What is the lysosome pH normally?

[engineeredout]

Q: When a primary lysosome fuses with a food vesicle to become a secondary lysosome:

A: its pH drops via active pumping of protons into its interior.


The explanation for the question says that the low pH is required in order to activate the digestive enzymes.

I thought the lysosome normally has a pH around 5. Does the pH have to drop even further than that, or is 5 the pH that is required to activate the enzymes? If so, does it just float around with a neutral pH the rest of the time?

Thanks.

---

Members don't see this ad.

 

[cwfergus]

Noo,

The pH of a lysosome is yes, usually around 5 which is acidic.

So these hydrolytic enzymes that are in the lysosomes, are what is keeping the pH this low. SO, when it fuses with a vesicle, it pumps it's low pH (H+s) to the vesicle, digesting it. So yes, if it fuses with a vesicle, the pH will drop in that vesicle