History, Scope, & Classification / Scope of MicroBiology Learning Objs (1.1)
S3. Describe the roles microorganisms play in the following biogeochemical cycles: carbon.
- Carbon Fixation - synthesis of carbohydrate from CO2 in photosynthesis - photosynthetic microorganisms series of processes that converts CO2 (carbon dioxide) to organic substances and back to CO2
S9. Describe examples of fossil, molecular, & morphological evidence of the evolution of microorganisms.
Although individual prokaryotes could not be fossilized (or their fossils difficult to find), prokaryotic communities formed structures that could be fossilized • Early prokaryotes formed sediment-trapping-films that could be fossilized forming rocks called stromatolites - rocklike pillars 3.5 billion years old • Modern-day stromatolites still form in warm, salty, shallow bays • Prokaryotes were sole inhabitants from 3.5 to 2.1 billion years ago
S1. Explain why microorganisms are the foundation for all life on earth.
Microorganisms have roles in all the principal ecological niches: producers, consumers, and decomposers. Without them there could be no life as we know it. 1. Nutrient Cycles - essential for generation of nutrients - gas fixation 2. Food Webs - forms the base of food webs providing both food and gases (0₂, CO₂) needed for life 3. Recycling of Nutrients - involved in decay process used in the treatment of sewage & other waste disposal 4. Human Health - microorganisms living on & in our bodies limits introduction & spread of pathogens in the body
H2 Explain the importance of the light microscope to microbiology.
Microbiology started w/ invention of microscope; allowed scientists to view microorganisms for the first time. • This advance led to theories on the origin of life and disease
Describe the use of microorganisms in food production,
Microorganisms used directly as food - mushrooms (fungus); protists (seaweed) Natural - use of microorganisms to produce products as part of their metabolism - Food production (bread, cheese, wine, etc.)
Define describe and explain Bt
Natural: Bacillus thuringiensis (bacterium) produces a protein (Bt) toxic to caterpillars but not to other animals. Bt can be collected for pesticide use. • Engineered: Bt protein gene is isolated & inserted into plant genome so plant produces Bt protein becoming resistant to caterpillars
S3. Describe the roles microorganisms play in the following biogeochemical cycles: nitrogen
series of processes that converts N2 (nitrogen) to organic substances and back to N2 - Nitrogen Fixation - conversion of N2 gas to ammonia, nitrate, or nitrite. Ex: Rhizobium -- a nitrogen fixing bacterium that forms an endosymbiotic relationship with plants resulting in the formation of nodules on the roots.
H9. Describe the contribution of Edward Jenner to the process of vaccination.
• 1796 - Edward Jenner used cowpox to inoculate (used cowpox pustule scrapings on a needle to scratch the skin) an 8-year-old volunteer who subsequently became immune to smallpox. Immunity is protection from disease involving cells and antibodies produced by the immune system.• The process of introducing an avirulent pathogen (does not cause the disease) that is similar to the virulent pathogen (causes disease) to stimulate the immune response is known as vaccination. • Vaccinations are also produced using dead pathogens or only part of the pathogen (antigen). Cowpox related to smallpox
H12. Describe the contributions of Rosalind Franklin, to the discovery of the double-helical structure of DNA.
• 1950's - Maurice Wilkins and Rosalind Franklin determined the biochemical features (dimensions) of DNA using X-ray crystallography • X-ray crystallography patterns indicated that DNA composed of two strands arranged in a helical pattern - double helix • One turn of the double helix was 3.4 nm consisting of 10 nucleotides (0.34 nm between each) and the radius of the double helix is 1 nm.
S10. Describe the following major events in the evolution of life on earth: the evolution of respiration.
• Aerobic cellular respiration produces more energy allowing organisms to become larger and more complex
H1 Characterize microbiology as a science.
• Microbiology is the study of microorganisms that includes bacteria, viruses, fungi, protozoans, Prokarys & eukarys • Fields w/in microbiology include: Bacteriology - study of bacteria; Virology - study of viruses; Immunology - study of body's defense against disease; Molecular Biology - study & manipulation of DNA; Environmental microbiology - study of microorganisms & the environment
S8. Describe the evolution of the first cells and& how they diverged into the 3 domains of life known today.
