DNA to protein

Question 1

structural genes

Answer 1

encode the amino acid sequence of a polypeptide

Question 2

bacterial promoter

Answer 2

provides the site to begin transcription; site for RNA polymerase binding

Question 3

transcription factors

Answer 3

recognizes base sequences in the DNA and controls transcription

Question 4

ribosomal binding site

Answer 4

provides a location for the ribosome to bind and begin translation

Question 5

transcription initiation

Answer 5

transcription factors binding to promoter site and enables RNA polymerase to bind and an open complex is formed

Question 6

transcription synthesis/elongation

Answer 6

RNA polymerase moves along DNA in open complex to synthesize RNA

Question 7

transcription termination

Answer 7

terminator is reached that causes RNA polymerase and RNA transcript to dissociate from DNA

Question 8

transcriptional start site

Answer 8

first base used as a template for RNA transcription and is denoted +1

Question 9

Pribnow box

Answer 9

the -10 region in the bacterial promoter region with 5’-TATAAT-3’ as DNA sequence

Question 10

bacteria sequence elements

Answer 10

two portions essential for promoter region is -35 and -10

Question 11

RNA polymerase core enzyme

Answer 11

five subunits associate to form RNA polymerase and catalyze the synthesis of RNA

Question 12

RNA polymerase holoenzyme

Answer 12

Association of the RNA polymerase core enzymes and sigma factor (recognizes the promoter)

Question 13

sigma factor release

Answer 13

after the unwinding occurs at the -10 region, sigma factor is released and then transitions to the elongation phase of transcription

Question 14

RNA synthesis

Answer 14

nucleoside triphosphates are used as precursors and pyrophosphate is released

Question 15

rho dependent termination

Answer 15

a rho protein produces a stem loop structure and RNA dissociates

Question 16

intrinsic termination

Answer 16

rho independent termination; two sequences begin the stem loop and NusA causes stopping of transcription and RNA is removed

Question 17

RNA polymerase I

Answer 17

transcribes all of the genes that encode ribosomal RNA except for 5S RNA

Question 18

RNA polymerase II

Answer 18

major role in cellular transcription because it transcribes all the structural genes

Question 19

RNA polymerase III

Answer 19

transcribes all tRNA genes and the 5S rRNA gene

Question 20

core promoter

Answer 20

eukaryotic promoter region with TATA box at -25 and transcriptional start site

Question 21

basal transcription

Answer 21

core promoter produces a low level of transcription

Question 22

eukaryotic regulatory elements

Answer 22

affect the ability of RNA polymerase to recognize the core promoter and begin the process of transcription

Question 23

cis-acting elements

Answer 23

DNA sequences such as TATA box, enhancers, and silencers exert their effects over a particular gene; always on the same chromosome

Question 24

trans-acting elements

Answer 24

regulatory transcription factors that bind to the cis-acting elements

Question 25

general transcription factors

Answer 25

there are 5 different proteins always needed for RNA polymerase II to initiate transcription of structural genes

Question 26

chromatin remodeling

Answer 26

either histone acetyltransferases or ATP dependent chromatin remodeling opens DNA from its winding of histones

Question 27

nucleolus

Answer 27

ribosomal subunits are assembled 45S rRNA is processed

Question 28

pre-mRNA

Answer 28

heterogeneous nuclear RNA (hnRNA); transcription of structural genes produces a long transcript that must undergo splicing of introns before exiting the nucleus

Question 29

spliceosome

Answer 29

large complex of snRNPs that splices the introns in pre-mRNA in the nucleus of eukaryotes

Question 30

snRNPs

Answer 30

small nuclear ribonucleoproteins; composed of small nuclear RNA and a set of proteins

Question 31

alternative splicing

Answer 31

two or more different proteins can be derived from a single gene with different exons being chosen

Question 32

5' cap

Answer 32

a 7-mylguanosine is covalently attached for the proper exit of most mRNA from nucleus and translation

Question 33

polyA tail

Answer 33

a string of adenine nucleotides are added enzymatically to the 3' end in a process called polyadenylation

Question 34

sense codons

Answer 34

sequence of 3 bases in most codons specifies a particular amino acid

Question 35

start codon

Answer 35

AUG specifies methionine as usually first codon of polypeptide

Question 36

anticodons

Answer 36

3 nucleotide sequences of tRNA that are complementary to mRNA codons

Question 37

polypeptide-amino acid

Answer 37

polypeptides are composed of 20 different kinds of amino acids, so at least 20 codons are needed for each amino acid

Question 38

codon system

Answer 38

there is a 3 base codon system that produced 64 potential different codons

Question 39

degenerate genetic code

Answer 39

since only 20 different codons are needed, but there are 64 different potentials, more than one codon can specify same amino acid

Question 40

peptide formation

Answer 40

condensation reaction forms bond; the beginning of the polypeptide has amino group exposed and the ending has carboxyl group exposed

Question 41

primary structure

Answer 41

the polypeptide sequence

Question 42

secondary structure

Answer 42

alpha helix and beta sheets with hydrogen bonds

Question 43

tertiary structure

Answer 43

folding with hydrophobic, ionic, hydrogen, van der waals, and disulfide bonding

Question 44

quaternary structure

Answer 44

two or more polypeptides

Question 45

adaptor hypothesis

Answer 45

the anticodon in a tRNA specifies the type of amino acid it carries

Question 46

aminoacyl-tRNA synthetase

Answer 46

20 different aminoacyl-tRNA synthetases that catalyze the covalent bonding of the amino acid to tRNA

Question 47

aminoacyl tRNA

Answer 47

charged tRNA that has the amino acid attached to the 3' end

Question 48

isoacceptor tRNA

Answer 48

two or more tRNA that differ at the wobble base are able to recognize the same codon

Question 49

translation: initiation

Answer 49

ribosomal subunits, mRNA, and first tRNA assemble into a complex

Question 50

translation: elongation

Answer 50

ribosome slides in 5'-3' direction and tRNA molecules bind to the mRNA; amino acids are linked together

Question 51

translation: termination

Answer 51

stop codon is reached and disassembly occurs

Question 52

Shine-Dalgarno sequence

Answer 52

the ribosomal binding site for bacteria where mRNA and ribosomes bind together

Question 53

translation-initiator tRNA

Answer 53

in archaea and eukaryotes carries a methionine; in bacteria methionine has been covalently modified to N-formylmethionine

Question 54

translation-initiation site

Answer 54

tRNA fmet enters at the p site

Question 55

translation-elongation stage

Answer 55

tRNA enters at the A site

Question 56

peptidyl transfer

Answer 56

polypeptide is transferred from the P site to the A site by peptidyltransferase; ribosome then moves one codon to the right

Question 57

translation-termination

Answer 57

stop codons are recognized by released factors and not by tRNA

Question 58

bacterial coupling

Answer 58

a ribosome attaches to the 5' end of mRNA and starts translation before transcription ends

Question 59

polyribosome

Answer 59

an mRNA transcript that has many bound ribosomes in the act of translation