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Flashcards in DNA to protein Deck (59)
1

structural genes

encode the amino acid sequence of a polypeptide

2

bacterial promoter

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

3

transcription factors

recognizes base sequences in the DNA and controls transcription

4

ribosomal binding site

provides a location for the ribosome to bind and begin translation

5

transcription initiation

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

6

transcription synthesis/elongation

RNA polymerase moves along DNA in open complex to synthesize RNA

7

transcription termination

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

8

transcriptional start site

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

9

Pribnow box

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

10

bacteria sequence elements

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

11

RNA polymerase core enzyme

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

12

RNA polymerase holoenzyme

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

13

sigma factor release

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

14

RNA synthesis

nucleoside triphosphates are used as precursors and pyrophosphate is released

15

rho dependent termination

a rho protein produces a stem loop structure and RNA dissociates

16

intrinsic termination

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

17

RNA polymerase I

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

18

RNA polymerase II

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

19

RNA polymerase III

transcribes all tRNA genes and the 5S rRNA gene

20

core promoter

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

21

basal transcription

core promoter produces a low level of transcription

22

eukaryotic regulatory elements

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

23

cis-acting elements

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

24

trans-acting elements

regulatory transcription factors that bind to the cis-acting elements

25

general transcription factors

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

26

chromatin remodeling

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

27

nucleolus

ribosomal subunits are assembled 45S rRNA is processed

28

pre-mRNA

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

29

spliceosome

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

30

snRNPs

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

31

alternative splicing

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

32

5' cap

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

33

polyA tail

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

34

sense codons

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

35

start codon

AUG specifies methionine as usually first codon of polypeptide

36

anticodons

3 nucleotide sequences of tRNA that are complementary to mRNA codons

37

polypeptide-amino acid

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

38

codon system

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

39

degenerate genetic code

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

40

peptide formation

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

41

primary structure

the polypeptide sequence

42

secondary structure

alpha helix and beta sheets with hydrogen bonds

43

tertiary structure

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

44

quaternary structure

two or more polypeptides

45

adaptor hypothesis

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

46

aminoacyl-tRNA synthetase

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

47

aminoacyl tRNA

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

48

isoacceptor tRNA

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

49

translation: initiation

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

50

translation: elongation

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

51

translation: termination

stop codon is reached and disassembly occurs

52

Shine-Dalgarno sequence

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

53

translation-initiator tRNA

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

54

translation-initiation site

tRNA fmet enters at the p site

55

translation-elongation stage

tRNA enters at the A site

56

peptidyl transfer

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

57

translation-termination

stop codons are recognized by released factors and not by tRNA

58

bacterial coupling

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

59

polyribosome

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