Stormy evening

The second lecture was on regulation of gene expression. Our class was this evening, started at 3 pm because we went to NUCEL at SACC. The weather was definitely suitable for us to stay on our bed. But yeah, it was a bit stormy, and scary. Still, the class continued haha. 

Two types of modes of gene expression – Constitutive expression ( expressed at the same rate at all times) and inducible expression (in response to conditions.

Two types of regulation in cell – regulation of enzyme activity (feedback inhibition, allosteric inhibition) and regulation of enzyme synthesis ( gene expression, transcription ofmRNA – repression & induction).

Repressor blocks transcription and activator encourages transcription

For try Operon, when there is no tryptophan, the inactive repressor stay inactive, hence transcription will occur. When there is tryptophan, it will bind to the inactive repressor making it to be active. So the transcription is blocked.

For lac operon, when there is no lactose, it can’t bind to the active repressor in order to make it inactive, so the transcription process is OFF. But if there is lactose, lactose will bind to it and transcription process is ON.

Eventho it was raining outside, we managed to finish the lecture in an hour only! Well yeah, who doesn’t like class that ends early hehehe miss you Dr Wan!