Exam 1: Ch 1: Intro to Microbes Flashcards
Scientific method
Observations → hypothesis → predictions → test → hypothesis either supported or rejected (rejected = back to hypothesis and repeat) (supported = start all over again w/new info)
Spontaneous generation
belief that some forms of life could arise from vital forces present in nonliving or decomposing matter; belief that living organisms didn’t necessarily come from living organisms all the time
(hay + cheese = mouse in barn); invisible forces lead to creation of life
Abiogenesis
“beginning in the absence of life”; supports spontaneous generation
Biogenesis
“beginning with life”; all living things arise from other living things; proved by Redi and Pasteur
Germ theory of disease
diseases are caused by germs and not b/c you have sinned or done something wrong; Pasteur and Koch contributed to this
Koch’s postulates
(4 steps) - everyone has to have the bacteria, have to isolate it and put it back into an organism and have same bacteria
−1) the suspected pathogen must be found in every case of the disease
−2) suspected pathogen must be isolated in pure culture
−3) inoculation of a sample of the culture into a health, susceptible animal must produce the same disease
−4) suspected pathogen must be recovered from the inoculated animals
Take pathogen out of dead mouse, isolate in culture, inoculate new mouse, mouse dies, take out pathogen, must be the same one
Organelles
small, double-membrane-bound structures that perform a specific function in a cell (includes nucleus, mitochondria and chloroplasts)(ribosome is only non-membrane bound organelle)
Taxonomy
grouping of organisms
Nomenclature
naming; assignment of scientific names to various taxonomic categories and individual organisms
Binomial nomenclature
uses 2 names: genus (capital) and species (lowercase)
Classification
orderly arrangement of organisms into a hierarchy of taxa
Macromolecules
4 main ones = carbs, lipids, proteins, nucleic acids
Monomers
subunits of macromolecules
Polymers
chains of various lengths made up of monomers
Carbohydrates
fast energy for cell
Polysaccharides
contribute structural support and protection; serve as nutrient and energy stores
Agar
polysaccharide used in preparing solid culture media for microbes
Peptidoglycan
polysaccharide linked to peptide fragments; found in bacterial cell walls (not archaeans; remember – if peptidoglycan found in cell wall = always bacteria, period)
Lipopolysaccharide
complex of lipid and polysacc responsible for symptoms of fever and shock (TSS)
Glycocalyx
outer surface of many cells; functions in attachment or as a receptor that receives external stimuli
Lipids
important for long term storage of energy ad protection in the cell; found in membrane of cell
Membrane lipids
naturally assume single and double layers (bilayers) which contribute to their biological significance in membranes
Hydrophilic (of lipid)
water loving region from the charge on the phosphoric acid-alcohol “head” of the molecule; outside the membrane
Hydrophobic (of lipid)
water fearing region inside the long, uncharged “tail” of the molecule formed by fatty acids; inside the membrane
Proteins
predominant organic molecule in cells
Amino acids
building blocks of proteins; all have a central core & a functional group (determines its role)
Peptide
molecule composed of short chains of amino acids
Polypeptide
contains an unspecified # of amino acids but usually has >20
Primary structure (1 degree) of proteins
the type, number and order of amino acids in the chain
Secondary structure (2 degree) of proteins
arises when functional groups exposed on the outer surface of molecule interact by forming hydrogen bonds → alpha helix & beta-pleated sheet; hydrogen bonds formed btwn close amino acids
Tertiary structure (3 degree) of proteins
created by additional bonds btwn functional groups; where there is bonding btwn distant amino acids
Quaternary structure (4 degree) of proteins
formed when more than one polypeptide forms a large multiunit protein; multiple subunits of tertiary structures; binding together of multiple tertiary structure proteins; not all proteins get to this state
Enzymes
protein catalysts for chemical reaction in cells; biological catalysts that lower activation energy; tools of the cell; 1 enzyme for 1 substrate
Antibodies
complex glycoproteins w/specific attachment regions for bacteria, viruses, and other microorganisms
Native state of protein
the functional 3D form
Denaturing
a protein becomes denatured if the protein structure is disrupted for some reason; becomes nonfunctional; disruptive agents: heat, alcohol, acid, disinfectants
