関連ワード:  define primary structure class 12    define primary structure class 12th chemistry    define primary structure class 12 biomolecules    what is primary structure class 12    define primary structure of protein class 12    define primary structure of protein class 12 chemistry    what is primary structure of protein class 12    what is primary structure of protein class 12 chemistry    explain primary structure of protein class 12    define quaternary structure of protein class 12