True, depending on which isotope. some Isotopes are deemed extremely unstable and cannot be used for nuclear fuel. however, most are usable
I believe this represents the goal of not doubting anything in science. Paleontologists found a species that was previously known to be extinct, which means that there could be many more discoveries like this that could change history as we know it. I bet this taught scientists to not have a fixed mindset when it comes to searching for more answers on a topic.
I hope I helped!
Answer:
carrier proteins (embedded in the plasma membrane)