The correct answer here is "cell membrane". Generally it makes sure that nothing enters or leaves the cell, except by its highly guarded "gates", such as ion channels, that let some particles through - but they're very picky about whom to let in!
Answer:
C
Explanation:
essential amino acids cannot be synthesized within the human body . so they have to be taken outside from foods. ( in human)
but non essential amino acids are synthesized in the liver using essential amino acids.
person has to obtain first class proteins such as meat , egg , soya protein in order to get essential amino acids.
but plants synthesize both essential and non essential amino acids within their bodies.
a person needs both essential and nonessential amino acid for his/her function
hope you understood this part :p
