Gene Expression

operons

operons

sections of prokaryotic DNA consisting of promoters, genes, and controlling elements

promoter

specific region of a gene where RNA polymerase can bind and begin transcription

plasmids

small circular DNA molecules that replicate separately from the bacterial chromosome. Float in Cytoplasm.

recombinant DNA (rDNA)

DNA that contains genes from more than one source

Why don't bacterial restriction enzymes splice their own DNA?

bacterial add methyl groups to DNA to mask restriction sites

repressors

A protein that suppresses the transcription of a gene.

activator transcription factors

proteins that bind to regulatory and promoter regions so RNA polymerase can bind and start transcription

repressor transcription factors

proteins that bind to regulatory or promoter regions to prevent RNA polymerase from attaching - no transcription occurs

control elements

segments of noncoding DNA in eukaryotic genes that serve as regulatory regions. They can be enhancers or silencers.

differential gene expression

The expression of different sets of genes by cells with the same genome.

histone acetylation

The attachment of acetyl groups to certain amino acids of histone proteins to uncoil DNA so transcription can occur. GENE ON

DNA methylation

The addition of methyl groups to bases of DNA to cause DNA to coil. GENE OFF

How are plasmids used in biotechnology?

Plasmids are used in biotechnology to deliver DNA carrying selective genes.

Why do bacterial transfer plasmids?

plasmids are exchanged during sexual reproduction or uptake of DNA from the environment -- adds additional characteristics. Bacteria evolve!!

What is the evolutionary advantage for humans to have noncoding regions on their DNA?

Genes are further apart which allows genes to be shuffled and recombined.

The DNA in ALL the cells is exactly the same. So how does one cell become a brain cell and another a skin cell?

certain genes are turned off or on in certain cells as cells specialize during development

Operator

a region of the operon where regulatory proteins bind

Prokaryotes

Does NOT contain a nucleus or membrane bound-organelles

Transformation

The uptake and expression of foreign DNA by a bacterial cell though non-viral methods.

Restriction Enzymes

Evolved as a defence mechanism to protect bacteria from invading viruses.

Exon

Molecules with coding regions . Stay inside MRNA.

Intron

Molecules with non-coding regions. Leave the MRNA.

Histones

Eukaryotic DNA is packed into linear Chromosomes coiled around proteins.

Enhancer

Activators attach to enhancers. Gene On.

Silencer

Repressors attaches to silencer. Gene Off.

TF Repressor.

Bind to silencer regulatory regions to block activators or prevent transcription factors from binding to the DNA

TF Activator

Bind to the enhancer regulatory region causing DNA to bend. RNA polymerase to bind to promotes to start transcription.

Lytic Virus

New Viruses assemble and release from the host cells to infect other cells.

Lysogenic Virus

Some viruses that incorporate their DNA into the host chromosomes when released into the host cell.

Lytic Cycle

Attachment stage - Entry - Virus hijacks and takes over host cell. We SEE symptoms.

Lysogenic Cycle

Attachment stage - Entry - Dormant - Virus hijacks and takes over host cell. We SEE symptoms. - Dormant.

Capsid

Protein code that covers the nucleic code of a virus.

Transduction

The process of using a virus to medictate the delivery of DNA fragments or plasmids into a cell, Either Eukaryotes or Prokaryotes.