RNA makes proteins

Question 1

What does mRNA direct?

Answer 1

The protein sequence

mRNA is a crucial molecule in the process of translation, where it serves as a template for synthesizing proteins.

Question 2

What are untranslated regions in mRNA?

Answer 2

Regions not implicated in protein synthesis

Question 3

What is the structure of mRNA made of?

Answer 3

Codons (3nt)

Codons are sequences of three nucleotides that correspond to specific amino acids.

Question 4

What is the start codon?

Answer 4

AUG (Methionine)

Question 5

What are the stop codons?

Answer 5

UAA, UAG, UGA

Question 6

True or False: The UAG codon can sometimes code for an extra amino acid in certain organisms.

Answer 6

True

Question 7

What determines the position of the open reading frame (ORF) in mRNA?

Answer 7

Distribution of codons

Question 8

How is the start codon determined in prokaryotes?

Answer 8

Following the Shine-Dalgarno sequence

Question 9

In eukaryotes, how is the first start codon determined?

Answer 9

First start codon encountered from the 5’ end in a Kozak context

Question 10

How do prokaryotic ribosomes initiate translation?

Answer 10

Bind to Shine-Dalgarno box of mRNA

Question 11

What type of mRNA do prokaryotes use during translation?

Answer 11

Polycistronic

Question 12

How do eukaryotic ribosomes initiate translation?

Answer 12

Bind to 5’ cap and begin at start codon

Question 13

What type of mRNA do eukaryotes use during translation?

Answer 13

Monocistronic

Question 14

What role does tRNA play in translation?

Answer 14

Decodes the transcript into a protein sequence

Question 15

What structure does tRNA have?

Answer 15

Clover shape

The clover shape allows for proper interaction with mRNA and amino acids.

Question 16

What is located at the 3’ end of tRNA?

Answer 16

Activated amino acid (CCA)

Question 17

Where is the anti-codon located in tRNA?

Answer 17

Middle loop

Question 18

What is a wobble base?

Answer 18

Inosine, a modified adenine in the anti-codon that can bond to A, C, or U

Question 19

What is the function of tRNA charging?

Answer 19

To add specific amino acids to tRNA molecules

Question 20

What is used by aminoacyl-tRNA synthetase to add amino acids to tRNA?

Answer 20

ATP (-> AMP)

Question 21

What is the function of ribosomes?

Answer 21

To form peptide bonds and translate mRNA into proteins

Question 22

What are the two ribosomal subunits made of?

Answer 22

Riboprotein subunits

Question 23

What does the large ribosomal subunit contain?

Answer 23

Peptidyl transferase

Question 24

What is the Svedberg unit (S) used for?

Answer 24

To refer to sedimentation coefficient of ribosomes

Question 25

What is the sedimentation coefficient of prokaryotic ribosomes?

Answer 25

70s

Question 26

What is the sedimentation coefficient of eukaryotic ribosomes?

Answer 26

80s

Question 27

What is the role of the A site in ribosomes?

Answer 27

Where tRNA recognizes codon on mRNA and amino acids are delivered

Question 28

What happens at the P site of the ribosome?

Answer 28

Peptide bonds form between amino acids

Question 29

What occurs at the E site of the ribosome?

Answer 29

tRNA exits

Question 30

What initiates translation in prokaryotes?

Answer 30

Small subunit binds to the Shine-Dalgarno sequence

Question 31

What is the first amino acid in bacteria?

Answer 31

N-formyl methionine

Question 32

What catalyzes the formation of peptide bonds?

Answer 32

rRNA

Question 33

What is the function of release factor proteins?

Answer 33

Enter the A site and hydrolyze the peptide-tRNA bond, freeing the polypeptide chain

Question 34

What happens to the ribosomal subunits after termination?

Answer 34

They dissociate from the mRNA strand