Protect the tree from animals, bugs, or other predators.
Answer:
The membrane potential is maintained in the cell due to the unequal distribution of the ions inside and outside of the cell. This membrane potential is important for the conduction of the nerve impulse.
The arrival of the stimulus triggers the action potential. The resting membrane potential is -70mV. This is maintained by the presence of potassium ions. The influx of the sodium ions result in the change in the membrane potential from -70mV to +30mV.
The plasma membrane needs lipids, which make a semi-permeable barrier between the cell and its environment. It also needs proteins, which are involved in cross-membrane transport and cell communication, and carbohydrates, which decorate both the proteins and lipids and help cells recognize each other. Hope this helps :)
