Microbes Shaping History - Vocabulary

Vocabulary flashcards covering historical microbes, pathogens, evolutionary impacts, key diseases, and microbiological breakthroughs based on Unit 1 Lecture 3.

Cyanobacteria

A prokaryotic organism in Domain Bacteria (unicellular or filamentous phototroph) that performs oxygenic photosynthesis using $H_2O$ as an electron donor to generate $O_2$ as a waste product, triggering the Great Oxidation Event (GOE) between $2.4$ and $2.8\text{ billion years ago}$.

Anoxygenic Photosynthesis

A form of photosynthesis carried out by early phototrophs (such as purple and green bacteria) that uses $H_2$, $Fe^{2+}$, or $H_2S$ as electron donors without generating $O_2$ as a waste product.

Oxygenic Photosynthesis

A form of photosynthesis carried out by cyanobacteria that utilizes $H_2O$ as an electron donor and produces $O_2$ as a waste product.

Phototroph

An organism that utilizes light energy to carry out metabolic and cellular processes.

Great Oxidation Event (GOE)

A major evolutionary transition occurring $2.4\text{ to }2.8\text{ billion years ago}$ triggered by cyanobacteria, which dramatically raised atmospheric oxygen levels and enabled the development of multicellular life.

Zoonotic Disease

An infectious disease caused by a pathogen that spills over from animals to humans, historically accelerated by animal domestication.

Yersinia pestis

A prokaryotic bacterium in Domain Bacteria (Phylum Proteobacteria) that serves as the etiologic agent of bubonic plague, transmitted via flea or animal bites and respiratory droplets.

Bubo

A swollen, inflamed, and painful lymph node characteristic of bubonic plague infection.

Phytophthora infestans

A eukaryotic protist and fungus-like water mold in Domain Eukarya that causes late potato blight, which destroyed Irish potato crops between $1845$ and $1860$ and precipitated the Irish Potato Famine.

Human Immunodeficiency Virus (HIV)

A nonliving, obligate intracellular RNA retrovirus that targets and destroys human T cells, compromising the immune system and leading to AIDS.

Retrovirus

An RNA virus (such as HIV) that replicates by transcribing its RNA genome into proviral DNA inside a host cell.

Acute HIV Infection

The early phase of HIV infection characterized by flu-like symptoms and a high viral load in the blood.

Latent Period (HIV)

The clinically asymptomatic phase of HIV infection during which proviral DNA remains quiescent inside host cells, leading to a low viral load.

Acquired Immunodeficiency Syndrome (AIDS)

The advanced stage of untreated HIV infection defined by a severe reduction in T helper cell count, high viral load, and high vulnerability to opportunistic infections.

PrEP (Pre-Exposure Prophylaxis)

A prophylactic medication regimen taken prior to potential HIV exposure to prevent infection in high-risk individuals.

PEP (Post-Exposure Prophylaxis)

A short-term antiretroviral medication course taken immediately following a potential HIV exposure to prevent viral establishment.

Mycobacterium tuberculosis

A prokaryotic bacterium in Domain Bacteria (Phylum Actinobacteria) that is the etiologic agent of tuberculosis (TB), causing lung granulomas, wasting, chest pain, and coughing up blood.

MDR/RR-TB

Multidrug- or rifampicin-resistant tuberculosis, a form of $M.\text{ tuberculosis}$ that resists standard front-line anti-TB medications, creating a global public health threat.

Influenza Virus Type A

A nonliving, obligate intracellular RNA virus containing $8\text{ linear segments}$ that causes severe seasonal flu, epidemics, and global pandemics in humans and animals.

Hemagglutinin (H Spike)

A surface glycoprotein spike on the influenza virus required for attachment and entry into host cells.

Neuraminidase (N Spike)

A surface enzyme spike on the influenza virus necessary for releasing newly synthesized viral particles from host cells.

Antigenic Drift

A process involving small, gradual genetic mutations in the hemagglutinin (H) and neuraminidase (N) genes of influenza viruses over time.

Antigenic Shift

An abrupt, major genetic reassortment in type A influenza viruses that produces new H and/or N protein combinations capable of causing worldwide pandemics.

Penicillium rubens

A eukaryotic mold fungus in Domain Eukarya (Phylum Ascomycota) discovered by Sir Alexander Fleming in $1928$ to produce penicillin, the first therapeutic antibiotic isolated from a microbial source.

Antibiotic

A chemical substance produced naturally by microorganisms or manufactured synthetically that inhibits or destroys bacteria.

Thermus aquaticus

A prokaryotic extremophilic bacterium in Domain Bacteria that thrives at temperatures between $75$ and $80^{\text{o}}\text{C}$ and provides heat-stable Taq polymerase for PCR.

Extremophile

An organism adapted to survive and thrive under extreme environmental conditions, such as high temperatures or extreme pH.

Polymerase Chain Reaction (PCR)

A molecular technique conceived by Kary Mullis in $1983$ that uses Taq polymerase to rapidly replicate and amplify specific targeted DNA sequences.

Etiologic Agent

The specific pathogen, microorganism, or biological agent responsible for causing a particular disease.

Quarantine

A public health measure enforcing the isolation of infected or potentially exposed individuals for a defined period (historically $40\text{ days}$) to contain contagion.