• Primordial cell may have had characteristics in common w/ Bacteria & Archaea • Bacteria & Archaea diverged & developed different characteristics, for example, Bacteria developed peptidoglycan cell walls. • Eukaryotes may have evolved from early Archaea, became larger, & developed endosymbiotic relationships with Bacteria/Archaea leading to organelles (endosymbiotic theory)
H11. Explain the importance of the discovery of the double-helical structure of DNA.
• The double helix provided an understanding of DNA replication & how DNA could specify proteins (transcription & translation) ie. specify the characteristics of organism • DNA is the hereditary material of all living cells, composed of 2 complementary strands of nucleic acid; • Microorganisms were used to determine that deoxynucleic acid (DNA) is the hereditary material (genes) of all life
S5. Recall the structure and function of prokaryotic cells.
Comes from the Greek word pre-nucleus One circular chromosome not in a membrane (haploid) No histones or organelles, complex polysaccaride (peptidoglycan) cell wall and binary fission (less complex cell division)
H6. Describe the germ theory of disease.
Germ Theory of Disease -- microorganisms can cause disease The recognition of the Germ Theory of Disease as well as the presence of microorganisms in the environment contributed to the development of aseptic technique.
S!) Describe the following major events in the evolution of life on earth:
If correct, the evidence provided would be the major events.
Describe the use of microorganisms in manufacture of chemotherapeutics & other industrial products
Is The treatment of disease using chemical agents or drugs that are selectively toxic to the causative agent of the disease, such as a virus, bacterium, or other microorganism. Like antibiotics • Engineered - introduction of exogenous DNA into microorganisms, plants, and animals to produce products they did not naturally produce or to increase their survival or growth rate. - Recombinant DNA technology; Genetic Engineering
S2 Describe the use of microorganisms in bioremediation,
Is the use of either naturally occurring or deliberately introduced microorganisms or other forms of life to consume and break down environmental pollutants, in order to clean up a polluted site. • Bacteria degrade organic matter in sewage • Bacteria degrade or detoxify pollutants such as oil and mercury
What is fermentation
It is the conversion of sugars into alcohol in the absence of air producing energy for the microorganism
S7. Describe the evidence that supports the endosymbiotic theory.
Key evidence supporting an endosymbioticorigin of mitochondria and plastids (chloroplasts): - Both two membranes with the inner membranes more similar to plasma membranes of prokaryotes - Binary division is similar in these organelles and some prokaryotes - These organelles transcribe and translate their own DNA & genomic DNA is circular as in prokaryotes - Their ribosomes are more similar to prokaryotic than eukaryotic ribosomes
H3 Describe the contribution of Anton van Leeuwenhoek to the invention of the light microscope
Leeuwenhoek was 1st to develop a microscope capable of viewing microorganisms, (he named "animalcules") -was unsure how these organisms arose or reproduced.
H7. Describe the contributions of Ignatz Semmelweis and Joseph Lister to the development of aseptic technique.
1840s - Ignaz Semmelweis demonstrated that disinfection of physician's hands prevent transmission of puerperal fever (childbirth fever) in obstetric wards. He is credited as the first to control nosocomial infections. (Nosocomial infection - infection obtained while in a hospital) 1860s - Joseph Lister • applied germ theory to surgery and believed that microorganisms could cause surgical wound infections -- demonstrated that infection of surgical wounds could be controlled using diluted carbolic acid (phenol) solution as a disinfectant.
H10. Describe the contribution of Alexander Flemming to the development of chemotherapy.
