The difference between a dipeptide and a polypeptide?

Which of these statements best describes the st. lawrence seaway? the st. lawrence seaway connects the st. lawrence river with the arctic ocean. the st. lawrence seaway provides an important trading route between the u. s. and mexico. the st. lawrence seaway provides an important trading route for the u. s, but has little value for canada. the st. lawrence seaway connects the great lakes, the st. lawrence river, and the atlantic ocean.

In each transformation of energy , some energy what?

Which of these is one of the nitrogenous bases in dna? a. proline b. leucine c. glycine d. thymine