E. coli  contains three lactate dehydrogenases.  One is used to ferment pyruvate to lactate and the other two are used as electron donors in aerobic respiration.

    1. Name the genes encoding the three lactate dehydrogenases and state what process the enzyme is involved in.

 

 

    1. The lldD gene is part of an operon. Which other genes are present and what is the function of their gene products?

 

 

  1. Under what environmental conditions is lldD repressed?  What protein(s)/molecule(s) repress its expression?