Life prefers to use glucose over other sugars

[biophysics]

We learned that life prefers to use glucose over other sugars (catabolite repression).

1) Why is glucose preferred?

2) Why do sperm use fructose instead of glucose?

 

[flyingheadlice]

Hmm I know that fructose is metabolized without insulin...is this for a bio class or for an ochem class?