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:
From the data of pH, the type <span>and relative size of the carbon-based molecules, you can relate these to determine at which levels that a certain carbon-based molecule. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
The industrial revolution damaged our ecosystem
