Cell and Molecular Biology Lecture Flashcards

Vocabulary practice flashcards covering cell biology history, microscopy, prokaryotes and eukaryotes, extreme archaea, cell differentiation, and virology.

Robert Hooke (1665)

An English microscopist and curator of the Royal Society of London who used a 2-lens microscope with $20-50\times$ magnification to observe empty cell walls of dead cork tissue, coining the term "cells" based on a monastic chamber metaphor.

Antonie van Leeuwenhoek

A Dutch maker of single-lens simple microscopes with $275\times$ magnification who first observed "animalcules" in pond water, bacteria in pepper-soaked water, and teeth scrapings.

Cell Theory

The foundational biological theory formulated by Schleiden, Schwann, and Virchow stating that all organisms consist of one or more cells, the cell is the structural unit of life, and cells arise only by division from a preexisting cell.

Matthias Schleiden (1838)

A German lawyer and botanist who concluded that all plants are composed of cells and that plant embryos arise from a single cell.

Theodor Schwann (1839)

A German zoologist who determined that plant and animal cells are fundamentally similar structural units.

Rudolf Virchow (1855)

A German pathologist who proposed the principle of biogenesis, establishing that cells can arise only by division from a preexisting cell.

An electron microscope designed to scan the surface of a specimen with a focused beam of electrons.

Scanning Electron Microscope (SEM)

Transmission Electron Microscope (TEM)

An electron microscope used to view internal cellular structures in thin specimens through which electrons can pass.

Field Emission Scanning EM (FESEM)

An electron microscope using a Field Emission Gun (FEG) and an applied potential gradient to provide topographical elemental information at $10\times$ to $300{,}000\times$ magnification with unlimited depth.

HeLa Cells (1951)

The first cultured human cells, isolated from Henrietta Lacks by George and Margaret Finney Gey at John Hopkins Univ.

Prokaryotes

Simpler organisms lacking a true nucleus, possessing a nucleoid, reproducing nonsexually without a mitotic spindle, and containing a single circular chromosome.

Eukaryotes

Complex organisms including protists, fungi, plants, and animals characterized by a true membrane-bound nucleus, chromatin, and internal membrane organelles.

Methanogens

Prokaryotic archaea capable of converting $CO_2$ and $H_2$ gases into methane ($CH_4$).

Halophiles

Prokaryotic archaea that thrive in extremely salty environments.

Acidophiles

Prokaryotic archaea that thrive in extremely acidic environments at a pH as low as $0$.

Strain 121

A hyperthermophilic archaeon capable of growing and dividing in superheated water at temperatures of $121\text{ }^\text{o}\text{C}$.

Intron

A non-coding sequence of genetic material present in eukaryotic cells.

Exon

A coding sequence of genetic material present in host mRNA and eukaryotic genes.

Cell Differentiation

The developmental process through which specialized cell types acquire a distinctive appearance and unique molecular material.

Louis Pasteur (1862)

A scientist who discovered disease- and fermentation-causing microbes, developed pasteurization, and pioneered rabies and anthrax vaccines.

Dmitri Ivanovsky (1892)

A Russian biologist who first discovered viruses through his research on tobacco mosaic disease.

Wendell Stanley (1935)

A scientist who demonstrated that the virus causing tobacco mosaic disease could be crystallized while retaining its infectivity.

Virion

A macromolecular virus particle in its extracellular state outside of a living host cell.

Bacteriophages

Viruses that infect bacteria, consisting of a polyhedral head containing DNA and a tail structural assembly.

First Eukaryotic Common Ancestor (FECA)

The ancestral evolutionary lineage of prokaryotes that first developed internal membrane compartments.

Last Eukaryotic Common Ancestor (LECA)

The common ancestor of all existing eukaryotic lineages, possessing mitochondria, cilia, intron splicing mechanisms, and meiosis.

Human Immunodeficiency Virus (HIV)

An RNA retrovirus encased in a protein capsid and host-derived lipid bilayer that attacks CD4+ T cells, leading to severe immune system deficiency.

Reverse Transcriptase

A viral retrotranscription enzyme in HIV that synthesizes cDNA from a single-stranded viral RNA template.

Integrase

A viral enzyme that inserts viral cDNA produced by reverse transcriptase directly into the host cell genome.

Severe Acute Respiratory Syndrome Coronavirus

A crown-spiked RNA virus family member responsible for COVID-19, first detected in Wuhan, China in 2019.

Ebola Virus

A filamentous RNA virus in the family Filoviridae encoding $19{,}000$ nucleotides, hosted by fruit bats (Pteropodidae), first discovered in 1974 near the Ebola River in Congo.