Fluorophores and Transposons Lecture Summary

Flashcards covering key vocabulary from the lecture on fluorophores, transposons, and associated biological concepts.

Fluorophores

Substances that absorb light of short wavelength and emit light of longer wavelength.

Excitation-Emission Cycle

Process by which fluorophores undergo multiple cycles of absorbing and emitting light before being chemically modified.

Bleaching

Process in which fluorophores stop producing fluorescence due to chemical modification.

Transposons

Segments of DNA that move within the genome via 'cut-and-paste' mechanisms.

Transposase

Enzyme that cuts transposons and facilitates their integration into target DNA.

LTR Retrotransposons

Transposons similar to retroviruses, lacking envelope proteins, that generate mRNA and replicate via reverse transcription.

Reverse Transcriptase

Enzyme encoded by retrotransposons that synthesizes DNA from an RNA template.

Integrase

Enzyme that mediates the insertion of DNA into the genome, similar to transposases.

LINEs

Long interspersed elements that contain two protein-coding genes, ORF1 and ORF2.

ORF1

Protein coding gene in LINEs that produces ORF1p, which binds nucleic acids.

ORF2

Protein coding gene in LINEs that encodes a reverse transcriptase and nuclease.

SINEs

Short interspersed elements, non-coding sequences that rely on LINEs for mobility.

G-Proteins

Proteins that exist in 'on' (GTP bound) or 'off' (GDP bound) conformations.

GEFs (Guanine Exchange Factors)

Proteins that switch G-proteins from 'off' to 'on' state.

GAPs (GTPase Activating Proteins)

Proteins that switch G-proteins from 'on' to 'off' state.

Calmodulin

Protein that binds calcium ions, undergoing conformational changes to regulate other proteins.

Gene

Entire nucleic acid sequence necessary for synthesizing a functional product, such as a polypeptide.

Exons

Coding segments of a gene that are transcribed into mRNA.

Introns

Non-coding segments of a gene that are transcribed but removed during mRNA processing.

Control Regions

Regulatory elements including promoters and cis regulatory factors that are not transcribed.

Promoter

Region of DNA that initiates transcription of a particular gene.

Distinction between DNA Transposons and Retrotransposons movement

DNA transposons move via a 'cut-and-paste' mechanism, directly excising and inserting DNA, whereas retrotransposons utilize a 'copy-and-paste' mechanism involving an RNA intermediate and reverse transcription.

Autonomy comparison of LINEs and SINEs

LINEs are autonomous retrotransposons, encoding the enzymes necessary for their own movement (like reverse transcriptase). SINEs are non-autonomous and depend on the enzymatic machinery provided by LINEs for their transposition.

Similarities and differences: LTR Retrotransposons and Retroviruses

Both LTR retrotransposons and retroviruses use reverse transcription and have LTRs. However, LTR retrotransposons lack genes for envelope proteins, preventing them from forming infectious viral particles, unlike retroviruses.