Transcript RNA

RNA
Chapter 10.2
Structure of RNA
Ribose- the sugar molecule of every RNA
nucleotide
Uracil- nitrogen-containing pyrimidine
base (replaces thymine)
Uracil pairs with adenine in RNA
Types of RNA
Messenger RNA (mRNA)- consists of
RNA nucleotides in the form of a single
uncoiled chain
Carries genetic information from DNA in
the nucleus to the cytosol
Transfer RNA (tRNA)- consists of a single
chain of about 80 RNA nucleotides in a
hairpin shape
Binds to specific amino acids
45 varieties
Ribosomal RNA (rRNA)- most abundant
form of RNA
Consists of globular RNA nucleotides
Makes up the ribosomes where proteins
are made
Transcription
Transcription- the process by which
genetic information is copied from DNA to
RNA
RNA polymerase binds to the promoter of
a specific gene
A complimentary copy of the DNA base
sequence is made
Steps of Transcription
RNA polymerase- the primary
transcription enzyme
Synthesizes RNA copies of specific
sequences of DNA
Promoters- specific regions of DNA where
RNA polymerase binds to
Marks the beginning of a single gene
When RNA polymerase binds to DNA, the
DNA separates and one side acts as a
template
Termination signal- a specific sequence
of nucleotides that marks the end of a
gene
At a termination signal, RNA polymerase
releases the DNA and the newly formed
RNA molecule
Products of Transcription
Transcripts- the different types of RNA
molecules
Instructions for making a protein are
copied from DNA to mRNA