(17+18) General RNA Synthesis and prokaryotic mRNA synthesis

Chromosomes may be divided into _ which code for a ____ product

genes; RNA

mRNA(Name)

messenger RNA

tRNA(Name)

transfer RNA

rRNA(Name)

ribosomal RNA

snRNA(Name)

small nuclear RNA.

usnRNA(Name+function)

uracil rich small nuclear RNA. associates with proteins and forms into usnRNPs which is associated with spliceosomes and cut out introns or over transcript

miRNA(Name+function)

microRNA. Regulates mRNA translation.

t/f The basic process of how DNA is used to make RNA is the same between all RNA molecules (no matter the type of RNA)

true

RNA polymerase

an important enzyme for producing RNA using a DNA template. Very large, saddle-like, multimeric enzyme.

How many types of RNA polymerase in prokaryotes?

1

How many types of RNA polymerase in eukaryotes?

3

RNA polymerase 1

responsible for transcribing large rRNA genes

RNA polymerase 2

responsible for transcribing mRNA and snRNA

RNA polymerase 3

responsible for transcribing tRNA, small (5s) rRNA and small cytoplasmic RNAs (scRNA)

What are the numbers of RNA polymerases tied to?

RNA polymerase 1 was the first one to be eluded from a column, 2 was the 2nd and 3 was 3rd. They are numbered in decreasing zie (1 is largest, 3 is smallest).

RNA polymerase is large enough to bind to [___] bp of DNA at one time

60

Promoter

series of nucleotides associated with one strand of DNA which is recognized by RNA polymerase and allows it to bind. Found in the 5’ direction of the coding strand.

Coding strand

strand of DNA with the promoter. This strand will be IDENTICAL to the produced RNA strand (with U’s instead of T’s)

Template strand

strand complementary to the DNA strand with the promoter. This is the strand used by RNA polymerase to produce an RNA molecule. This will have base pairs that are COMPLEMENTARY to the produced RNA molecule.

Upstream

towards the 5’ end

Downstream

towards the 3’ end

RNA is synthesized in the [] to [] direction

5’ to 3’

RNA polymerase moves from the [] to [] end along the DNA template strand

3’ to 5’

RNA polymerase moves from the [] to [] end along the DNA coding strand

5’ to 3’

The Coding strand of DNA is also known as the [] strand and the template strand as the [_] strand

sense; antisense

As the RNA polymerase moves forward, what does it do to the DNA structure? What happens behind the polymerase?

as it moves forward it unwinds the DNA double helix so that it may do its work. Behind it, the helix reforms.

Termination sequence

series of nucleotides on the coding strand identified by the RNA polymerase which causes it to disconnect from the DNA and stop lengthening its RNA strand. Found in the 3’ direction of the coding strand.

How is the first nucleotide of any gene labeled?

it is labeled as 1

The first nucleotide that is upstream from a gene is labeled as what?

-1

The promoter of a prokaryote is located [] from a gene and is about [] nucleotides long with [_] specific conserved sequences that are [] nucleotides long each

upstream; 35; 2; 6

Name the 2 important conserved prokaryotic sequences of its promoters and how far upstream they are from one another or the gene

TATATT box (~10 nucleotides from the gene) TTGACA (~17 nucleotides upstream of the TATATT box )

Termination sequence for RNA polymerase in prokaryotes

TTTT

What is found at the 3’ end of prokaryote RNA?

UUUU (because of the termination sequence)

t/f RNA is highly stable

false, it is very unstable

How may RNA stabilize at the 3’ end?

self complementary sequences towards the tip which form hairpin loops

Self complementary sequences

when a sequence of RNA complements itself in a different spot, allowing itself to bend and create a small region of double stranded RNA forming a hairpin loop

Hairpin loop

loop form by self complementary sequences in RNA. usually about