Exam 2: Translation

Question 1

Transcription

Answer 1

Basically, the exact same as non-template or coding strand, but Ts are Us

Question 2

Eukaryotic translation

Answer 2

Initiation factors keep ribosomal subunits separated and allow for the 5’ cap to bind to the small ribosomal subunit. Starts at 5’ AUG 3’

Question 3

Prokaryote translation

Answer 3

mRNA molecules have no 5’ cap - initiation complex is formed at one or more Shine-Dalgarno sequences

Question 4

Elongation

Answer 4

A peptide bond is formed between the Met AA and the AA that is on the tRNA in the A site of the ribosome, then the ribosome move down one codon and puts the AA carrying the polypeptide into the P site and the now-uncharged tRNA into the E site. The tRNA is ejected and a new tRNA complementary to the next codon binds to the A site. The polypeptide transfers to the AA on the tRNA in the A site and the chain is elongated by repeating all of these steps.

Question 5

Translation termination

Answer 5

Stop codon is encountered and a protein release factor binds to the A site of the ribosome and breaks the bond connected to the chain and the tRNA. This creates a carboxyl terminus of the chain and it is now completed.

Question 6

RNA polymerase reading direction

Answer 6

3’ to 5’

Question 7

How to do transcription and translation

Answer 7

Start with non-template strand (5’ to 3’) and switch the T’s to U’s. This is the pre-mRNA. To get the mature mRNA, cut out the introns and add 5’ cap and poly A tail. Next translate by starting at the 5’ AUG 3’ and get the AA’s needed until the stop codon (don’t include that AA, it does not code for one). Amino….. Carboyxl.

Question 8

Codon

Answer 8

5’ to 3’ on mature mRNA

Question 9

Anticodon

Answer 9

On tRNA that codes it to pick up the specific AA - complementary and antiparallel to mRNA

Question 10

Rho independant termination in prokaryotes

Answer 10

complentary sequens on same line and chain of U’s form hairpin

Question 11

Rho dependent termination in prokayotes

Answer 11

mRNA contaions bases called Rut site that give a site where Rhode Island protein can bind and end trasncription

Question 12

RNA P 1

Answer 12

Large rRNA

Question 13

RNA P 2

Answer 13

Pre-mRNA, snRNA, snoRNA, miRNA

Question 14

RNA P 3

Answer 14

tRNA, small rRNA, some snRNA, some miRNA

Question 15

TFDII

Answer 15

binds to TATA box and recruits transcription machinery

Question 16

TBP

Answer 16

binds to TATA box and recruits transcriptuon macheines - similar dunction to sigma factor in prokaryotes for eukaryotes

Question 17

TFHII

Answer 17

initial unwinding of DNA and phosphorylation of CTD

Question 18

Degenerate Code

Answer 18

Amino acid may be specified by more than one codon
Can also be referred to as redundancy

Question 19

Isoaccepting tRNAs

Answer 19

different tRNAs that accept the same amino acid but have different anticodons