Protein Synthesis

Question 1

Who cracked the genetic code?

Answer 1

Nirenburg

Question 2

Characteristics of the genetic code

Answer 2

1. Triplet code of 3 nucletides
2. Code is comma free
3. The code is nonoverlapping
4. Nearly universal
5. Code is degenerate-ore than one codon occurs for each amino acid
6. start and stop codon

Question 3

What are the 3 stop codons?

Answer 3

1. UAA
2. UAG
3. UGA

Question 4

What is the start codon?

Answer 4

AUG-methionine

Question 5

What is a point mutation?

Answer 5

Chemical change in just one base pair of a gene

Question 6

What are the 2 types of small-scale mutations?

Answer 6

1. Nucleotide-pair substitutions
2. One or more nucleotide-pair insertions or deletions

Question 7

Silent mutation

Answer 7

No effect on amino acid due to the redundancy in genetic code

Question 8

Missense mutations

Answer 8

Still code for an amino acid-but not the correct one

Question 9

Nonsense mutations

Answer 9

Change an amino acid codon into a stop codon-leads to a nonfunctional protein

Question 10

What can insertions and deletions cause regarding the reading of genetic code?

Answer 10

Frameshift mutation

Question 11

What is an anticodon?

Answer 11

The sequence of three nucleotides that base-pairs with a codon in mRNA

Question 12

What is the enzyme that matches a tRNA to an amino acid?

Answer 12

Aminoacyl-tRNA synthetase

Question 13

What are the two subunits that make up a prokaryote ribosomes?

Answer 13

30s, 50s, 70s

Question 14

What are the two subunits that make up eukaryotic ribosomes?

Answer 14

40s, 60s, 80s

Question 15

What are the 3 binding sites on tRNA?

Answer 15

“EPA” left-to-right
E-exit site where discharged tRNAs leave the ribosome
P-Holds the tRNA that carries the growing polypeptide chain
A-tRNA that carries the next amino acid to be added to the chain

Question 16

What is involved in the initiation stage of building a polypeptide?

Answer 16

1. mRNA
2. tRNA
3. First amino acid
4. 2 ribosomal subunits