Is it harder to breath in space then on Earth?

Question: Is it harder to breath in space then on Earth?
- Keywords:
  breathing
Asked by Jay Pinkney to Steve, Shefali, Kevin, Katie, Jean-François, Floris, Delma, Claudie on 1 Feb 2016. This question was also asked by kayleighxox.
- Claudie Haignere answered on 1 Feb 2016:
  
  In the station itself, the atmosphere is the same than on earth.

Question: Is it harder to breath in space then on Earth?