KH2

Question 1

What is the central dogma and information flow

Answer 1

DNA synthesis (replication), RNA synthesis (transcription), protein synthesis (translation)

Question 2

Transcription has what kind of interaction of template with incoming monomer

Answer 2

Direct

Question 3

What is the sequence of RNA transcribed from

Answer 3

A region of DNA that corresponds to the sequence of the non-template strand

Question 4

What is the relationship between the non-template strand and the newly synthesized RNA strand and the template DNA strand

Answer 4

They are both complementary to and antiparallel to the template DNA strand

Question 5

How is the template DNA strand exposed

Answer 5

By local unwinding of duplex DNA by helical associated with RNA polymerase

Question 6

What happens after the original DNA duplex was unwound in the transcription bubble

Answer 6

It reforms behind RNA polymerase as it moves unidirectional along the DNA

Question 7

How is the newly synthesized RNA strand kicked out

Answer 7

The reforming duplex behind the polymerase kicks it out

Question 8

Where does the displaced single-stranded RNA exit through

Answer 8

A channel in the polymerase, 5’ end first

Question 9

What facilitates the initial binding of RNA polymerase to DNA

Answer 9

DNA sequences called promoters

Question 10

How does synthesis of RNA stop

Answer 10

Certain DNA sequences destabilize the attachment of RNA polymerase to the DNA as it moves. The RNS falls off the DNA and releases the RNA

Question 11

What are the similarities between DNA replication and RNA transcription

Answer 11

1. Template = DNA
2. DNA duplex locally unwound by a helical at initial sites to expose template
3. New strand synthesized 5’ to 3’ antiparallel to template, chain growth at 3’ end
4. Monomers = nucleoside triphosphates
5. Direct interaction between template DNA and incoming monomer
6. Attack of 3’ OH- on alpha phosphate of incoming dNTP, beta and gamma phosphate dropped

Question 12

Differences in DNA replication and transcription monomers

Answer 12

T: rNTPs
D: dNTPs

Question 13

Differences in start sites and stop sites between transcription and DNA replication

Answer 13

T: start and stop sites on template
D: Start sites (origins) but no stop sites

Question 14

Differences in strand separation between transcription and DNA replication

Answer 14

T: newly synthesized strand (RNA) separates from template strand
D: Newly synthesized strand (DNA) never separates from template strand

Question 15

Differences in template strands between transcription and DNA replication

Answer 15

T: only one of the original DNA strands is a template strand (start with one molecule of double stranded DNA and we end with that DNA plus RNA)

D: Both of the original DNA strands independently serve as template strands (start with one molecule of double stranded DNA and end with 2)

Question 16

What is translation

Answer 16

Protein synthesis

Question 17

How many nucleotides are in codons

Answer 17

3

Question 18

Which processes use direct interaction of template with next monomer molecule to be incorporated

Answer 18

Replication and transcription

Question 19

Which process uses indirect interaction between template and next monomer to be incorporated

Answer 19

Translation (tRNA acts as an adaptor between template and growing chain)

Question 20

What is the template for translation and what is the energized monomer

Answer 20

mRNA and aminoacyl tRNA (adaptor)

Question 21

What is the function of aminoacyl tRNAs

Answer 21

Adaptors for transforming a nucleotide signal into an amino acid signal

Question 22

What is the relationship of the 3-nucleotide anticodon to the codon on the mRNA

Answer 22

It is a sequence that is complementary to the codon

Question 23

What is the structure of a ribosome

Answer 23

A ribonucleo-protein particle (RNA + protein) consisting of large and small subunits

Question 24

What is the peptidyl transferase reaction catalyzed by

Answer 24

The large subunit RNA molecule

Question 25

What is heredity

Answer 25

How DNA replicates itself

Question 26

What is the language analogy of DNA, RNA and protein synthesis

Answer 26

DNA and RNA synthesis are in the same language (nucleotides) but different fonts (deoxyribose or ribose) and protein synthesis is in a different language (amino acids)

Question 27

Is there any information in the backbone of DNA

Answer 27

No

Question 28

Where does RNA polymerase start transcription

Answer 28

At the promoter

Question 29

What are rNTPs

Answer 29

Nucleotides that have been polymerized

Question 30

How does RNA eventually fall of DNA strand

Answer 30

As RNA polymerase is moving along it holds on to DNA
Some DNA sequences have weak connection to RNA polymerase (stop sequence)
Polymerase falls off, RNA falls off

Question 31

What is direct interaction

Answer 31

There isn’t only contact with the monomer but also the part of the monomer going to be incorporated

Question 32

What is the make-up of a ribosome

Answer 32

50% RNA 50% protein

Question 33

What does peptidyl transferase do

Answer 33

Transfers growing peptide from one tRNA to the next

Question 34

Where is the protein actually made in translation

Answer 34

Amino acid signal end

Question 35

What is a key reaction in the ribosome in translation

Answer 35

Ribosome joins N from next tRNA to previous tRNA C