Lecture 17 - The Central Dogma

Question 1

What is the central dogma?

Answer 1

DNA->RNA->Protein

Question 2

Can you start with protein and go to RNA or DNA?

Answer 2

No

Question 3

After DNA replication, one strand is the ____ strand and one strand is the _____ strand

Answer 3

Maternal strand and daughter strand

Question 4

What is at each end of replicated DNA?

Answer 4

Telomeres

Question 5

What enzyme builds DNA in DNA replication?

Answer 5

DNA polymerase

Question 6

Is there a leading/lagging strand in the process of DNA replication?

Answer 6

Yes

Question 7

Is there a leading/lagging strand in the process of transcription?

Answer 7

No

Question 8

What enzyme builds mRNA in transcription?

Answer 8

RNA polymerase

Question 9

Where in the cell does transcription take place?

Answer 9

In the nucleus

Question 10

Each tRNA can bind how many amino acids?

Answer 10

ONLY 1

Question 11

What does tRNA contain that reads the codon in mRNA?

Answer 11

Anticodon

Question 12

Explain the ribosomal differences in eukaryotes and prokaryotes (bacteria)

Answer 12

Prokaryotes: 30s+50s=70s
Eukaryotes: 40s+60s=80s

S=sedimentation unit

Question 13

The bigger the sedimentation unit, the _____ it goes to the bottom of the centrifuge

Answer 13

Faster

Question 14

How many possible choices are there for codons? How many amino acids are there?
What conclusion can be drawn from the answer to these 2 questions

Answer 14

64 possible choices for codons but there’s only 20 amino acids
=redundancies

Question 15

What are the 3 steps of translation?

Answer 15

Initiation, elongation, termination

Question 16

Which recognizes the Shine Dalargno sequence?
-prokaryotes or eukaryotes

Answer 16

Prokaryotes

Question 17

What is the Shine Dalargno sequence?

Answer 17

Short sequence of mRNA where rRNA can recognize to start translation

Question 18

mRNA meets the _____ subunit of rRNA, then the _____ subunit

Answer 18

Small then large

Question 19

What high energy molecule is utilized in the initiation step of translation?

Answer 19

GTP

Question 20

Name the initiation factor

Answer 20

IF-3

Question 21

What is the termination step?

Answer 21

Recognition of the stop codon and hydrolysis to release the newly synthesized protein

Question 22

What is happening in the elongation step of translation?

Answer 22

A longer and longer peptide chain is being created

Question 23

Is transcription and translation simultaneous in both prokaryotes and eukaryotes? Explain

Answer 23

NO - only simultaneous in bacteria
This cannot happen in eukaryotes because of the presence of the nucleus. Transcription MUST take place in the nucleus and then exported. Bacteria do not have a nucleus

Question 24

What is the first amino acid added in bacteria(prokaryotes)?

Answer 24

FMET

Question 25

What is the first amino acid added in eukaryotes?

Answer 25

MET

Question 26

What does “co translational modification” mean?

Answer 26

The change of one or more amino acids during translation

Question 27

Give 5 examples of co translational modification

Answer 27

-folding -deformylation (fmet to met) -removal of a few N terminal amino acids -changing conformation of proline -N glycolysation

Question 28

What does post translational modification mean?

Answer 28

The change of one or more amino acids AFTER translation

Question 29

Give 5 examples of post translational modification

Answer 29

-O glycolsylation -disulfide formation -splicing -lipidation -Ubiquitination

Question 30

Phosphorylation, acetylation, etc are examples of co or post translational modification?

Answer 30

Post

Question 31

What would happen if a drug destroyed proteosomes?

Answer 31

Protein with ubiquitine would build up which would cause energy waste and hurt the cell - we would die

Question 32

A proteosome consists of _____ particles on the ends and a_____ particle in the middle

Answer 32

Regulatory particles on the ends with a core particle in the middle

Question 33

When an amino acid is added to its corresponding tRNA, ATP is converted to ____ as a ____reaction

Answer 33

AMP as a coupled reaction