<span>Amino acids are the basic structural unit of all proteins. A 'free' amino acid (a single amino acid) always has:
an amino group -NH2,
a carboxyl group -COOH
a hydrogen -H
a chemical group or side chain -"R".
Since the amino acids (except glycine) have 4 different groups attached to the a-carbon, they are optically active stereoisomers (recall 23.101 Organic Chemistry) although only L-isomers are found in proteins.
At a neutral pH, both the amino and the carboxyl groups are ionised, giving what is termed the zwitterionic</span>
Not sure if you still need the answer but its number Three, they are the decomposers in many ecosystems
Answer:
mantle i believe the answer should be mantle
<u>Answer</u>: d. it will release chemical messengers.
The action potential, which is an electric pulse, will travel down the axon untill it reaches the synapses. At the synapses, neurotransmitters (chemical messengers) will be released by the neuron.