Viruses and Biotechnology

Virus

An intracellular obligate parasite that must infect a host cell to reproduce and is not considered alive by most scientists.

Capsid

A protein shell that surrounds and protects the virus and its genetic material.

Envelope

A cell-membrane like structure made of lipids that surrounds the capsid for extra protection.

Spike Protein

Spike-shaped projections made of protein that help viruses attach to and infect their host cells.

Viral Specificity

The specificity of a virus to infect particular types of host cells based on the shape of the virus and its spike proteins.

Eukaryotic Viruses

Viruses that are much more diverse than prokaryotic viruses, with various genome types such as dsDNA, ssDNA, dsRNA, ssRNA.

Retrovirus

A type of virus that stores its genetic material as 3' to 5' single-stranded RNA and requires conversion to DNA for replication.

Antigenic Drift

Mutations in spike antigen proteins that lead to new strains of a virus, such as the flu virus.

Antigenic Shift

A process through which two strains of a virus co-infect a host, potentially leading to new viral genomes.

Lytic Cycle

A viral replication cycle where the virus infects the host cell, replicates, and causes the cell to burst.

Lysogenic Cycle

A viral replication cycle where the viral DNA remains dormant within the host cell, replicating alongside it.

RNA-dependent RNA polymerase

An enzyme used by RNA viruses to replicate their genetic material, usually without proofreading capabilities.

Restriction Enzymes

Proteins that cut DNA at specific sequences, used for gene cloning and DNA analysis.

Polymerase Chain Reaction (PCR)

A technique used to rapidly make millions of copies of a specific DNA sample.

Gel Electrophoresis

A method used to separate DNA, RNA, or proteins based on size and charge.

Bacterial Transformation

A process that enables bacteria to take in non-bacterial DNA and produce proteins from it.

Sanger Sequencing

A method for determining the order of nucleotides in a DNA molecule using chain-terminating nucleotides.

dideoxynucleotide triphosphates (ddNTPs)

Chain-terminating nucleotides used in Sanger sequencing to create varying lengths of DNA strands.

Fluorescently-labeled ddNTPs

Special nucleotides that are used in sequencing to identify base pairs by color during separation.

Reverse Transcriptase

An enzyme coded by retroviruses that synthesizes DNA from an RNA template, violating the central dogma of biology.