Describe how the r group in each of the 20 differebt amino acids determines each amino acid's characteristics

The polarity and acid/base character of each R group is the main factor determining the characteristics of an amino acid.

There are four types of R groups:

•nonpolar, e.g., CH₃ in alanine

•polar, e.g., CH₂OH in serine

•acidic. e.g., CH₂COOH in aspartic acid

•basic, e.g., CH₂(CH₂)₃NH₂ in lysine

The R group determines whether an amino acid is acidic, basic, or neutral.

However, the nature of the R groups is the major factor that determines the 2° and 3° structures of polypeptides and proteins.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.