chapter 1 microorganisms and microbiology Flashcards
microbiology
the study of microscopic organisms
microorganism definition
- size is measured in microns (1 μm = 1 x 10^-6 m)
- can only be seen in detail through microscope
microorganisms include…
bacteria, archaea, protists, fungi, microscopic animals, most parasites, viruses
virus
- referred to as particles
- not cellular, not alive
microbiology as a basic science
- understand basic life processes
- our understanding of basic biology (metabolism, etc.) is derived from studies using microorganisms
- microbial cells are easily cultured and attain high cell numbers, can be grown at low cost
microbiology as an applied science
- agriculture
- food
- disease
- energy/environment
- biotechnology
agriculture
N2 fixation, nutrient cycling, animal husbandry
food
food preservation, fermented foods, food additives
disease
identifying new diseases, treatment and cure, disease prevention
energy/environment
biofuels (methane and ethanol), bioremediation, microbial mining
biotechnology
genetically modified organisms, production of pharmaceuticals, gene therapy for certain diseases
prokaryotes
- single celled
- lack nucleus and other membrane bound organelles
- bacteria and archaea
eukaryotes
- single celled or multicellular
3 domains of life
bacteria, archaea, eukarya
characteristics of living systems
- metabolism
- reproduction
- differentiation
- movement
- communication
- evolution
metabolism
uptake of nutrients from environment, their transformation within the cell, elimination of wastes into the environment (cell is an open system)
reproduction
chemicals from environment are turned into new cells under directions of preexisting cells
differentiation
formation of new cell structure such as a spore, usually as part of cellular life cycle (some archaea and bacteria don’t undergo this)
movement
living organisms are capable of self-propulsion (some bacteria and archaea don’t move, env moves them)
communication
cells can communicate by means of chemicals that are released or taken up
evolution
cells contain genes and evolve to display new biological properties (phylogenetic tree shows evolutionary relationships)
chemical machines
enzymes
storehouses and processors of genetic information
DNA
microorganisms exist in populations
groups of organisms derived from a single parent cell following repeated division cycles
population
same species, same area
community
different species (populations), same area
microbial ecology
study of microorganisms in their natural environment and their relationships with one another
antiquity of microbial life
- Earth is 4.6 billion years old
- Universe is 13.8 billion years old
extent of microbial life
- first cells were prokaryotic
- eukaryotes didn’t arise until 2 bya
- macroscopic organisms didn’t arise until 1 bya
timeline of microbial life
- animals predate plants
- aquatic before terrestrial plants
- oxygen was toxic to organisms, our bodies can metabolize it because life forms adapted to these conditions
largest diversity
prokaryotes
cambrian explosion
- all phyla came from this time
- unparalleled emergence of organisms between 541 million and approximately 530 million years ago
microorg and disease agents
- all agents of infectious diseases are microorganisms
- increase in human life span due to reduction of direct and indirect mortality caused by infectious disease
- infectious diseases are major cause of mortality in developing countries
microorg and agriculture
- nitrogen cycling and nitrogen fixation are essential for crops (only carried out by microorgs)
- digestion of cellulose
- genetic engineering using microorgs imporves disease resistance and crop yields
microorgs and food
leading cause of spoilage and disease transmission in food, but also responsible for fermented foods
microorgs, energy, environment
- most fossil fuels exist bc of microorgs (petroleum, ethanol, natural gas)
- responsible for cleanup of toxic waste/oil spills
microorgs and genetic resources
vaccines, pharmaceuticals, specialty chemicals, development of disease resistance
Antoni van Leeuwenhoek (1693-1723)
cloth merchant became involved in lens grinding for examination of thread counts
Antoni van Leeuwenhoek key role
- developed first high magnification lenses
- first person to see and report bacteria
- developed first simple microscope (1684)
Louis Pasteur (1822-1895)
one of first microbiologists, research relating to production and preservation of wine
Louis Pasteur key role
- pasteurization: process developed to prolong shelf life of wine
- key role in “germ theory of disease”
- developed first rabies, cholera, and anthrax vaccines
- disproved “spontaneous generation” with swan neck flask experiments (you only get life from preexisting life)
swan neck flask experiments
memorize
Robert Koch (1843-1910)
german physician/microbiologist and first to demonstrate role of bacteria in causing disease
koch’s postulate 1
the suspected pathogenic microorganism should be present in all cases of the disease and absent from the same tissues/fluids of healthy animals
koch’s postulate 2
the suspected pathogenic microorganism should be grown in pure culture
koch’s postulate 3
cells from a pure culture of the suspected pathogenic microorganism should cause disease in a healthy animal
koch’s postulate 4
the microorganism should be re-isolated and shown to be the same as the original
