1. What is the function of the cell membrane? 2. Explain how the cell membrane maintains homeostasis.

Proteins in the cell membrane include cell-surface markers, receptor proteins, enzymes, and transport proteins.

One is to transport nutrients into the cell and also to transport toxic substances out of the cell.

Explanation: I hope this helps

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.