Karp Ch. 11.4: Synthesis And Processing Of Messenger Rnas

Front 1

The precursors of mRNAs are represented by diverse RNAs called _______.

Back 1

heterogeneous nuclear RNA (hnRNA)

Front 2

hnRNAs are found only in the _______.

Back 2

nucleus

Front 3

hnRNAs have large _______.

Back 3

molecular weights

Front 4

_______ RNAs are degraded after a very short time.

Back 4

hn (RNAs)

Front 5

When are hnRNAs transformed into mRNAs?

Back 5

After reaching the cytoplasm.

Front 6

Which RNAs make up most of the percentage of RNAs in an eukaryotic cell?

Back 6

rRNAs and tRNAs

Front 7

RNA polymerase II is assisted by _______ to form the preinitiation complex.

Back 7

general transcription factors (GTFs)

Front 8

RNA polymerase II is assisted by general transcription factors to form the _______.

Back 8

Preinitiation complex

Front 9

How many bases is the TATA box located upstream of the initiation site?

Back 9

24-32

Front 10

The preinitiation complex of GTFs and polymerase assemble at the _______.

Back 10

TATA box.

Front 11

What is the sequence for transcription of mRNA in eukaryotic cells?

Back 11

1.) TBP (TATA binding protein), which is a subunit of TFIID, binds to the promoter.
2.) This causes a conformational change in DNA, and TFIIA and TFIIB bind.
3.) RNAPII binds and then TFIIF also binds.
4.) Lastly, TFIIIE and TFIIH binds.

Front 12

As long as _______ remains bound to the promoter, additional RNA polymerases may be able to attach for additional rounds of transcription.

Back 12

TFIID

Front 13

What is the function of TFIIA?

Back 13

It is a stabilizer and aids TBP.

Front 14

What is the function of TFIIB?

Back 14

It bridges the gap and provides a platform for RNAPII to bind to the promoter area.

Front 15

What is the function of TFIIE?

Back 15

DNA melting

Front 16

What is the function of TFIIF?

Back 16

Recruitment (sigma)

Front 17

What is the function of TFIIH?

Back 17

Helicase (unwinds double stranded DNA)

Front 18

RNA polymerase is heavily phosphorylated at the _______.

Back 18

Carboxyl-terminal domain

Front 19

_______ phosphorylation can be catalyzed by different protein kinases. TFII_______ acts as the protein kinase.

Back 19

CTD
H

Front 20

What are two factors that may limit the mRNA elongation?

Back 20

-(NELF): negative elongation factor
-(DSIB): DRB sensitive inducing factor

Front 21

What are three elongation factors that may be associated with the polymerase as it moves along the DNA?

Back 21

- (P-TEFb): CTD phosphorylation
- (SIIa): transcription elongation factor a
- (ELL): 11-19 lysine rich leukemia

Front 22

Where are mRNAs found?

Back 22

The cytoplasm

Front 23

mRNAs are attached to _______ when they are translated.

Back 23

Ribosomes

Front 24

What structures protect mRNAs as they pass into the cytoplasm from the nucleus?

Back 24

The 5' guanosone cap and 3' poly(A) tail.

Front 25

What gives mRNAs a longer half life?

Back 25

The poly(A) tail

Front 26

Eukaryotic genes contain _______, which are missing from mature mRNAs.

Back 26

intervening sequences

Front 27

The presence of genes with intervening sequences are called _______.

Back 27

split genes

Front 28

Parts of the split gene that contribute to the mature mRNA are called _______.

Back 28

exons

Front 29

Intervening sequencing are also know as _______.

Back 29

introns

Front 30

What is the first step in the addition of a 5' methylguanosine cap to a pre-mRNA?

Back 30

A triphosphatase removes the terminal phosphate group (making it a diphosphate).

Front 31

What is the second step in the addition of a 5' methylguanosine cap to a pre-mRNA?

Back 31

A guanylyltransferase adds a guanine residue in reverse orientation, forming a 5'-5' linkage.

Front 32

What is the third step in the addition of a 5' methylguanosine cap to a pre-mRNA?

Back 32

Different methyltransferases add methyl groups to the terminal guanosine cap.

Front 33

What is the role of RNA triphosphatase?

Back 33

Removes the terminal phosphate group, forming a diphosphate.

Front 34

What is the role of guanylyltransferase?

Back 34

Adds a guanine residue in a reverse orientation, forming a 5'-5' linkage.

Front 35

What is the role of RNA methyltransferase?

Back 35

Adds a methyl group to the end of the guanosine cap.

Front 36

What enzyme adds the poly(A) tail to the end of pre-mRNAs?

Back 36

poly(A)polymerase

Front 37

What is a cleavage factor that cleaves pre-mRNA?

Back 37

endonuclease

Front 38

What is the process of removing introns from a pre-mRNA?

Back 38

RNA splicing

Front 39

What is the 5' splice site?

Back 39

G/GU

Front 40

What is the 3' splice site?

Back 40

AG/G

Front 41

Where is the polypyrimidine tail located?

Back 41

Upstream of the 3' splice site.

Front 42

RNA enzymes

Back 42

Ribozymes

Front 43

What is an example of a self-splicing intron?

Back 43

Group II Intron

Front 44

What component is required in order for pre-mRNA to begin splicing?

Back 44

Small Nuclear RNAs (snRNAs)

Front 45

As each hnRNA is transcribed, it becomes associated with a _______.

Back 45

hnRNP

Front 46

Processing occurs as each intron becomes associated with a macromolecule complex called a _______.

Back 46

Spliceosome

Front 47

The spliceosome consists of _______.

Back 47

small nuclear ribonucleoproteins (snRNPs)