Alteration of the sequence of bases in DNA can alter the structure of proteins Flashcards
What is meant by the sequence of bases in DNA?
The sequence of bases in DNA refers to the order of nitrogenous bases (adenine, thymine, cytosine, and guanine) that form the genetic code, determining the synthesis of proteins.
How does a change in the sequence of bases in DNA affect the protein produced?
A change in the sequence of bases (a mutation) can alter the amino acid sequence in a protein, which may affect the protein’s structure and function.
What is a mutation?
A mutation is a change in the sequence of DNA bases that can lead to changes in the structure of proteins. Mutations can be caused by errors in DNA replication or environmental factors.
How do mutations affect the structure of proteins?
Mutations can result in a different amino acid sequence in a protein, which can alter the folding of the protein and potentially affect its function, stability, or activity.
What are point mutations?
Point mutations are changes in a single base pair in the DNA sequence, which can result in silent mutations, missense mutations, or nonsense mutations.
What is a silent mutation?
A silent mutation is a change in the DNA sequence that does not alter the amino acid sequence of the protein due to the redundancy in the genetic code.
What is a missense mutation?
A missense mutation is a change in the DNA sequence that results in a different amino acid being incorporated into the protein, which may alter the protein’s structure and function.
What is a nonsense mutation?
A nonsense mutation is a change in the DNA sequence that creates a premature stop codon, leading to a truncated, often nonfunctional protein.
What is a frame-shift mutation?
A frame-shift mutation occurs when nucleotides are inserted or deleted from the DNA sequence, which shifts the reading frame and alters the entire amino acid sequence downstream.
How does a frame-shift mutation affect protein function?
A frame-shift mutation can lead to a completely altered protein structure, as it changes the sequence of amino acids, which may disrupt the protein’s function.
How do environmental factors influence mutations?
Environmental factors such as radiation, chemicals, or UV light can increase the rate of mutations by causing changes in the DNA sequence or damaging the DNA directly.
What is the relationship between DNA sequence and protein structure?
The sequence of bases in DNA determines the sequence of amino acids in a protein, and the specific arrangement of amino acids determines the protein’s final 3D structure and function.
How does the altered protein structure affect its function?
An altered protein structure can result in a protein that is nonfunctional or has reduced activity, which may lead to diseases or disorders.
What is the role of amino acids in protein structure?
Amino acids are the building blocks of proteins, and their sequence determines how the protein folds into its final 3D structure, which is crucial for its function.
Can mutations be beneficial?
Mutations can be beneficial, neutral, or harmful. Beneficial mutations can lead to advantageous traits that improve survival and reproduction, driving evolution.
What is a genetic disorder caused by a mutation?
A genetic disorder is a condition caused by mutations in DNA that lead to abnormal protein function, such as cystic fibrosis or sickle cell anemia.
How does sickle cell anemia illustrate the effect of a mutation on protein function?
In sickle cell anemia, a single point mutation in the hemoglobin gene leads to a change in the amino acid sequence, causing the hemoglobin to form abnormal structures, resulting in misshapen red blood cells.
What is the role of DNA replication in mutations?
During DNA replication, errors in copying the DNA sequence can lead to mutations. If these errors are not repaired, they can be passed on to future generations.
How can mutations lead to cancer?
Mutations in genes that regulate cell growth (oncogenes or tumor suppressor genes) can lead to uncontrolled cell division, resulting in the development of cancer.
What is a mutagen?
A mutagen is an agent or environmental factor that increases the rate of mutation in an organism’s DNA. Examples include chemicals, radiation, and certain viruses.
