Unit 6 - topic 4

Question 1

translation

Answer 1

synthesis of a polypeptide using information from the mRNA

Question 2

a nucleotide sequence becomes

Answer 2

an amino acid sequence

Question 3

tRNA is a key player in

Answer 3

translating mRNA to an amino acid sequence

Question 4

transfer RNA

Answer 4

has an anticodon region which is complementary and antiparallel to mRNA

Question 5

tRNA carries

Answer 5

the amino acid that the mRNA codon codes for

Question 6

enzyme aminoacyl-tRNA synthetase is responsible for

Answer 6

attaching amino acids to tRNA

Question 7

when tRNA carries an amino acid it is

Answer 7

“charged”

Question 8

translation occurs at the

Answer 8

ribosome

Question 9

ribosomes have two subunits

Answer 9

small and large

Question 10

prokaryote subunit

Answer 10

small subunit (30s) large subunit (40s)

Question 11

eukaryote subunit

Answer 11

small subunit (40s) large subunit (60s)

Question 12

large subunit has three sites

Answer 12

A, P, and E

Question 13

A site

Answer 13

amino acid site
holds the next tRNA carrying an amino acid

Question 14

P site

Answer 14

polypeptide site
holds the tRNA carrying the growing polypeptide chain

Question 15

E site

Answer 15

exit site

Question 16

initiation

Answer 16

• small ribosomal subunit binds to the mRNA and a charged tRNA binds to start codon AUG on mRNA
• tRNA carries methionine
• large subunit binds

Question 17

elongation

Answer 17

• next tRNA comes into A site
• mRNA is moved through ribosome and its codons are read
• each mRNA codon codes for a specific amino acid
• codon charts are used to determine amino acid

Question 18

common ancestry

Answer 18

idea that all organisms use the same genetic code

Question 19

elongation steps order

Answer 19

codon recognition
peptide bond formation
translocation

Question 20

codon recognition

Answer 20

appropriate anticodon of next tRNA goes to A-site

Question 21

peptide bond formation

Answer 21

peptide bonds are formed that transfer the polypeptide to A site tRNA

Question 22

translocation

Answer 22

tRNA in A site moves to P site, tRNA in P site goes to E site. A site is open for next tRNA

Question 23

termination

Answer 23

• termination occurs when a stop codon in the mRNA reaches the A site of the ribosome
• stop codons do not code for amino acids
• stop codon signals for a release factor

Question 24

release factor

Answer 24

• hydrolyzes bond that holds the polypeptide to P site
• polypeptide releases
• all translational units disassemble

Question 25

primary

Answer 25

chain of amino acids

Question 26

secondary

Answer 26

coils and folds due to hydrogen bonds forming

Question 27

tertiary

Answer 27

side chain interaction

Question 28

quaternary

Answer 28

2+ polypeptide chains interacting

Question 29

protein folding

Answer 29

as translation takes place, growing polypeptide chain begins to coil and fold

Question 30

genes determine

Answer 30

primary structure

Question 31

primary structure determines

Answer 31

final shape

Question 32

some polypeptides require

Answer 32

chaperone proteins to fold correctly and some require modification before it can be functional in cell

Question 33

retroviruses

Answer 33

retroviruses, like HIV, are an exception to the standard flow of genetic information

Question 34

information flows from

Answer 34

RNA to DNA
uses an enzyme known as reverse transcriptase

Question 35

reverse transcriptase

Answer 35

couples viral RNA to DNA
DNA then becomes part of RNA