molecular genetics!.docx

Gene Expression Regulation

The process that controls the timing and amount of gene expression, allowing cells to specialize in function.

Transcriptional Control

A significant regulatory point that prevents wasteful synthesis of unnecessary RNA and proteins in cells.

Transcriptional Regulators

Specialized proteins that control gene expression in response to environmental signals.

Activators

Proteins that enhance the transcription of specific genes by binding to DNA.

Repressors

Proteins that block or decrease gene transcription by binding to operator sites.

Consensus Sequence

Common patterns in DNA sequences recognized by transcriptional regulators.

RNA Polymerase

The enzyme responsible for synthesizing RNA from a DNA template.

Lac Operon

A set of genes in E. coli that regulate lactose metabolism, controlled by the lac repressor and CAP.

Trp Operon

A set of genes involved in tryptophan synthesis in bacteria, regulated by attenuation.

Enhancers

Regulatory DNA sequences that enhance gene expression by binding transcription factors.

Silencers

DNA sequences that decrease gene expression by binding repressors.

PCR (Polymerase Chain Reaction)

A technique used to amplify specific DNA fragments through repeated cycles of denaturation, annealing, and extension.

Template DNA

The DNA sample that contains the region to be amplified in PCR.

Taq DNA Polymerase

A heat-stable enzyme used in PCR to synthesize new DNA strands.

Primers

Short sequences of nucleotides that initiate DNA synthesis during PCR.

dNTPs

Deoxynucleotide triphosphates; the building blocks for new DNA synthesis.

Electrophoresis

A technique used to separate DNA or RNA molecules based on size using an electric field.

Southern Blot

A method to detect specific DNA sequences within a DNA sample by hybridization with a labeled probe.

Northern Blot

A technique to study RNA molecules by detecting specific RNA sequences through gel electrophoresis.

Western Blot

A technique used to detect specific proteins in a sample using antibodies.

DNA Microarray

A high-throughput method used to measure the expression levels of thousands of genes simultaneously.

qPCR (Quantitative PCR)

A technique used to quantify DNA or RNA in real-time during the amplification process.

Plasmids

Small, circular DNA molecules independent of chromosomal DNA, often used as vectors in genetic engineering.

Recombinant DNA Technology

Techniques for combining DNA from different sources to create new genetic combinations.

Restriction Enzymes

Proteins that cut DNA at specific sequences, crucial for cloning and recombinant DNA technology.

Transposons

Mobile genetic elements that can move within a genome, causing mutations and genetic diversity.

CRISPR-Cas9

A revolutionary technology used for precise genome editing based on bacterial immune systems.

Translational Control

Regulation of gene expression at the translation level, affecting how proteins are synthesized.

Riboswitches

Regulatory RNA elements that change their structure in response to metabolite binding.

Codon Degeneracy

The phenomenon where multiple codons can specify the same amino acid.

Frameshift Mutation

A mutation caused by insertion or deletion of nucleotides that alters the reading frame of the gene.