Chapter 8 Lesson 4 Flashcards
What is the definition of a codon?
A combination of three letters of mRNA to code for one amino acid
What is the definition of an anticodon?
A sequence of three nucleotides in transfer RNA that binds to a corresponding codon and designates a specific amino acid
What is the definition of translation?
Three bases that get assigned to a specific codon
What is the definition of a start codon?
A codon that tells the amino acid to begin working, typically the base pairs AUG
What is the definition of a stop codon?
A codon that tells the amino acid to stop working, typically has the base pairs UAA, UAG, or UGA
What is the definition of a positive transcription factor?
A protein that binds to DNA at specific sites and actively enhances the rate of transcription of a gene
What is the definition of a negative transcription factor?
A protein that binds to DNA and inhibits the process of transcription
What is the definition of affinity?
The strength of attraction or binding between two molecules
What is the definition of a mutation?
Changing of the base sequence of a gene
What is the role of tRNA in translation?
Transferes amino acids, contains anticodons that pair with mRNA codons to put amino acids in the correct order
What is the role of mRNA in translation?
Contains the message/code for the amino acid sequence
What is the role of rRNA in translation?
Facilitate matching of mRNA codons and tRNA anticodons and join amino acids to synthesize proteins
What are the two types of mutations?
1) Point
2) Frameshift
What are the three types of point mutations?
- Silent/Synonymous
- Missense
- Nonsense
What are the two types of frameshift mutations?
- Insertions
- Deletions
What are silent mutations?
Substitutions in a single base and does not change the amino acids
What are missense mutations?
Substitutions in a single base and changes the amino acids
What are nonsense mutations?
Substitutions in a single base and stops the amino acid sequence prematurely
What are insertion mutations?
Mutations which insert or add codons/amino acids from the polypeptide chain
What are deletion mutations?
Mutations which delete or remove codons/amino acids from the polypeptide chain
What three things are mutations caused by?
1) DNA Replication
2) Mutagens
3) Viral Infections
When do mutations not have major consequences?
1) When they are fixed by repair mechanisms
2) When they occur in body cells which do not replicate
