Lecture 12

Question 1

Unidirectional

Answer 1

Information can only go in one direction

Question 2

Gene

Answer 2

A region of DNA that is transcribed and has a function in the cell

Question 3

Promoter

Answer 3

Site of RNA polymerase assembly, DNA sequence that determines start of gene, no promoter means no gene

Question 4

TATA Box

Answer 4

AT rich sequence found 10 base pairs before transcription start

Question 5

Transcription Factors

Answer 5

Proteins that recognize and bind the TATA box, can read DNA, recruits RNA polymerase because RNA pol can’t identify promoter on its own

Question 6

Transcription

Answer 6

DNA to mRNA

Question 7

Template Strand

Answer 7

Used in transcription, runs 3’ to 5’ away from promoter

Question 8

Coding Strand

Answer 8

Complementary and antiparallel to template, runs 5’ to 3’ away from promoter, not used in transcription

Question 9

Transcript

Answer 9

mRNA product

Question 10

RNA Polymerase

Answer 10

Enzyme of transcription, part of a transcription initiation complex that assembles at the promoter, can open DNA into a transcription bubble

Question 11

UTR

Answer 11

Untranslated region, space on RNA either before translation start or after translation stop

Question 12

Elongation

Answer 12

Occurs where RNA polymerase add nucleotides 5’ to 3’ and transcript is released out of complex

Question 13

Post-transcriptional Processing

Answer 13

Eukaryotes only, occurs in nucleus, increase stability of transcript

Question 14

meG Cap

Answer 14

Methylguanosine cap, modified base, forms a 5’ to 5’ linkage with eukaryotic mRNA to hide 5’ end from exonuclease digestion

Question 15

PolyA Tail

Answer 15

Added to 3’ end of eukaryotic mRNA, delays exonuclease digestion and aids in translation initiation.

Question 16

RNA Splicing

Answer 16

Removal of intervening sequences from coding region (introns)

Question 17

Introns

Answer 17

Non-amino acid coding regions which contain intervening sequences found in a eukaryotes gene’s DNA but not in the mature mRNA

Question 18

Exons

Answer 18

Amino acid coding regions which contain expressed sequences found in both a eukaryotes gene’s DNA and in the mature mRNA

Question 19

Spliceosome

Answer 19

Complex of snRNPs, enzyme of splicing

Question 20

snRNPs

Answer 20

Protein/RNA complexes (quaternary structure) which recognize sequences at intron/exon boundaries

Question 21

Alternative Splicing

Answer 21

Mixing and matching of exons, makes similar but not identical proteins from same gene

Question 22

Translation

Answer 22

RNA to Protein

Question 23

Codon

Answer 23

3 nucleotides associated with an amino acid

Question 24

tRNA

Answer 24

Transfer RNA, functional RNA, amino acid binding region and mRNA base pairing region (anticodon), carries appropriate amino acid to ribosome

Question 25

Anticodon

Answer 25

Antiparallel and complementary to mRNA codon

Question 26

Aminoacyl tRNA Synthetase

Answer 26

Enzyme that pairs correct amino acid based on anticodon sequence, covalently links amino acid to tRNA, energy from ATP hydrolysis

Question 27

Ribosomes

Answer 27

Catalyze peptide bonds

Question 28

Large Ribosomal Subunit

Answer 28

Contains rRNA and catalytic site

Question 29

Small Ribosomal Subunit

Answer 29

Contains rRNA and recognizes and binds RBS (reads mRNA)

Question 30

RBS

Answer 30

Ribosomal binding site, prokaryote only, sequence in mRNA that is recognized by base pairing with rRNA in small ribosomal subunit

Question 31

Formyl-methionine

Answer 31

Modified amino acid, unique to prokaryotes, first amino acid of protein synthesis (found on amino terminal)

Question 32

Bind

Answer 32

Charged tRNA approaches A site and binds to the mRNA (anticodon-codon base pairing)

Question 33

Bond

Answer 33

Peptide bond forms between amino acid chain attached to tRNA 1 and amino acid on tRNA 2, peptide chain transfers to tRNA 2

Question 34

Shift

Answer 34

Ribosome shifts down that mRNA (towards 3’ end) in a 1 codon step

Question 35

Mutagens

Answer 35

Mutation causing factors

Question 36

Mutations

Answer 36

Changes to sequence in DNA

Question 37

Base-pair Substitution

Answer 37

Mutation at the DNA level, replacement of one nucleotide and its partner with another pair

Question 38

Silent Mutation

Answer 38

Mutation at the protein level, no change in primary amino acid sequence due to redundancy in genetic code

Question 39

Missense Mutation

Answer 39

Mutation at the protein level, encodes the wrong amino acid, MAY affect protein function

Question 40

Nonsense Mutation

Answer 40

Mutation at the protein level, premature stop codon, shortened protein, may affect protein structure

Question 41

Frameshift Mutation

Answer 41

Mutation at the protein level, single base pair addition or deletion that changes the reading frame of a protein

Question 42

Spontaneous Mutation

Answer 42

Error in copying of DNA sequence

Question 43

Induced Mutation

Answer 43

Exposure to mutagens