Chapter 8

Question 1

Why do cells have nucleic acids and proteins?

Answer 1

Central Dogma: DNA to RNA to Proteins

Question 2

DNA replication basics:

Answer 2

Semiconservative replication, bidirectional, DNA polymerase, template, nucleotides, and primers.

Question 3

What is DNA replication timed to?

Answer 3

Cell growth and division.

Question 4

DNA gyrase:

Answer 4

Relieves positive supercoils.

Question 5

Protecting the DNA works how?

Answer 5

1. Microbial cells mark their DNA to identify it as their own.
   ex. methylating adenine or cytosine
2. Restriction endonucleases in the immune system (Recognition site and triggers the complete degradation of the DNA by nucleases that attack exposed ends.

Question 6

How do restriction endonucleases work?

Answer 6

It has a recognition site, that triggers complete degradation of DNA by nucleases that attack exposed ends.

Question 7

Nuclease:

Answer 7

Enzyme degrading nucleic acids.

Question 8

What are the unique features of prokaryotic gene expression?

Answer 8

Transcription and translation is coupled.

Question 9

Why are transcription and translation coupled?

Answer 9

1. No nucleus means translation can begin as soon as the RNA molecule is being made.
2. Allows for an extra level of regulation, called attenuation.

Question 10

What are the parts of initiation in transcription?

Answer 10

Promoter, sigma factor, RNA Polymerase, elongation, termination, (rho independent and rho dependent).

Question 11

Where are many genes found together?

Answer 11

In operons.

Question 12

What are the stable RNA types? What do they do?

Answer 12

tRNA and rRNA.
Information carriers, catalysts, and regulators.

Question 13

What does no nucleus mean in prokaryotic gene expression?

Answer 13

No nucleus means that translation can begin as soon as the RNA molecule is being made. This allows for an extra level of regulation called attenuation.

Question 14

Synthesis of RNA (transcription) initiation requires:

Answer 14

Promoter, sigma factor, and RNA polymerase

Question 15

Synthesis of RNA (transcription) termination requires:

Answer 15

Rho independent and Rho dependent

Question 16

Proteins-translation

How does processing work?

Answer 16

Covalent modification: may cleave termini, add chemical groups, signal peptides removed

*disulfide bonds

Question 17

Proteins- translation: what are the basics?

Answer 17

mRNA, tRNA, ribosomes, proteins, and amino acids

1. Initiation
2. Elongation
3. Termination

Question 18

How does protein-translation initiation work? (2 parts)

Answer 18

1. Shine-Dalgarno sequence
2. Bacteria: N-Formylmethionine- AUG

Question 19

How is 70S ribosome made?

Answer 19

Only in prokaryotes.

30S + 50S

Question 20

How is 80S ribosome made?

Answer 20

Only in eukaryotes.

40S + 60S

Question 21

Most genes are found in operons- what are operons?

Answer 21

Allows for coordinated expression of genes that function in the same biochemical pathway.

Question 22

What are the types of protein processing?

Answer 22

Covalent modification: May cleave termini, add chemical groups, and signal peptides removed. Disulfide bonds.
Protein folding: chaperones
Degradation

Question 23

How is the DNA protected?

Answer 23

1. Many microbial cells mark their DNA to identify it as their own. Methylating adenine or cytosine.
2. Restriction Endonucleases- Immune System. Recognition sites; triggers the complete degradation of the DNA by nucleases that attack exposed ends.

Question 24

Antibiotic targets of steps?

Answer 24

Quinones Novobiocin, Rifampin, Tetracycline Streptomycin, Macrolides Chloramphenicol