DNA
contains the special coded genetic program w/detailed and specific instructions for each organism’s heredity
RNA
“helper” molecules responsible for carrying out DNAs instructions and translating the DNA program into molecules
Microbiology
area of biology that involves living things (microbes and microorganisms) that require magnification to be seen by the human eye
Evolution
changes that occur in organisms as they adapt to their environments over time
Theory (from a scientific perspective)
a thoroughly studied, well established, natural phenomenon that has undergone years of testing w/out being disproven
Pathogen
microbes that can cause various types of diseases or other health problems
Subunit
monomers; bind into chains called polymers thru polymerization
Importance of microbio
it’s the most important organism on earth; gives rise to everything
− Infectious disease control
− Nitrogen fixation – w/out nitrogen, we don’t have proteins or DNA
− Microbes shape our planet – the main forces that drive the structure and content of the soil, water and atmosphere
o Produce gases (CO2, NO, CH3) that regulate the temperature of the earth
o Underground community of microbes influence weathering, mineral extraction and soil formation
o Found in earth’s crust, polar ice caps, oceans, and bodies of plants and animals
o Live in places where other organisms cant survive & are most diverse group of organisms
o Cyanobacteria – the original way we have O2 on earth
− Food – fermented foods are very important; we cant wash microbes off of foods and microbes can attack foods (bread, cheese, milk products, fermented veggies, alcohol, spoilage/preservatives, plant and animal disease)
− Antibiotics – kill off certain microbes; microbes are also super easy to work with, no one cares if they die, and they give us a lot
− Molecular biology – gene cloning, genetic engineering, metabolism research
Prokaryotic
no nucleus and organelles
− Relatively simple in structure but complicated in function
− All bacteria are prokaryotes – different bacteria have different adaptations
− 1000x smaller
− Always single cellular
Eukaryotic
nucleus and organelles
− More complicated; has membrane bound organelles; has a membrane surrounded by a membrane
− 1000x larger
− Can be single cellular or multi cellular
Fundamental characteristics of a cell for living organisms
- Energy from the environment (photosynthesis, consumer, etc)
- Reproduction via DNA
- Evolve as a group (if the environment changes)
- Homeostasis (keep balance in the environment)
- At least one cell
Types of microorganisms (6)
helminthes, insects, protists, viruses, fungi, bacteria; living groups of microorganisms involve all of the above except viruses
Viruses
non living
− Don’t always reproduce via DNA – cant replicate w/out using host replication machinery
− Don’t need energy b/c they use us (host) to make it
− Do evolve
− No homeostasis/ability to control their structure or surroundings
− Don’t have cell structures (not a cell) don’t all have membrane, don’t have ribosomes or cytoplasm
− Because they are non living, they ARENT INCLUDED in the same taxonomical system as living organisms (they aren’t in one of the 3 domains)
Taxonomy
grouping of organisms
Domain(3) → Kingdom(6) → Phylum → Class → Order → Family → Genus → Species
Did King Philip Come Over For Good Soup
Kingdoms are inclusive, Species are exclusive (as you go down, it narrows)
Domains (3)
based on genetic similarities/off of rRNA sequence info
− Archaea – cells that live in extreme environments (high salt, heat, etc); NO peptidoglycan, no organelles
− Bacteria – true bacteria, peptidoglycan in cell wall, no organelles (if you have peptidoglycan in cell wall, you are bacteria – period)
− Eukarya – have nucleus and membrane bound organelles (ER, Golgi, mito/chloro); hosts
Kingdoms (6)
− Bacteria (domain: bacteria) − Archaea (domain: archaea) − Protista (domain: eukarya) − Plantae (domain: eukarya) − Fungi (domain: eukarya) − Animalia (domain: eukarya)
4 ways microbes have shaped our planet
- Changing the earth’s atmosphere from one w/out O2 to one with O2
- Formation of the ozone due to use of O2 for aerobic respiration
- Photosynthesis (accounts for >70% of the earths’ photosynthesis → majority of O2 in atmosphere)
- Temperature – maintenance and regulation
3 elements present in all 4 of the biological macromolecules
carbon, hydrogen, oxygen
Ferdinand Cohn
discovered heat-resistant bacterial endospores, which were the reason that heat would sometimes fail to eliminate all microorganisms
