<span>I believe the answer is: D. proteins
The main functions of these proteins is to allow specific substance to pass through the membrane of the cells which needed for the energy formation for cells'functions.It created through the combination of more than 20 amino acids with different functions.</span><span />
Answer:
.........
.............tteedhhgggggfrfr
1) true
2)false
3)true
4)false
5)false
6)false
7)false
