Lab 3.1 (Central Dogma)

Question 1

Replication in prokaryotes is very similar to that of eukaryotes. State the three key differences.

Answer 1

Enzymes used, the number of ORI, and the termination process.

Question 2

Essential to this process is the separation of the double helix DNA into single strands that would serve as templates.

Answer 2

Initiation

Question 3

The enzyme needed is the helix unwinding protein (HUP) or otherwise known as?

Answer 3

helicase

Question 4

What is used to unwind the DNA by breaking the hydrogen bonds at the single origin of replication initiation (ORI) site?

Answer 4

ATP

Question 5

A group of helix destabilizing proteins that prevent the strands from reannealing.

Answer 5

single strand binding proteins

Question 6

Relaxes supercoils created during unwinding.

Answer 6

DNA gyrase

Question 7

Synthesized by _________ to serve as primers for the elongation of the complementary strands.

Answer 7

RNA primase

Question 8

Provide free 3’OH needed by DNA polymerase
III.

Answer 8

RNA Primase

Question 9

Adds nucleotides to both leading and lagging strands.

Answer 9

DNA polymerase III

Question 10

“proof-reads” the DNA nucleotides that were added, removes incorrect nucleotides, and adds the correct nucleotides.

Answer 10

DNA Polymerase II

Question 11

Removes the RNA primers and replaces them
with DNA nucleotides.

Answer 11

DNA Polymerase I

Question 12

in termination, DNA nucleotides of both strands are joined together by?

Answer 12

DNA ligase.

Question 13

A protein called ________ binds to the_________ of the DNA, which is usually located opposite the ORI.

Answer 13

1. terminus utilization substance (TUS)
2. termination recognizing sequence (ter)

Question 14

Is the transcription process where the transfer of information is from a double- stranded DNA molecule to a single-stranded RNA molecule.

Answer 14

RNA synthesis

Question 15

How is the holoenzyme formed?

Answer 15

A polypeptide called sigma factor associates with RNA Polymerase to form the holoenzyme

Question 16

Recognize the transcription initiation site or promoter.

Answer 16

Holoenzyme

Question 17

Is characterized by specific base sequences on the DNA molecule.

Answer 17

Promoter

Question 18

In Transcription: elongation, This substance continues to add RNA nucleotides to the template strand until it reaches the termination site.

Answer 18

RNA Polymerase

Question 19

Transcription: Termination occurs in two ways, Which are?

Answer 19

rho-independent and rho-dependent.

Question 20

Also known as intrinsic termination.

Answer 20

Rho-independent

Question 21

Towards the terminal end of the mRNA, there are complementary sequences called?

Answer 21

inverted repeats

Question 22

This serves as the termination site of transcription.

Answer 22

Hairpin Loop Structure

Question 23

The final product of transcription is?

Answer 23

messenger RNA (mRNA)

Question 24

Binds with proteins to form small and large subunits of the ribosome.

Answer 24

ribosomal RNA (rRNA)

Question 25

Is tasked to deliver amino acids.

Answer 25

Transfer RNA (tRNA)

Question 26

Recall that the small and large ribosomal subunits have 3 sites, which are?

Answer 26

the E-site, the P-site, and the A-site.

Question 27

It acts as the ribosomal binding site, allowing the subunit to locate the start codon immediately.

Answer 27

Shine-Dalgarno sequence

Question 28

Initiator tRNA (with anticodon complementary to the start codon), picks up the initial amino acid Which is?

Answer 28

formyl-methionine.

Question 29

What helps the amino acid binds to the initiator tRNA?

Answer 29

amino acyl synthetase

Question 30

With the aid of amino acyl synthetase, the amino acid binds to the initiator tRNA forming the?

Answer 30

tRNA-fmet complex.

Question 31

Binds to the small ribosomal subunit to prevent the large ribosomal subunit from binding to it prematurely.

Answer 31

IF3

Question 32

Binds to the A-site of the small ribosomal subunit to ensure that the initiator tRNA-fmet complex will be at the P-site (later).

Answer 32

IF1

Question 33

Recruits the initiator tRNA-fmet complex and guides it to the P-site of the ribosome.

Answer 33

IF2

Question 34

Start codon;

Answer 34

AUG

Question 35

The initial amino acid methionine will then be transferred from the first tRNA to the second tRNA in a process called?

Answer 35

transpeptidation

Question 36

The ribosome then undergoes ________ to free the A-site, ready to accept the next tRNA.

Answer 36

translocation

Question 37

Occurs when the ribosome reaches the stop codon (either UAA, UAG, or UGA).

Answer 37

Termination

Question 38

Since there is no anticodon for the stop codon, this factor binds to the stop codon,

Answer 38

cytoplasmic release factor

Question 39

A cytoplasmic release factor binds to the stop codon, signaling this enzyme to bind the synthesized amino acid chain (polypeptide) to a molecule of
water.

Answer 39

peptidyl transferase