Final answer:
A mutation changing one nucleotide is called a point mutation. It can result in different types of mutations, such as silent, missense, or nonsense, with varying effects on the protein's structure and function.
Step-by-step explanation:
A mutation that changes only one small area or one nucleotide in a gene is a point mutation.
A point mutation is essentially a genetic alteration where a single nucleotide in DNA is added, deleted, or replaced by another. Often, it has less impact than larger chromosomal alterations. Types of point mutations include substitutions, insertions, or deletions that can lead to different outcomes.
A mutation that changes the codon UUU to UCU is an example of a substitution which may result in a silent, missense, or nonsense mutation. The effects of point mutations largely depend on how they change the genetic code. While silent mutations do not affect the amino acid sequence of the protein, missense mutations change one amino acid, and nonsense mutations create a premature stop codon. Moreover, if the mutation involves the insertion or deletion of nucleotides, it could cause a frameshift mutation, ultimately altering the entire downstream amino acid sequence. These mutations can be caused by errors during DNA replication or environmental factors.