Transcription and Translation

Question 0

Template strand

Answer 0

Strand of DNA that gene is transcribed from

Question 1

mRNA

Answer 1

Carries message to be translated

Question 2

Codon

Answer 2

3 nucleotides that code for a specific amino acid
Complementary to RNA strand
Read in 5’ to 3’ direction

Question 3

Redundancy

Answer 3

Several codons for 1 amino acid

Question 4

Ambiguity

Answer 4

1 codon only codes for 1 amino acid

Question 5

Initiation (transcription)

Answer 5

1st step of transcription
RNA pol binds to promoter
DNA unwinds
RNA pol initiates RNA synthesis at start point on template strand

Question 6

Elongation (transcription)

Answer 6

2nd step of transcription

RNA pol unwinds DNA and elongates RNA transcript in 5’ to 3’ direction

Question 7

Termination (transcription)

Answer 7

3rd step in transcription
RNA transcript is released
RNA pol detaches from DNA

Question 8

Promoter sequence

Answer 8

Sequence of DNA that binds to transcription factors

Question 9

Transcription factors

Answer 9

Group of proteins that bind to promoter sequence

Signal RNA pol II to come over

Question 10

Polyadenylation Sequence

Answer 10

Eukaryotes- signals end of transcription
10-35 nucleotides later, pre mRNA is cut free from RNA pol II
RNA pol II continues to transcribe for hundreds more nucleotides until it falls off

Question 11

Terminator sequence

Answer 11

Prokaryotes- sequence of DNA that stops transcription

Question 12

RNA processing

Answer 12

5’ cap: modified guanine
Poly-A tail: 50-250 adenines are added to 3’ end
5’ and 3’ untranslated regions
Facilitate transportation of mRNA from nucleus
Protect mRNA from degradation by hydrolytic enzymes
Ribosomes recognize 5’ cap and bind to it

Question 13

Introns

Answer 13

Intervening sequences of RNA that are removed

Non coding segments

Question 14

Exons

Answer 14

Portions of RNA that code for amino acids

Translated into protein

Question 15

Spliceosome

Answer 15

Glues exons together

Question 16

sRNA

Answer 16

Connects to and recruits more proteins
Cuts out introns
Fuses exons

Question 17

tRNA

Answer 17

Picks up amino acids from cytoplasm and brings them to ribosome
Contains specific anticodon sequence for each amino acid

Question 18

Aminoacyl tRNA synthetase

Answer 18

Joins amino acids to the correct tRNA

Question 19

Ribosomes

Answer 19

Constructed of proteins and rRNA (ribosomal RNA)

Made in nucleus, then exported to cytoplasm

Question 20

A Site

Answer 20

Aminoacyl- tRNA

Holds “charged” tRNA

Question 21

P Site

Answer 21

Peptidyl tRNA
Peptide bond is made
Holds tRNA with growing peptide chain

Question 22

E site

Answer 22

Exit site

tRNA leaves

Question 23

Initiation (translation)

Answer 23

1st step of translation

Small ribosomal subunit binds to mRNA and initiator tRNA, which carries methionine

Question 24

Elongation (translation)

Answer 24

2nd step of translation
Anticodon of tRNA binds with complementary mRNA in A site
rRNA molecule of large subunit catalyzes formation of peptide bond
Translocation of tRNA from A site to P site

Question 25

Termination (translation)

Answer 25

3rd step of translation
Stop codon is reached
Release factors cause addition of water molecule instead of an amino acid
Reaction hydrolyzes completed polypeptide and releases it