Question
SYNTHESIS: Answer each of the following using complete sentences.
1. What is the relationship between DNA, codons, and proteins?
2. How does the shape of a protein relate to its function? Refer to specific
details about this case and sickle cell anemia.
3. Construct an explanation based on evidence for how the structure of DNA determines the
structure of proteins which carry out the essential functions of life through systems of specialized
cells. (HS-LS-1)
Answer
1. DNA contains the genetic information that codes for the sequence of amino acids in proteins. Codons are sequences of three nucleotides in DNA that correspond to specific amino acids. Proteins are made up of chains of amino acids that are determined by the sequence of codons in DNA.
2. The shape of a protein is crucial to its function because it determines how the protein interacts with other molecules in the body. In the case of sickle cell anemia, a single amino acid substitution in the protein hemoglobin causes it to form abnormal shapes, leading to the characteristic sickle-shaped red blood cells and impaired oxygen transport.
3. The structure of DNA determines the sequence of amino acids in proteins through the process of transcription and translation. During transcription, the DNA sequence is copied into a messenger RNA (mRNA) molecule, which carries the genetic information to the ribosome. The ribosome reads the mRNA sequence and uses it to assemble a chain of amino acids in the correct order to form a protein. The specific sequence of amino acids determines the protein's structure and function, which in turn allows it to carry out essential functions in specialized cells and systems in the body.