Introduction to Microbes and Their Building Blocks

Flashcards covering key terms and definitions from Chapter 01: Introduction to Microbes and Their Building Blocks.

Microbiology

A specialized area of biology that deals with living things ordinarily too small to be seen without magnification.

Pathogens

Microbes that cause disease, with over $2000$ different types causing billions of infections worldwide each year.

Eukaryotes

Organisms possessing cells with a true nucleus and membrane-bound organelles such as mitochondria and chloroplasts.

Bacteria

Single-celled prokaryotic microorganisms that lack a true nucleus and membrane-bound organelles.

Archaea

Single-celled prokaryotic microorganisms lacking a true nucleus that are evolutionary distinct from bacteria.

Prokaryotes

Organisms encompassing bacteria and archaea whose cells lack a true nucleus.

Akaryotes

An alternate term used for prokaryotes, meaning "no nucleus".

Anoxygenic Photosynthesis

Light-fueled conversion of carbon dioxide to organic material that occurred in bacteria before plants evolved and did not produce oxygen.

Oxygenic Photosynthesis

A light-fueled process that evolved from anoxygenic photosynthesis, produces oxygen, and is carried out by microorganisms responsible for $70\%$ of the earth's photosynthesis.

Biotechnology

The manipulation of microorganisms, plants, and animals for the purpose of creating new products and genetically modified organisms (GMOs).

Recombinant DNA Technology

A technique that makes it possible to transfer genetic material from one organism to another and deliberately alter DNA.

Bioremediation

The use of microbes already present or introduced intentionally to restore stability or clean up toxic pollutants.

Organelles

Small, double-membrane-bound structures in eukaryotic cells that perform specific cellular functions.

Viruses

Acellular, non-independently living infectious agents composed of hereditary material (DNA or RNA) surrounded by a protein coat and sometimes a membrane.

Prions

Infectious protein particles that contain no nucleic acid and act like infectious microorganisms.

Spontaneous Generation

The belief that invisible vital forces present in matter led to the creation of life from nonliving matter (abiogenesis).

Biogenesis

The principle that living things arise only from others of the same kind.

Robert Hooke

Scientist who studied household objects and plants, describing cellular structures and drawing sketches of "little structures" that appeared alive.

Antonie van Leeuwenhoek

Dutch merchant who manufactured simple microscopes magnifying up to $300\times$ and observed "animacules" in water and tooth scrapings.

Joseph Lister

Surgeon who introduced aseptic techniques in surgery, greatly reducing post-surgical infections.

Louis Pasteur

French scientist who disproved spontaneous generation, invented pasteurization, and conducted early studies linking human disease to infection.

Robert Koch

Scientist who established postulates to determine microbial etiology of disease and proved in 1875 that anthrax was caused by Bacillus anthracis.

Pasteur's Swan-Neck Flask Experiment

An experiment demonstrating that broth in swan-necked flasks remained sterile when intact, but grew microbes when exposed to airborne dust, disproving spontaneous generation.

Polymerase Chain Reaction (PCR)

A breakthrough technique developed in the 1980s that detects tiny amounts of DNA and amplifies them into quantities sufficient for analysis.

Small RNAs

Short RNA molecules that do not code for protein but play critical roles in regulating gene expression and cell function.

Human Microbiome Project (HMP)

An initiative that revealed that while specific microbial species vary across individuals, overall bacterial metabolic capabilities are remarkably similar among humans.

CRISPR Technology

A naturally occurring bacterial and archaeal system adapted in 2013 for precise gene editing in any organism.

Macromolecules

Very large biological superstructures consisting of four main classes: carbohydrates, lipids, proteins, and nucleic acids.

Monomers

The small molecular subunits that serve as the basic building blocks of polymers.

Polymers

Large molecules formed by linking repeating chains of monomer subunits.

Monosaccharides

Simple sugars consisting of 3 to 7 carbon atoms, such as glucose and fructose, that serve as building blocks for disaccharides and polysaccharides.

Disaccharides

Carbohydrates formed by linking two monosaccharides, such as maltose, lactose, and sucrose.

Polysaccharides

Long chains of monosaccharides that function in structural support and energy storage, such as cellulose, starch, chitin, and peptidoglycan.

Peptidoglycan

A structural polysaccharide component of the bacterial cell wall.

Lipopolysaccharide

A lipid-carbohydrate complex found in the outer membrane of gram-negative bacterial cell walls.

Glycocalyx

A protective outer layer on cell surfaces that functions in cellular attachment and adhesion.

Triglycerides

Concentrated storage lipids composed of a glycerol molecule bound to three fatty acids that yield twice as much energy per gram as carbohydrates.

Phospholipids

Membrane lipids containing a charged hydrophilic phosphate head and uncharged hydrophobic fatty acid tails that form cell membrane bilayers.

Steroids

Complex ringed lipid structures found in cell membranes and hormones, such as cholesterol and ergosterol.

Waxes

Esters formed between a long-chain alcohol and a saturated fatty acid, providing waterproofing and present in the cell walls of Mycobacterium tuberculosis and Mycobacterium leprae.

Proteins

Predominant organic cellular molecules formed by chains of 20 different amino acids linked together by peptide bonds.

Primary Structure

The specific type, number, and sequential order of amino acids in a polypeptide chain.

Secondary Structure

Protein folding formed by hydrogen bonds between functional groups, producing structural patterns such as the alpha helix and beta pleated sheet.

Tertiary Structure

The overall 3D folding of a polypeptide chain stabilized by covalent disulfide bonds between cysteine residues and other R-group interactions.

Quaternary Structure

The complex protein structure formed when two or more individual polypeptide chains combine into a multiunit assembly.

Native State

The functional, correctly folded three-dimensional shape of a protein under natural physiological conditions.

Denaturation

The disruption of a protein's native three-dimensional structure caused by heat, acid, alcohol, or chemical disinfectants.

Enzymes

Protein catalysts that accelerate chemical reactions in cells without being consumed in the process.

Antibodies

Glycoproteins produced by the immune system that specifically recognize and attach to microorganisms and foreign targets.

Deoxyribonucleic Acid (DNA)

A double-stranded nucleic acid containing deoxyribose sugar and thymine that carries coded genetic instructions for heredity.

Ribonucleic Acid (RNA)

A single-stranded nucleic acid containing ribose sugar and uracil that carries out DNA instructions to facilitate protein synthesis.

Adenosine Triphosphate (ATP)

A nucleotide energy molecule consisting of adenine, ribose, and three high-energy phosphate groups that releases energy when phosphate bonds are broken.

Taxonomy

The science of classifying, naming, and identifying living organisms, formalised by Carl Von Linné.

Nomenclature

The system of assigning formal scientific names to taxonomic categories and individual organisms.

Binomial System of Nomenclature

A naming system that combines an italicized Genus name and species name to uniquely identify organisms.

Taxonomic Ranks

The descending hierarchy of biological classification: Domain, Kingdom, Phylum (or Division), Class, Order, Family, Genus, Species.

Phylogeny

The taxonomic scheme representing the natural evolutionary relatedness between groups of living organisms.

Woese-Fox System of Taxonomy

A domain-based classification system (Bacteria, Archaea, Eukarya) proposed in 1975 based on conserved small subunit ribosomal RNA (ssu rRNA) sequences.