How does the open-chain structure of D-fructose differ form D-glucose?

In open form, the doubly-bonded oxygen is attached to carbon 1 in glucose (making it an aldohexose)  http://en.wikipedia.org/wiki/Glucose but to carbon 2 in fructose (making it a ketohexose) http://www.elmhurst.edu/~chm/vchembook/543fructose.html . this causes the ring forms to be very different: fructose is a five atom ring, glucose a six atom ring.

   CH2OH        
            |            
      C=O        
            |            
    HO-CH        
            |            
        HC-OH      
            |            
        HC-OH        
            |            
           CH2OH  
   
    D-Fructose
Ketohexoses like fructose: http://en.wikipedia.org/wiki/Ketohexose
--------------------------
         HC=O        
            |            
        HC-OH        
            |            
    HO-CH        
            |            
        HC-OH      
            |            
        HC-OH        
            |            
           CH2OH  
   
    D-Glucose
Aldohexoses like glucose http://en.wikipedia.org/wiki/Aldohexose