1140 Unit 4 Lecture Mutations Operons FALL24

Mutation

Any permanent change in the DNA sequence.

Point Mutation

A mutation that involves a single nucleotide change.

Mutagenesis

The production of mutations.

Mutagens

Physical or chemical agents that can cause mutations.

Spontaneous Mutations

Mutations that occur due to errors in natural biological processes.

Induced Mutations

Mutations that result from environmental influences.

Silent Mutation

A mutation that does not change the amino acid produced.

Missense Mutation

A mutation that changes one amino acid to another, one base different

Nonsense Mutation

A mutation that results in a premature stop codon, leading to a shortened protein.

Insertion-Reading Frame Mutation

A mutation Insertion of one base, throws off all codons downstream by shifting bases to the right by one space

Deletion-Reading Frame Mutation

A mutation where bases are deleted, throws off all codons downstream by shifting bases to the left by one spac

Gene Expression

The process of turning a gene into a product, typically a protein.

DNA—RNA—>Protein

Gene Regulation

The control of when and how genes are expressed, makes proteins only when you need them

Operon

A control region that includes a promoter and operator, regulating gene expression in prokaryotes.

Repressor

A regulatory protein that binds to the operator and blocks transcription.

Structural Genes

Genes that code for the actual proteins needed by the cell

Lac Operon

Genes for metabolizing lactose sugar found as ‘food’ in its environment,Works through Repressor molecules

Beta-galactosidase LacZ

An enzyme that hydrolyzes lactose into glucose and galactose.

Permease LacY

A transport protein that facilitates lactose entry into the cell.

Transacetylase LacA

An enzyme that adds an acetyl group from acetyl CoA in metabolic pathways.

Growth Factors

Chemical signals that instruct cells to grow and divide.

Promoter

site where RNA polymerase attaches to start transcription

Operator site

siite acting as “switch” between promoter & structural genes