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RNA transcription Notes
Biology Honors 2015
RNA
Ribonucleic Acid
RNA Structure
• Composed of nucleotides
P
Sugar
Base
RNA Structure
• Bases: Uracil Replaces Thymine
A = U (Uracil)
C=G
DNA A T C G A C A A T T C G
mRNA U A G C U G U U A A G C
RNA
DNA
“Deoxy”
RNA Structure
• Single Stranded
(only one strand)
RNA Transcription
Textbook Definition:
First stage of protein synthesis. An RNA
stand is assembled on exposed bases of
an unwound strand of a DNA double helix.
Transcription = the process of
building an RNA copy of a DNA
sequence.
DNA replication vs. RNA transcription
• RNA is single stranded
• U replaces T in RNA
• RNA Transcription
only happens in small
sections (one gene).
DNA replication
copies the whole
strand.
• DNA stays in the nucleus and RNA leaves the
nucleus and travels into the cell.
6 Steps of Transcription
1. Enzyme untwists the
DNA and starts
transcription
2. Enzyme unzips DNA
(transcription bubble)
3. Free RNA nucleotides
base pair w/ DNA
A=U
C=G
4. RNA nucleotides bond
together at the backbone
5. New single strand RNA
detaches from DNA template
6. Enzyme closes (re-zips) and
twists DNA
Process of Protein Synthesis