microbiology

• Microorganisms include: Bacteria, Archaea, Protozoa, Fungi, Helminths, Algae, Viruses, Prions
• Microbes are very easy and very difficult to study
• Bacteria and archaea are predominantly single-celled, while eukaryotes can be single-celled or highly complex multicellular organisms
• Microbes are ubiquitous and found deep in the earth’s crust, in polar ice caps and oceans, inside the bodies of plants and animals, and in the earth’s landscape
• Microorganisms are the main forces that drive the structure and content of the soil, water, and atmosphere
• Historical uses of microbes by humans include bread, alcohol, and cheese production, treatment of wounds, mining precious metals, and cleaning up contamination
• Genetic engineering manipulates the genetics of microbes, plants, and animals to create new products and GMOs
• The vast majority of microorganisms that associate with humans are harmless or beneficial, but pathogens can cause disease
• Emerging and reemerging diseases include AIDS, Hepatitis C, Zika virus, West Nile virus, and Tuberculosis
• Increasing number of patients with weakened defenses are subject to infections by common microbes and an increase in drug-resistant microbes
• Eukaryotes contain organelles and are larger than bacteria and archaea, which lack organelles
• Viruses are not independently living cellular organisms and are composed of hereditary material surrounded by a protein coat
• Polysaccharides contribute to structural support and protection, serve as nutrient and energy stores
• Cells can be spherical, polygonal, cuboidal, or cylindrical, contain protoplasm encased in a cell membrane, have chromosomes containing DNA, and ribosomes for protein synthesis
• Taxonomy is the science of classifying living things, nomenclature assigns scientific names, classification arranges organisms into a hierarchy, and identification discovers and records traits of organisms
• The binomial system of nomenclature combines genus and species names, and scientific names are italicized in print and underlined by hand
• Classification ranks organisms from Domain to Species
• Phylogeny represents the natural relatedness between groups of living beings, and evolution involves hereditary information gradually changing through time
• COVID-19 evolved to infect humans from non-human animals due to small changes in genetic information
• An entirely new system of taxonomy based on domains includes Bacteria, Archaea, and Eukarya
• Bacteria with thicker walls are more resistant to antibiotics that target the cell wall.
• Some bacteria can be classified as "intermediate" because they do not fit neatly into either category.
• Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, while gram-negative bacteria have an outer membrane containing lipopolysaccharides.
• Gram staining is used to differentiate bacteria into two major categories (gram positive or gram negative) based on their ability to retain crystal violet dye during the staining process.
• Peptidoglycan consists of alternating sugars (N-acetylglucosamine and N-acetylluramic acid) crosslinked by short polypeptide chains.
• The cell wall is composed of peptidoglycan, which provides strength to the bacterial cell.
• The domain Eukarya contains all eukaryotic cells, including protists, fungi, plants, and animals.
• Prokaryotes have no nucleus or other membrane-bound organelles, while eukaryotes have these structures.