Keyword Analysis & Research: why are there only 20 amino acids

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
why are there only 20 amino acids	1.82	1	9323	31	33
why	1.75	0.6	5834	42	3
are	0.92	0.2	9525	65	3
there	1.46	0.5	9245	38	5
only	1.36	0.5	4486	28	4
20	0.07	0.4	2772	94	2
amino	1.16	0.9	7389	38	5
acids	0.22	0.1	2803	20	5

Keyword	CPC	PCC	Volume	Score
why are there only 20 amino acids	1.49	1	7005	30
why only 20 amino acids	0.34	0.8	6954	83
why do we only have 20 amino acids	1.06	0.4	9775	10
are there only 20 amino acids	1.29	0.3	1301	58
are there 20 or 21 amino acids	0.88	0.6	91	43
are there 20 or 22 amino acids	1.72	0.3	4004	45
what makes the 20 amino acids different	0.74	0.9	4971	72
amino acids all 20	1.83	0.5	7268	76
what makes the 20 amino acid unique	1.51	0.1	2020	69
20 common amino acids	0.62	0.6	1672	38
what differs between the 20 amino acids	0.7	0.1	5033	78
the 20 essential amino acids	0.34	0.9	1804	95