chapter 15

Question 1

proteins are composed of ___ linked together by ___ bonds.

Answer 1

amino acids

peptide

Question 2

there are 64 codons, 20 difference amino acids , and approximately 30- 50 tRNAs.

Answer 2

the 3’ base of the anticodon on the tRNA an pair weakly with the 5’ codon base

Question 3

what is the first stage of protein synthesis ?

Answer 3

tRNA charging, in which the tRNAs bind to amino acids

Question 4

which of these in not involved in the initiation of translation in bacteria?

Answer 4

tRNA carrying the next amino acid that will occupy the A site

Question 5

which does the termination of translation require?

Answer 5

release factors
GTP
stop codon on the mRNA

Question 6

a contemplate strand of bacterial DNA has the base sequence
5’ - ATGATACTAAGGCCC- 3’
determine the amino acids that will be encoded by this sequence

Answer 6

Met Ile Leu Arg Pro

Question 7

how many different mRNA sequences can encode a polypeptide. jain with the amino sequence Met-Leu-Arg?

Answer 7

number of mRNA sequences : 108

Question 8

determine the number of unique RNA sequences that encode methionine-valine- tyrosine

Answer 8

24

Question 9

determine the minim code length
species A has 2 amino acids
species B has 7 amino acids
species C had 598 amino acids

Answer 9

1
2
5

Question 10

which of the events occur during eukaryotic translation elongation?

Answer 10

A tRNA buying to codon and the ribosome ads amino acid from each tRNA to the polypeptide chain

Question 11

which event occurs during eukaryotic translation termination?

Answer 11

The ribosome dissociate from the mRNA after the stop codon is recognized by a protein

Question 12

Classify each phrase or term as relating to replication, transcription, or translation.

Answer 12

replication: both DNA strands are duplicated, described as semiconservative, & DNA polymerase
transcription: single DNA strand is used to produce mRNA
translation: amino acids added to peptide chain, requires tRNA, & ribosome

Question 13

arrange the amino acid is coded for in the translation portion of the transcription translation interactive in the correct order.

Answer 13

start
methionine
threonine
glutamine
arginine
leucine
histidine
glycine 
stop


Question 14

Suppose in assassin uses ricin, a translation inhibitor, to poison her victim. Place the events in chronological order, starting from the poisoning and ending with the death of the victim.

Answer 14

ricin enters the victims body
1. ricin is absorbed into the blood and enters the body’s cells
2. ricin binds to ribosomes in the cytoplasm
3. ricin inactivates the 28S rRNA in the large subunit of the ribosome
4. ribosomes see unable to add new amino acids to polypeptides
5. protein synthesis halts in many tissues
6. multiple organ systems fail
the victim dies