Well, to put it to the simplest way I can get it. Protein acts as a car engine because it gives us the energy to go and do things like a car engine gives a car the will to move.
Answer:
Proteins is a macromolecule that helps to send signals
The deer eat grass. Its droppings, which eventually decompose into the ground, provide minerals and vitamins to the plant roots. This food is vital for it so the plant remains alive and can produce oxygen which is essential for the deer and grass is also a food source for him too.
