Chapter 39: The Genetic Code (Test 1)

Question 1

What kind of RNAs function as catalysts?

Answer 1

• Ribozymes

Question 2

What do group 1 introns require as a co-factor?

Answer 2

• Guanosine

Question 3

What does protein biosynthesis require?

Answer 3

• Ribosomes
• mRNA
• tRNA
• Protein factors

Question 4

What activates amino acids?

Answer 4

• tRNA and aminoacyl-tRNA synthetases (an ester linkage)

Question 5

What encodes an amino acid?

Answer 5

• 3 nucleotides called a codon

Question 6

What does it mean to be degenerate?

Answer 6

• When amino acids are encoded by more than one codon

Question 7

What is the start codon?

Answer 7

• AUG

Question 8

What does AUG code for?

Answer 8

• Methionine

Question 9

What are the stop codons?

Answer 9

• UAA
• UAG
• UGA

Question 10

What does tRNA function as?

Answer 10

• An adapter molecule between a codon and an amino acid

Question 11

What is the 3D structure of tRNA?

Answer 11

• L-shaped

Question 12

What is the 2D structure of tRNA?

Answer 12

• A cloverleaf pattern

Question 13

What are the true translators of the genetic code?

Answer 13

• Synthetases because they assign a particular amino acid to a specific tRNA

Question 14

E. coli has what kinds of ribosome and subunits?

Answer 14

• A 70S ribosome
• A large 50S subunit
• A smaller 30S subunit

Question 15

What is ubiquitinylation?

Answer 15

• When ubiquitin bonds to proteins for destruction

Question 16

What are lysosomes?

Answer 16

• an organelle in the cytoplasm of eukaryotic cells that contain degradative enzymes

Question 17

What are proteasomes?

Answer 17

• Macromolecular structures that break down proteins tagged by ubiquitin.