8.4 Study Guide Flashcards
(18 cards)
Definition of Codon
A sequence of three nucleotides in DNA or RNA that codes for a specific amino acid.
Definition of Anticodon
A sequence of three nucleotides in DNA or RNA that is complementary to a specific codon
Definition of Translation
The process of translating the sequence of a mRNA molecule to a sequence of amino acids during protein synthesis
Start Codons
AUG and methionine
Stop Codons
UGA, UAA, UAG
Definition of Positive Transcription Factor
A protein that binds to DNA and enhances the transcription of a gene
Definition of Negative Transcription Factor
A protein that binds to specific DNA sequences and inhibits the transcription of a gene.
Definition of Affinity
The strength of attraction between two substances.
Definition of Mutation
Change in the base sequence in a molecule of DNA
Role of mRNA
Contains message/code for amino acid sequence
Role of tRNA
Transfers amino acids, contains anticodons that pair with mRNA codons to put a.a. in the correct order
Role of rRNA
Facilitates matching of mRNA and tRNA and joins amino acids to synthesize protein.
What is point mutation?
Substitution of single base
What does point mutation result in?
Silent mutation, Missense mutation, and Nonsense mutation.
Silent mutation
Same protein produced
Missense mutation
One different protein produced
Nonsense mutation
Produces a stop
What is frameshift mutation?
Insertions, deletions, and shifts in the reading frame
