Topic 2 - Hormone Biosynthesis and Receptors Flashcards
Transcription
Is the 1st step of gene expression, where a particular segment of DNA is copied into RNA
- by the enzyme RNA polymerase
Splicing
Is the editing of the precursor mRNA. Introns are removed and exons are joined together
Translation
mRNA is decoded by a ribosome, outside the nucleus, to produce a specific amino acid chain or ploypeptide
Promoter
Is a region of DNA that initiates transcription of a particular gene
Enhancer
Is a short region of DNA that can be bound by proteins to increase the likelihood that transcription of a particular gene to occur
- Usually referred to as TF (transcription factor)
What do insulin and prolactin synergistically stimulate?
Beta-casein mRNA translation by cytoplasmic polyadenylation
What kind of protein is beta- casein?
Milk protein
What enzyme transcribes genes to mRNA?
RNA polymerase 2
What does transcription initiation require?
Many general and specific transcription factor protein binding promoters
Where does transcription start site usually occur?
Just after a TATA box
What do activators do?
Then bind enhancer DNA sequences and increase transcription – hormone influence
What do repressors do?
They bind silencer DNA sequences and decrease transcription – hormone influence
How do chromatin remodelling complexes weaken histone DNA interactions and DNA folding?
They use ATP-driven conformational change
HATs
Histone acetylases
What do HATs do and whats the result?
They add acetyl groups to histones resulting in more open conformation
HDACs
Histone deacetylases
HRE
Hormone response element