What component of amino acid structure varies among different amino acids?

Answer

The components of the r group of amino acid structure varies among different amino acids

Explanation  

As the functional group for amino acids is as:  

R-CH-COOH  

 I  

NH2  

only R differs so amino acids also differs. If R is “H” then amino acid is glycine and if R is “CH3” then amino acid is alanine. Hence, R is different for different amino acids. Other components as alpha carbon ( C ), carboxyl group ( COOH ) and amino group ( NH2 ) is fixed for every amino acid.  

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.