Transcription

Reading DNA to make RNA.

Translation

Reading RNA into proteins.

Helicase

Sits on one of the two parental strands.

Travels in the 5' to 3' parental strand direction.

Central Dogma

DNA -> RNA -> Proteins

RNA

Single strand.

Uses Uracil instead of Thymine.

DNA

Double helix.

Transcription

Template Strand

The strand the RNA is a compliment of / built off of.

Only one of the two DNA strands is used in transcription.

RNA Polymerase

Only protein involved in transcription.

Opens up DNA strand and lays down the corresponding nucleotides for mRNA.

Always reads in the direction of promoter to terminator. Always reads in the 3' to 5' direction.

• This allows RNA synthesis to occur in the 5' to 3' direction.

Pre-RNA Primary Transcript

Is transcripted RNA before introns are taken out.

A primary transcript is the initial RNAtranscript from any gene prior to processing.

mRNA

Only contains exons.

mRNA is post-processed with introns removed.

Alignment Sheet

Aligns DNA, pre-RNA, and mRNA in one file.

Nucleotides are synced up so you can see what parts get taken off, and what parts are introns or exons.

There's no T in RNA sequences.

There's no U in DNA sequences.

Coding

Non-Coding DNA

Genes are coding regions.

Genes (exons) code for proteins.

Introns are withing genes but don't code for proteins.

Introns

These are written as an RNA strand 5'-UAUA-3'.

These are cut out of the mRNA sequence.

• Though they are included in the pre-RNA sequence.

Exons

These are written as an RNA strand 5'-UAUA-3'.

These leave the nucleus and are used for translation.

Transcription Start Site TSS

First nucleotide that gets transcribed

Promoter

Written as a DNA strand 3'-CGCG-5'.

Promoters have directionality, same as DNA.

• Read the DNA in the direction of the promoter sequence.

The promoter is exclusive (never gets transcribed).

• The first nucleotide in an RNA sequence is the one after the promoter.

Promoter and terminator exist in the template strand.

Since it only uses one DNA strand, promoter exists on one of the two DNA strands.

Terminator

Terminators have directionality, same as DNA.

The terminator is inclusive (gets transcribed).

• The terminator sequence is included in the RNA strand.

Steps

RNA is always built in the 5' to 3' direction.

Initiation

RNA Polymerase finds the promoters in a DNA sequence to identify where to start.

Elongation

Laying down RNA nucleotides.

Termination

When RNA polymerase hits the terminator sequence, it stops the transcription.

Remove the introns from your pre-RNA sequence and you have your final mRNA sequence. One gene can make many proteins depending on what RNA Polymerase reads as introns or not.