rRNA and tRNA processing

rRNA genes have _______ built in

redundancy

clusters of rRNA in the nucleus are called ______ _______ ________

nucleolar organizing regions

rRNA and tRNA are more _______ and _______ than mRNA

stable, longer lived

rRNA appears in _______ ________ that are 43 kb long

repeating units

humans have _______ copies of rRNA genes

400

human rRNA gene clusters are usually at the ______ of chromosomes

ends

rRNA’s and tRNA’s first appear as ________

precursors

rRNA/tRNA have sequences that must be _______

removed

vertabrate pre-rRNAs have ______, ______, and _______ sequence

28S, 18S, 5.8S

the 28S, 18S, and 5.8S sequence are located between ______ ____ __________

transcribed spacer regions

rRNA processing occurs in the ________

nucleolus

in rRNA, sequences can be __________ or ___________

transcribed, non-transcribed

transcribed sequences can be ________ or _________

imbedded, external

as rRNA is processed, it gets ________

smaller

at the end of rRNA processing, the ______ and ________ pieces are connected

28S, 5.8S

the 18S piece goes into the ________ subunit

small

the 18S and 5.8S piece goes into the _______ subunit

large

Eukaryotes process rRNA by ________ bases

modifying

snoRNP stands for _______ ________ _________

small nucleolar ribonuclear protein

Eukaryotes modify bases using ________

snoRNP

snoRNP is made using ________

snoRNA

snoRNA are _______ to the rRNA

complimentary

snoRNP’s are located at the _________

nucleolus

snoRNP's use a _________ __________ to _________ introns and exons

methylation pattern, sort

Two ribosome subunits: _________ and ________

large, small

the large subunit is _______ size

60S

the small subunit is _________ size

40S

in prokaryotes, tRNA starts as a ________ ________

large precursor

in prokaryotes, tRNA is cleaved at _____ ________

both ends

prokaryotic pre-rRNAs often contain __________ with ___________

tRNA's, 3 rRNA's

rRNA's are released from pre-rRNAS by ___________ and __________

RNase 3, RNase E

RNase 3 does __________ __________ to separate ___________ ___________

first cleavage, large rRNA's

pre-tRNA has extra ___ and ____ __________

5', 3' pieces

3/4 rRNA products come from the ________ __________

same gene

the main rRNA gene must be cut into __________ _________ to be functional

small pieces

in eukaryotes, the pieces are ________, _________, and __________

28S, 18S, 5.8S

in prokaryotes the pieces are _______, ________, and ________

16S, 23S, 5S

in prokaryotic tRNA processing __________ recognizes the ____ end of tRNA precursors

RNase P, 5'

____________ and ____________ cleave the 5' end of pre-tRNA

RNase P, RNase D

____________ cleaves the 3' end of pre-tRNA

endonuclease

____________ removes the additional bases on the ends of pre-tRNA

Rnase D

in prokaryotes, after the 3' and 5' ends are cleaved, we locate the ________ sequence on the ___ end

CCA, 3'

CCA sequence

after the CCA sequence is found or added, tRNA can be ____________

modified

we have identified more than _________ nucleotide modification identified in prokaryotic tRNA

60

____________ enzymes modify bases

multiple

research suggests that modified forms are ____________

required

tRNA structure includes ________ _________ regions

four stem-loop

tRNA structure

four consistent regions of tRNA:

acceptor stem, D loop, anticodon loop, T psi C loop

the ___________ __________ is an additional region that may or may not be present

variable loop

The acceptor stem has the _______ on the ___

CCA, 3'

the D loop has ____ ___________

D nucleotides

the anticodon loops matches with _________

mRNA

the T psi C loop contains psi, a modified __________

uracil

the variable loop varies in __________ and __________

length, presence

some tRNA’s have “_______”

introns

introns in tRNA can be located between __________ and __________ __________

anticodon, variable loop

tRNA's use the ____________ and ____________ ___________ to remove "introns"

cleavage, ligation system