Hello there!
The principle of diffusion consists in the movement of substances through a membrane from a zone with high concentration, to a zone with low concentration, until the concentration is equal on both sides of the membrane.
An example of diffusion is the process that happens when we breathe. Two substances in the body that will move based on the principles of diffusion are Carbon Dioxide and Oxygen. Carbon Dioxide will move from the bloodstream to the alveoli, and Oxygen will move from the alveoli to the bloodstream.
It would smell like death
Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
Humans obtain nitrogen by eating other organisms.
It seems That teh molecules can move towards the membrane
