DNA and Genomes Overview

A gene system where transcription is turned ON by the presence of a substrate.

A gene system where transcription is turned OFF by the presence of a product.

A negative inducible operon in E. coli that allows the cell to metabolize lactose.

The lac operon is regulated by a repressor protein (LacI) and the presence of lactose; when lactose is present, the repressor detaches from the operator, allowing transcription.

A regulatory mechanism where bacteria prioritize using glucose over other sugars when glucose is available.

lacZ (beta-galactosidase), lacY (permease), and lacA (galactosidase acetyltransferase) participate in lactose digestion.

The process of controlling how genes are expressed within prokaryotes.

Proteins that bind to specific DNA sequences to control the initiation of transcription.

The phase of transcription where RNA polymerase extends the RNA transcript, starting from the initiation site.

A protein that helps RNA polymerase bind to the promoter region of DNA, initiating transcription.

A mechanism that stops transcription when an RNA sequence with a hairpin loop and a GC-rich region is formed.

A mechanism that involves the Rho protein, which binds to the RNA transcript and pulls it away from RNA polymerase.

The initial RNA molecule produced after transcription, before any processing.

The processed RNA molecule ready for translation, containing a 5' cap, poly-A tail, and introns removed.

A process where different combinations of exons from a single gene can be spliced together, creating multiple protein isoforms.

The set of rules that translates nucleotide sequences in mRNA into amino acid sequences in proteins.

The process of DNA replication in prokaryotes involves a single origin of replication (OriC) where the DNA double helix is unwound, and the process occurs simultaneously on both strands, creating two identical DNA molecules.

A complex of proteins involved in DNA replication in prokaryotes. It includes DNA polymerase, helicase, and other enzymes.

Prokaryotes have a smaller, simpler replisome with fewer proteins, while eukaryotes have a larger, more complex replisome with additional proteins and machinery. Prokaryotes have one replisome, while eukaryotes have multiple replisomes.

A segment of DNA that encodes a functional RNA molecule, such as mRNA, tRNA, or rRNA.

A prokaryotic gene typically consists of a promoter region, a coding region (ORF), and a terminator region. The promoter contains the -35 and -10 boxes for the binding of RNA polymerase.

A eukaryotic gene is more complex, with a distal promoter, proximal promoter, core promoter, exons, introns, and a polyadenylation signal.

RNA polymerase binds to the promoter region of a gene, unwinds the DNA double helix, and initiates the synthesis of RNA.

RNA polymerase moves along the DNA template strand, adding nucleotides to the growing RNA molecule. Transcription terminates when RNA polymerase reaches a specific terminator sequence.