8.4 Flashcards
Codon
A group of 3 bases that code for a specific amino acid
Antiocodon
A group of 3 bases that pair with a codon, following base rules.
Translation
The process by which the message from an mRNA strand is translated and turned into a protein.
Start codon
The codon that signals the start of the translation process for the strand. Any codons before this one are nullified and do not go through the process. Start codon codes for Met and will be AUG.
Stop codon
The codon that signals the end of the translation process for the strand. Any codons after this are nullified and do not go through the process. Can be a few different codons.
Positive transcription factor.
Binds to DNA and “activates” it, letting it go through the transcription process.
Negative transcription factor.
Binds to DNA and “deactivates” it, stopping it from going through the transcription process
Affinity
The strength of attraction between two substances
Mutation
A change in the base sequence in a molecule of DNA.
mRNA
Provides the message for the amino acid sequence
tRNA
Transfers the amino acids. Also contains anticodons that pair with mRNA codons to put the amino acids in the correct order.
rRNA
Facilitates the matching of tRNA and mRNA. Also joins amino acids together in order to synthesize proteins
Point mutation
The substitution of a single base. 3 types:
Silent/synonymous: When the mutation doesn’t change an amino acid in the sequence.
Missense: When the new base results in the coding of a different amino acid
Nonsense: When the new base causes its codon to become a “Stop” codon.
Frameshift mutation
Shift in the reading frame. Two types:
Insertion: When a certain number of bases are added into the sequence
Deletion: When a certain number of bases are removed from the sequence
Translate this sequence:
AUGCCACAUGGAUCCUAG
Met, Pro, His, Gly, Ser, Stop
How is protein production affected by affinity and both negative and positive transcription factors?
More affinity = More production
More positive transcription factors = More production
More negative transcription factors = Less production
