Genetics - Chapter 3

Gene Expression

Process where a gene product (RNA or Protein) is synthesized

Transcription

1st step to gene expression, where Dna is copied into RNA via RNAP

Gene

Basic unit of transcription, nucleotide sequence that has the info to code RNA or Protein

Promoter

DNA sequence indicates the start of a gene and is binding site for RNAP, determine which 2 strands will be template strand

TTGACG

-35 region

TATAAT pribnow box

-10 region

Transcription start site

+1 position where transcription begins

Consensus sequences

most frequently found nucleotides 

template strand

strand used by RNAP as template to add RNA nucleotides

complementary strand

same sequence as RNA product including U instead of T 

Cis acting elements

DNA sequences that control expression of nearby genes

Operator

cluster of genes under control of one promoter

RNA coding region

part of DNA after promoter that is copied into RNA , includes terminator sequence

transcription terminators

DNA sequence that signals transcription end -  UAA, UAG, UGA

RNAP

enzyme that synthesizes RNA

Holoenzyme

RNAP + sigma factor

Sigma factor

recognizes the promoter and helps holoenzyme attach

Transcription factors

activate/repress transcription of certain genes