Regulation of transcription and translation Flashcards Preview

A2 Biology Unit 5 > Regulation of transcription and translation > Flashcards

Flashcards in Regulation of transcription and translation Deck (6):
1

What is the movement (idk) of transcription factors?

Transcription factors move from the cytoplasm to the nucleus.
In the nucleus they bind to specific DNA sites called promoters, which are found near the start of their target genes.

2

What is the role of transcription factors?

Activators- increase the rate of transcription.
Repressors- decrease the rate of transcription.

3

How do activators work?

They help RNA polymerase bind to the start of the target gene and activate transcription.

4

How do repressors work?

They bind to the start of the target gene, preventing RNA polymerase from binding, stoping transcription.

5

How does oestrogen affect transcription?

It binds to a transcription factor called an oestrogen receptor forming an oestrogen-oestrogen receptor complex.
The complex moves from the cytoplasm into the nucleus where it binds to specific DNA sites near the start of the target gene acting as an activator OR a repressor.

6

How does siRNA affect gene expression?

Their bases are complementary to specific sections of a target genes and the mRNA thats formed from it.

In the cytoplasm siRNA and associated proteins bind to target mRNA.
The proteins cut up the mRNA into sections so it can no longer be translated.
So, the siRNA prevents the expression of the specific gene as its protein can no longer be made during translation.