Gene expression
Is the process in which genetic information stored in genes is used to manufacture functioning proteins
RNA polymerase
The enzyme that creates mRNA in the transcription stage of proteins synthesis
Promoter
The starting sequence of a gene
Coding sequence
The part of a gene that is transcribed
Terminator sequence
The end sequence of a gene what transcription ends
Triplet
Group of three DNA bases
Codon
Group of 3 mRNA bases
Anti-codor
Group of 3 TRNA bases
Ribosomes
Cell organelle that is the site of translation
Point mutation
Mutation that effects a single DNA base
Substitution
A mutation that results in one base being replaced by an other
Substitution (consequences)
If the substitution still codes for the same amino acid = “same sense“ mutations or “silent” mutations
If it changes changes the amino acid ‘missense’ mutation
If it produces a stop codon ‘nonsense’ mutation
Insertion mutation
A mutation where a single DNA base is inserted into the sequence
Insertion (consequence)
This will result in a ‘reading frame shift’ altering all codons down the stream of the mutation
If early in gene then catastrophic for protein
If late in the gene then may slightly alter protein function
Metabolic pathways
A series of linked chemical reactions with an a cell catalysed by enzymes that converts and starting molecule (substrate) into a final product
Mutagens
A physical or chemical agent that alters the DNA structure in an organism leading to permanent changes called mutations
Non-mutagens
A substance that affects gene expression (phenotype) but does not change the DNA basic sequence
