Question

1. what amino acid starts a protein?
2. what stops a protein?
3. a mutation is

Explanation:

1. Methionine is the amino acid encoded by the start codon (AUG) in protein synthesis, initiating polypeptide chain formation.
2. A stop codon (UAA, UAG, UGA) signals the termination of protein synthesis, causing the ribosome to release the completed protein.
3. A mutation is a change in the DNA sequence, which can alter genetic information and potentially affect protein structure/function.

Answer:

1. Methionine
2. A stop codon
3. A change in the DNA sequence