1928: Alexander Fleming discovered the first antibiotic, he observed that Penicilliumchrysogenum fungus made an antibiotic, penicillin, that killed Staphylococcus aureus • 1940s: Penicillin was tested clinically and mass produced Chemotherapy is the treatment of disease by chemical substances 1. Antibiotics - organic molecules produced by microorganisms that inhibit microbial growth 2. Synthetic Drugs - treatments consisting of chemically produced compounds 3. Natural compounds - compounds produced in nature that were discovered to be effective against disease, either by modern methods, trial and error, or folklore (quinine). •
H 12) Describe the contributions of Francis Crick and James Watson to the discovery of the double-helical structure of DNA
1953 - James Watson & Francis Crick used nucleotide models, & other information to propose a DNA structure • They also determined that Adenine (A) could base pair most effectively with Thymine (T) & Guanine (G) could base pair most effectively with Cytosine (C) • The Watson and Crick DNA model consists of 2, antiparallel DNA strands arranged in a helix with the bases inside & phosphate groups outside, where base pairing rules are A:T and G:C.
S3. Describe the roles microorganisms play in the following biogeochemical cycles
Biogeochemical cycle - Recycling of chemical elements from gas or element into organic molecules, & then back again to elements / gas Bacteria recycles C, nutrients, S, & P that can be used by plants & animals
S11. State the importance of three areas included in the study of taxonomy: classification, identification and nomenclature.
Classification is the grouping of living organisms according to similar characterisitics Nomenclature refers to binomial nomenclature where every organism is assigned two names, the genus name and the specific epithet (species)
S6. Explain the endosymbiotic theory of the evolution of eukaryotes.
Date back 2.1 billion years, These cells have a nuclear envelope, mitochondria, endoplasmic reticulum, and a cytoskeleton. The endosymbiont theory proposes that mitochondria and plastids (chloroplasts and related organelles, all except reibosomes) were formerly small prokaryotes living within larger host cells The prokaryotic ancestors of mitochondria and plastids probably gained entry to the host cell as undigested prey or internal parasites • In the process of becoming more interdependent, the host and endosymbionts would have become a single organism • An endosymbiont is a cell that lives within a host cell
S4. Recall the structure and function of eukaryotic cells.
Eukaryote comes from the greek words for true nucleus. Paired chromosomes in nuclear membrane (diploid), Histones, Organelles, Chemically simple cell walls, and has a Mitiotic Spindle (complex cell division)
Define, Describe and explain Rhizobium
Ex: Rhizobium -- a nitrogen fixing bacterium that forms an endosymbiotic relationship with plants resulting in the formation of nodules on the roots.
H8. Explain the process of pasteurization.
Pasteur hired by beer & wine makers to examine spoilage. Production of alcohol in b & w was thought to be due to chemical process. He discovered & proved that microorganisms were responsible for fermentation & went on to demonstrate that certain fermentations (alcohol, lactic, butyric) were caused by specific yeasts & bacteria. In order to prevent the contamination of b & w by undesirable bacteria, Pasteur developed pasteurization - carefully heat the liquid (milk, beer, wine) to a temp just sufficient to kill undesired bacteria -- but not desirable yeast -- & then cool the liquid.
S10. Describe the following major events in the evolution of life on earth: the evolution of photosynthesis, the evolution of respiration, and endosymbiosis.
Photosynthesis - produced oxygen & changed primordial Earth's atmosphere from a reducing atmosphere to oxidizing atmosphere and also facilitated evolution of aerobic cellular respiration
H4. Compare and contrast the competing theories of spontaneous generation and biogenesis.
SG - life could arise from nonliving matter A factor in SG is the "vital force" in the air --absence of air would result in the absence of spontaneous generation. Biogenesis - life arises from pre-existing life. Living cells could only arise from living cells by reproductive processes
H5. Describe the experiments of Francesco Redi and Louis Pasteur that support the theory of biogenesis.
To determine if maggots arose spontaneously from decaying meat, Redi placed meat into two containers; one container was one container was covered with a fine mesh allowing air to enter (i.e. "vital force") but not flies and the other was open allowing flies to enter. Meat in the mesh-covered container group did not have maggots, but meat in the open container group did Pasteur From the swan neck flask experiment, Pasteur demonstrated that microbes are present in the air and on all surfaces and thus demonstrated that the theory of biogenesis applied to microorganisms
