Chapter 5: Nucleic Acids (Translation)

Question 1

• process of protein synthesis
• involves translating genetic information from sequence of nucleotides to amino acids in the primary structure of protein

Answer 1

translation

Question 2

carries out translation

Answer 2

ribosomes

Question 3

each ribosome is made up of

Answer 3

• small subunit
• large subunit

Question 4

in eukaryotic cells, the small ribosomal subunit contains

Answer 4

• 1 rRNA
• 33 different ribosomal proteins

Question 5

in eukaryotic cells, the large ribosomal subunit contains

Answer 5

• 3 rRNA
• 49 different ribosomal proteins

Question 6

large ribosomal subunit + small ribosomal subunit

Answer 6

functional ribosome

Question 7

molecule that decodes the information in the mRNA molecule into the primary structure of a protein

Answer 7

transfer RNA

Question 8

Two function the tRNA must faithfully perform

Answer 8

1. must covalently bind one, and only one, specific amino acid
2. must recognize appropriate codon on the mRNA that calls for that amino acid

Question 9

three-nucleotide or triplet sequence found on mRNA that codes for a certain amino acid during translation

Answer 9

codon

Question 10

three-nucleotide sequence found on tRNA that binds to the corresponding mRNA sequence

Answer 10

anticodon

Question 11

cloverleaf shape of tRNA

Answer 11

three hairpin loops and one open end are present

Question 12

a tRNA molecule with antidocod 5’ AAG 3’ will interact with which of the following mRNA

Answer 12

3’ UUC 5’

Question 13

during which a complementary copy of DNA, called mRNA, is created by RNA polymerase

Answer 13

transcription

Question 14

during which a tRNA synthetase attaches the correct amino acid to the acceptor stem of the tRNA

Answer 14

tRNA activation

Question 15

protein synthesis starts with what

Answer 15

start codon

Question 16

first step of translation

Answer 16

initiation tRNA carrying amino acid Met binds at P site

Question 17

second step of translation

Answer 17

tRNA with AA 2 binds at A site

Question 18

third step of translation

Answer 18

peptide bond forms between AA 1 and 2 as AA 1 moves from P to A site

Question 19

fourth step of translation

Answer 19

• first tRNA released
• ribosome moves one codon to right translocating dipeptide to P site
• tRNA with AA 3 occupies A site

Question 20

process that advances the mRNA–tRNA moiety on the ribosome, to allow the next codon to move into the decoding center

Answer 20

translocation

Question 21

fifth step of translation

Answer 21

elongation continues as dipeptide at P site bonds to A site

Question 22

eventually the ribosome encounters a stop codon

Answer 22

termination

Question 23

the initial amino acid methionine is often __ from the beginning of the chain

Answer 23

removed

Question 24

gives the protein the final form it needs to be fully functional

Answer 24

post-translation processing

Question 25

Some aspects of post-translation processing

Answer 25

1. Methionine is removed by hydrolysis. Second hydrolysis releases polypeptide 2. covalent modification such as disulfide bridges 3. completion of folding of polypeptides

Question 26

cluster of ribosomes held together by a strand of messenger RNA that each ribosome is translating

Answer 26

polysome or polyribosome