Gene Transcription and RNA Modification

Class 15

What is a gene? What is the first step of gene expression?

Segment of DNA that makes a functional product

• Product is RNA or protein

Transcription

What is transcription?

• process of making a copy

• end product is a messenger RNA (in a protein-coding gene)

How does transcription occur? Firstly,

PROTEINS recognize and act on DNA to transcribe

What are regulatory sequences?

• on DNA…

• Binding site for regulatory proteins → influence rate of transcription

What is a promoter?

DNA sequence

• Binding site for RNA polymerase → signals beginning of transcription

What is a terminator?

DNA sequence that signals the end of trancription

Ribosome-binding site

Guess what this means lol…

What’s being read by RNA polymerase?

The template strand (DNA)

What is the coding/sense/non-template strand?

The RNA strand that’s an identical copy of template strand except uracil replaces thymine

What are the three stages of transcription?

• Initiation

• Elongation

• Termination