Question

a) Is lactase production regulated pre- or post-transcription?

b) How is lactase persistence an example of gene expression?

Please go into detail about these processis.

Answer 1

Please find the answers below:

Answer a: Lactase is an enzyme translated in all prokaryotic and eukaryotic cells. The expression system of lactase has been largely studied in bacteria. The lac operon induces the expression of lactase enzyme. The lac operon is an inducible operon by nature which means that the presence of lactose in the medium upregulates the gene expression. Hence, the lac operon is regulated pre-transcription in nature.

Answer b: Lactase persistence refers to uninterrupted presence of active lactase enzyme in the body, majorly in the adults. The lactase enzyme is generally decreased in expression and activity after birth (nearly adulthood) in humans. This makes them unable to digest lactose sugar and hence make them lactose intolerant by nature. However, some populations ingest large amount of fermented dairy products in their diet which makes them able to digest the lacotse sugar and the partially fermented lactose represents as a positive regulator of lactase gene expression. This is why lactase persistence is generally observed in some populations across the globe, especially those who incorporate curd in their diet very frequently.