

Front 25

Gene function forms the basis of what function?

Back 25

Cell function

Front 26

If cloning of DNA, what is useful to study?

Back 26

microbes

Front 27

E. coli DNA

- Length
- Replication rate

Back 27

1.3 meters (4 million bases)

100,000 bases/minute

Front 28

Which E. coli polymerases can synthesize from:

- intact DNA
- Primed ssDNA
- Primed ssDNA + SBP

Back 28

None

DNA Pol I

DNA Pol I & DNA Pol II

Front 29

Describe the addition of nucleotides in terms of which ends react with which molecules.

Back 29

3' OH of first nucleotide reacts with

5' Triphosphate of second nucleotide

Front 30

What are the phases of RNA SYNTHESIS?

Back 30

Initiation

Elongation

Termination

Front 31

Bacterial ribosome contains how many:

- proteins
- RNA's

Back 31

50+

3

Front 32

Number of:

- Total triplet codons
- Start codons (list)
- Stop codons (list)

Back 32

61

1 (AUG)

3 (UGA, UAA, UAG)

Front 33

Define Degenerate

Back 33

More than one codon for many amino acids

Front 34

Describe tRNA wobble

Back 34

3rd position is variable for many codons coding for same amino acid

Front 35

Describe what happened in the "Trojan Horse Experiment" involving tRNA.

Back 35

Cys-tRNA chemically changed to Ala-tRNA.

During translation,
the Ala-tRNA binded to Cys codons

Front 36

Ensuring Fidelity in translation

Amino acid + ATP --> ???

Back 36

(Amino acid)-(AMP)

Front 37

Ensuring Fidelity in translation

(Amino acid)-(AMP) + tRNA --> ???

Back 37

(Amino acid)-(tRNA)