Fear not Gretchen. With the protein in the whey - I may not be 100% - because I seem to recall in the back of my old brain that ricotta is made from cooking the whey to extract protein that does not become incorporated in the main cheese.
So D-I-L is probably correct ! - will have to research it - OK researched - half and half
"Whey from acid-set cheeses cannot produce ricotta, because all of the protein has curdled out in the original cheese. Whey contains little protein, since most of it was removed during the production of the original rennet-set cheese, from which the whey resulted. This makes Ricotta production is a low yield process, considering the amount of whey required to produce it. The whey is heated, sometimes with additional acid like vinegar, to curdle out the remaining protein in the whey. The whey is heated to a near boiling temperature, much hotter than during the production of the original cheese, of which the whey is a remnant. " -from Wiki
If you make the cheese with acid (lemon juice or vinegar) then most of the protein has been incorporated in the cheese. If you make the cheese with rennet, then there will be small amounts of protein left that can be "captured" by acidifying the whey.