CH12- Transcription & Translation; Mutations

Question 1

transcription

Answer 1

mechanism by which the information encoded in DNA is made into complementary RNA copy

Question 2

translation

Answer 2

use of information encoded in the RNA to assemble amino acids into a polypeptide

Question 3

transcription factors

Answer 3

protein that recognizes and binds to the TATA box and then recruits the polymerase

Question 4

mRNA (messenger RNA)

Answer 4

RNA molecule that serves as a template for protein synthesis

Question 5

RNA polymerase

Answer 5

enzyme that catalyses the assembly of nucleotides into an RNA strand

Question 6

transcription unit

Answer 6

region of DNA that transcribes a single primary transcript

Question 7

promoter

Answer 7

site to which RNA polymerase binds for initiating transcription of a gene

Question 8

terminator sequence

Answer 8

sequence for a gene that signals the end of transcription of a gene

Question 9

pre-mRNA (precursor mRNA)

Answer 9

primary transcript of a protein-coding gene, which is process to form mRNA

Question 10

5’ cap

Answer 10

a guanine-containing nucleotide attached in a reverse orientation to the 5 end of pre-mRNA and retained in the mRNA produced from it. The site where ribosomes attach to initiate translation

Question 11

poly(A) tail

Answer 11

string of A nucleotides added post-transcriptionally to the 3’ end of a pre-mRNA molecule and retained in the mRNA produced, that enables the mRNA to be translated efficiently and protects it from attack by RNA-digesting enzymes

Question 12

introns

Answer 12

a non-protein-coding sequence that interupts the protein-coding sequence

are removed by splicing in the processing of pre-mRNA to mRNA

Question 13

exons

Answer 13

an amino acid-coding sequence in pre-mRNA that is retained in a spliced mRNA that is translated to produce a polypeptide

Question 14

ribozymes

Answer 14

an RNA-based catalyst

Question 15

splicesome

Answer 15

complex formed between pre-mRNa and sRNPs, in which mRNA splicing takes place

Question 16

snRNPs

Answer 16

complex of RNA and proteins

Question 17

ribosomal RNA

Answer 17

RNA component of riboomes

Question 18

snRNAs

Answer 18

uhh

Question 19

triplet code/codons

Answer 19

each three-letter word of genetic code

Question 20

sense codon

Answer 20

a codon that specifies an amino acid

Question 21

stop/nonsense codon/termination codon

Answer 21

a codon that does not specify amino acids. (UAG, UAA, UGA)

Question 22

start/initiator codons

Answer 22

the first codon read in an mRNA in translation (AUG)

Question 23

anticodons

Answer 23

three-nucleotide segment in tRNAs that pairs with a codon in mRNAs

Question 24

P site

Answer 24

the site in the ribosome where the tRNA carrying the growing polypeptide chain is bound

Question 25

E site

Answer 25

site wher an exiting tRNA binds prior to its release from the ribosome

Question 26

A site

Answer 26

site where the incoming aminoacyl-tRNA carrying the next amino acid to be added to the polypeptide chin binds to the mRNA

Question 27

elongation factors

Answer 27

proteins that promote various steps in the elongation of peptides during translation

Question 28

release factor/temrination factor

Answer 28

a protein that recognizes stop codons in the A site of a ribosome translating an mRNA and terminates translation

Question 29

polysome

Answer 29

the entire structure of an mRNA molecule and the multiple associated ribosomes that are translating it simultaneously

Question 30

signal peptide

Answer 30

short segment of amino acids to which the signal recognition particle binds, temporarily blocking further translation. Found on polypeptides that are sorted to the ER

Question 31

point mutation

Answer 31

mutation that only affects one nucleotide

Question 32

base-pair subsitution

Answer 32

A type of mutation involving replacement or substitution of a single nucleotide base with another in DNA or RNA molecule

Question 33

silent mutation

Answer 33

a base-pair substitution mutation in a protein-coding gene that does not alter the amino acid specified by the gene

Question 34

missense mutation

Answer 34

a base-pair substitution mutation in a protein-coding gene that results in a different amino acid in the encoded polypeptide than the normal one

Question 35

nonsense mutation

Answer 35

a base-pair mutation in a gene in which the base-pair change results in a change from a sense codon to a nonsense codon in the mRNA the polypeptide translated from the mRNA is shorter than the normal polypeptide bc of the mutation

Question 36

frameshift mutation

Answer 36

mutation in a protein-coding gene that causes the reading frame of an mRNA transcribed from the gene to be altered, resulting in the production of a different, non-functional, amino acid sequence in the polypeptidr

Question 37

insertion

Answer 37

addition of another base-pair into a DNA sequence

Question 38

deletion

Answer 38

removal of another base-pair into a DNA sequence

Question 39

frameshift mutation

Answer 39

mutation in a protein-coding gene that causes the reading frame of an mRNA transcribed from the gene to be altered, resulting in the production of a different, non-functional, amino acid sequence in the polypeptide