Transcription

Question 1

Central Dogma

Answer 1

DNA—>RNA—->Protein

Question 2

What is the specific relationship between genes and enzymes?

Answer 2

One gene-One polypeptide

Question 3

What is responsible for coding of a polypeptide?

Answer 3

A gene

Question 4

What 3 things depend on properties of proteins?

Answer 4

1. Structure
2. Function
3. Development

Question 5

Transcription

Answer 5

synthesis of an RNA copy of a segment of DNA;
DNA in nucleus, proteins synthesized in cytoplasm—-> needs a messenger—->RNA

Question 6

Translation

Answer 6

Conversion of mRNA sequence into polypeptide

Question 7

Structure of RNA

Answer 7

Contains uracil in place of thymine
has a hydroxyl group on the 2’ carbon atom of its sugar that makes it more reactive than DNA

Question 8

What types of RNA are transcribed from DNA?

Answer 8

1. mRNA
2. rRNA
3. tRNA

Question 9

What are the steps needed to turn DNA into a protein?

Answer 9

1. DNA
2. Transcription
3. mRNA, rRNA, tRNA
4. Ribosomes
5. Translation
6. Protein

Question 10

mRNA

Answer 10

encodes amino acid sequence of polypeptides

Question 11

tRNA

Answer 11

brings amino acids to ribosomes during transcription

Question 12

rRNA

Answer 12

functional and structural components of ribosomes

Question 13

snRNA

Answer 13

small neclear RNA, role in RNA processing

Question 14

Transcription Process

Answer 14

1. Initiation: Promoter interacts with RNA polymerase to begin process
2. Elongation: DNA is transcribed into RNA transcript
3. Termination: transcription stops

Question 15

Promoter

Answer 15

tells RNA Poly where to start copying

Question 16

Coding sequence

Answer 16

Transcribed “RNA to be”

Question 17

Terminator

Answer 17

Tells RNA Poly where to stop coding

Question 18

Promoter

Answer 18

Sequences critical for specifying initiation of transcription
RNA polymerase binds to promoter
1st loosely to the -35 box while DNA is still double stranded
Binds more tightly and DNA unwinds at -10 box

Question 19

Elongation

Answer 19

Transcription Bubble
RNA polymerase untwists DNA as it moves along strand
Temporary DNA-RNA hybrid formed at a rate of 30-50 nucleotides/sec

Question 20

Termination sequence

Answer 20

Specifies where transcription will stop
Recognized by RNA polymerase or rho (protein)
RNA polymerase dissociates and it stops

Question 21

What are the 3 polymerases of RNA?

Answer 21

RNA poly I: mostly rRNA synthesis
RNA poly II: mRNA and some snRNA
RNA poly III: tRNA and some snRNA

Question 22

what is precursor mRNA?

Answer 22

product of transcription that has to be processed to produce functional mRNA

Question 23

Precursor mRNA contains?

Answer 23

1. Introns: intervening seq not translated
2. Exons: expressed seq, translated

Question 24

mRNA splicing

Answer 24

removal of introns from precursor mRNA

Question 25

What two things are added to mRNA during RNA processing?

Answer 25

Modified at both 5’-3’ ends
5’ gets an additional G - 5’ capping
3’ gets an additional poly AAAA tail