How do current models of enzyme function differ from Fischer's lock-and-key model?
a. there has been no change in our understanding of enzyme function
b. contrary to what Fischer thought, we now know that enzymes are catalysts that can catalyze multiple reactions without being consumed
c. rather than enzymes being rigid, we now believe they undergo an induced fit upon substrate binding
d. we now understand that enzyme specificity is due to binding between substrates and amino acids in an enzyme's active site