What are calories used for?

hurry pls!

Imagine that you have produced several versions of lactase, each of which differs from normal lactase by a single amino acid. describe a test that could indirectly determine which of the versions significantly alters the three-dimensional shape of the lactase protein.

Nuclear fusion is the source of energy for stars. besides hydrogen, which other element is most likely also common in stars?

The first element on the periodic table of elements is carbon. a. true b. false