C they increase activity of a number of neurotransmitters
Answer:
Pepsin
Explanation:
An enzyme made in the stomach that breaks down proteins in food during digestion. Stomach acid changes a protein called pepsinogen into pepsin.
I think this is an theory changing because a new scientific method was developed. They used what Mendel had learned to test the hypothesis themselves and discovered that he was right.
The thread of protien called A. Fibrinogen helps form clots.
