Molecular Biology, Virology, and Genetics Lecture Review

Vocabulary practice flashcards covering diagnostic techniques, immunology, viral genetics, prions, DNA replication, transcription, translation, and operon regulation from the lecture transcript.

CCR five delta thirty two mutation

A specific genetic mutation in the human bloodline associated with HIV resistance.

RT PCR

A technique used for viruses with an RNA genome that utilizes reverse transcriptase to generate cDNA before amplifying DNA fragments of known sizes.

Reverse transcriptase

An enzyme associated with HIV that uses an RNA template to synthesize complementary DNA (cDNA).

Tacholimarase

The highly accurate enzyme responsible for performing the PCR amplification portion of DNA fragments.

ELISA

A rapid diagnostic test performed in a 96-well plate that yields results in under an hour with an accuracy of approximately $75\%$ to $85\%$ by using enzyme-linked antibodies.

Variable region

The specific region of an antibody that binds uniquely to a particular antigen or pathogen surface feature, such as Gp120.

Fc region

The constant region of an antibody, which exists in five distinct classes: IgA, IgD, IgE, IgG, and IgM.

Secondary antibody

A laboratory-engineered antibody covalently linked to an enzyme whose variable region binds directly to the constant (Fc) region of a primary antibody in an ELISA.

Antigenic drift

A slow evolutionary process where a virus gradually accumulates spontaneous mutations over time, altering glycoprotein spike shapes to avoid antibody binding.

Antigenic shift

A rapid evolutionary process occurring when two different viral strains simultaneously infect the same host cell, reassorting their segmented genomes to produce a brand new strain.

Segmented genome

A viral genome that is naturally divided into multiple distinct RNA or DNA pieces rather than being arranged as a single continuous nucleic acid molecule.

Prion

An infectious, non-living small protein that lacks a nucleic acid genome and causes normal proteins to misfold from alpha helices into beta pleated sheets.

Creutzfeldt Jakob disease

A fatal human neurodegenerative disease caused by misfolded prion proteins that lead to neuronal apoptosis, macrophage cleanup, and large voids or holes in brain tissue.

Scrapie

A prion disease that infects sheep herds, historically eradicated on affected farms by completely slaughtering and incinerating the animals.

Chronic wasting disease

A prion disease found in deer populations that spreads more rapidly as deer densities increase.

Topoisomerase inhibitors

Chemotherapeutic drugs that block topoisomerase function in growing cancer cells, causing supercoils to accumulate and break DNA during replication.

Gyrase

A bacterial enzyme that cuts phosphodiester bonds to relieve supercoils and ligates the double helix back together during DNA replication.

SSBPs

Single-strand binding proteins that prevent hydrogen bonds from reforming between separated parental DNA strands during replication.

Primase

An enzyme that synthesizes an RNA primer on the DNA strand to provide a free $3'$ hydroxyl group necessary for DNA polymerases to start synthesis.

DNA polymerase three

The primary replication enzyme that synthesizes daughter strand DNA by adding nucleotides to the free $3'$ hydroxyl end of an existing primer.

DNA polymerase one

The enzyme that degrades the RNA primer by breaking phosphodiester bonds and replaces the ribonucleotides with deoxyribonucleotides.

DNA ligase

An enzyme that seals gaps in the sugar-phosphate backbone by forming phosphodiester bonds between adjacent DNA segments.

Okazaki fragment

A short fragment of newly synthesized DNA formed on the lagging strand during DNA replication.

Promoter

A specific sequence of DNA where RNA polymerase binds before scanning for the transcription initiation site.

+1 site

The specific nucleotide position on the DNA strand where transcription by RNA polymerase is initiated.

Release factor

A factor that recognizes a stop codon and triggers termination of translation because there is no attached amino acid to form a peptide bond.

Silent mutation

A mutation that changes a codon sequence in the mRNA to a different codon that still specifies the exact same amino acid.

Operator

A regulatory DNA sequence within an operon where a repressor protein binds to physically block transcription by RNA polymerase.

CAP-cAMP complex

A regulatory protein complex formed when cyclic AMP levels rise under low glucose conditions, functioning to tether RNA polymerase onto the weak promoter of the lac operon.