🍕principles of food science review

key term - Codon

Definition

A codon is a sequence of three nucleotides in DNA or RNA that corresponds to a specific amino acid or a stop signal during protein synthesis. Each codon plays a crucial role in translating the genetic code into functional proteins, as they determine the order of amino acids that are linked together to form a protein's structure. The arrangement of these codons is fundamental for accurate protein production and influences the overall function and characteristics of proteins.

5 Must Know Facts For Your Next Test

  1. There are 64 possible codons, but only 20 different amino acids, meaning that some amino acids are encoded by multiple codons.
  2. Codons are read in a non-overlapping manner during translation, meaning each nucleotide is part of only one codon.
  3. The start codon, AUG, not only signals the beginning of protein synthesis but also codes for the amino acid methionine.
  4. Stop codons (UAA, UAG, UGA) signal the termination of protein synthesis, indicating that the polypeptide chain is complete.
  5. Mutations in codons can lead to changes in amino acid sequences, potentially affecting protein structure and function, which can have significant biological consequences.

Review Questions

  • How do codons contribute to the process of translating genetic information into proteins?
    • Codons are essential for translating genetic information into proteins as they provide the instructions for linking amino acids in a specific order. Each set of three nucleotides corresponds to an amino acid or a stop signal during protein synthesis. This precise arrangement ensures that proteins are built correctly, impacting their structure and function in biological systems.
  • Compare and contrast the roles of mRNA and tRNA in relation to codons during protein synthesis.
    • mRNA and tRNA play complementary roles in protein synthesis involving codons. mRNA carries the genetic information from DNA to the ribosome in the form of codons. In contrast, tRNA has anticodons that pair with these mRNA codons, bringing the corresponding amino acids to the ribosome. This coordination between mRNA and tRNA ensures that proteins are synthesized accurately according to the genetic code.
  • Evaluate the impact of mutations in codons on protein function and how this relates to genetic disorders.
    • Mutations in codons can significantly alter protein function by changing the amino acid sequence encoded by the original DNA. Such changes may lead to nonfunctional proteins or proteins with altered properties, which can cause various genetic disorders. For example, a single nucleotide mutation can convert a normal codon into a stop codon, leading to truncated proteins and disrupting cellular processes. Understanding these mutations is crucial for developing targeted therapies for genetic disorders.