Can zoos help to protect endangered species?

Many people go to the zoos and see diferent animals. That's good because the children see diferent animals but are the animals a good life into their cage?And they have the sufficient space?

On the one hand, zoos are very important for the children to get an oportunity to see animals which they don't ever seen, like bears, penguins, etc. And zoos are one of the solutions to save the animals which are in extinction.
Finally and another reason is that zoos can provided a place for animals to reproduce him and don't have problems to find food, some water and a place for sleeping.

On the other hand, animal in zoos have a small artificial environment to move than in their natural habitat, and they don't have the sufficient space for walking and running. An another thing is that in zoos animals are tired to see people all the day.

Finally, In my opinion, I think zoos are good for people and are good for animals which are in extinction.