Micro Ch.1 SG
Explain what Antony van Leeuwenhoek accomplished and why it was important.
- Made a single lens microscope - Observed Animalcules (bacteria, protozoa in a lake water droplet)
What experiment disproved the notion that vital force in air was responsible for spontaneous generation?
- Pasteur's swan neck bottles
Explain the concept of spontaneous generation and the contributions of Redi, Pasteur and Tyndall in disproving it.
- Robert Hook=> discovered microscopic mushroom (common bread mold). Described how to build a microscope. - Redi => Found that worms on rotted meat came from flies rather than the meat itself. He covered the meat with gauze which prevented the flies from laying eggs. - John Needham => showed that flasks containing various broths that were boiled and sealed with a cork gave rise to microorganisms (supported spontaneous generation). - Spallazani => Conducted a similar experiment as Needham, with 2 differences; he boiled the broths longer and sealed the flasks by melting their necks. Found that the broths remained sterile if air did not touch it. Pasteur => Demonstrated that air contains micro organisms (by filtering air through a cotton plug). Found that the micro organisms were identical to the ones found in broth. constructed swan neck flasks that kept liquids within sterile even when open to air. These experiments disproved spontaneous generation. Tyndall => Proved Pasteur correct. Discovered that different broths require different boiling times. Discovered that hay contains heat resistant microbials. Cohn => Discovered endospores (heat resistant bacteria). Koch => discovered anthrax was caused by spore forming bacteria. - Organisms containing endospores are generally found in soil which would explain their presence in hay.
What conclusions could Tyndall reach on the properties of the agent that entered the broth from hay?
- That some microbes are heat resistant
What do we know for certain about microorganisms? What are we uncertain about?
- We can identify and distinguish between the different types of microorganisms and place them in a category such as prokaryotes and eukaryotes. Less than 1% of prokaryotes have been studied. With technology advancements we are entering the second golden age.
Give two reasons why it took so long to disprove spontaneous generation.
-It was difficult to replicate experiments and get the same results because their sterilization techniques weren't as advanced as they are now
When did Father Spallanzani perform his experiement
1776
What year did Pasteur Perform his experiments
1861
Who was John Needham
A catholic priest who boiled broths and found that they still contained microbes
What is a Prion
A misfolded protein
What two main things did Pasteur demonstrate with his experiments.
Air contains microorganisms Special swan neck glass bottles prevented microbes from entering the broth.
Who was the first person to observe bacteria and when?
Antoine Van Leeuwenhoeke in 1674
What are the differences between Archaea and Bacteria?
Archaea don't have peptidoglycan in their cell walls. ribosomal RNA sequence Differences in Chemical composition
What are the Three domains of living organisms
Bacteria, Archea and Eucarya
Describe the defining features present and absent in Bacteria, Archaea and the Eucarya. Be able to classify organisms into the correct domain. (EX: roundworm, E. coli bacteria, beetle, algae, microscopic organism growing in thermal vents, humans, apple tree). List microbiologically important eukaryotes.
Bacteria: Members of the domain Bacteria are prokaryotes, meaning they are single-celled organisms consisting of a prokaryotic cell (meaning "pronucleus"). This cell type typically doesn't have a nucleus, rather a nucleoid. Most bacteria have specific shapes. They typically have rigid cell walls that contain peptidoglycan, a compound unique to bacteria. They typically move via flagellum. They typically multiply by binary fission (process by which the cell enlarges and separates into two cells, usually identical to the original. Size: 0.3-2um Nuclear Membrane: No Cell Wall: Peptidoglycan present Membrane-bund organelles: No Where found: in all environments. Archaea: Like bacteria they have a prokaryotic cell structure. They have similar shapes, sizes, and appearances as bacteria. They also multiply by binary fission, move via flagellum, and have rigid cell walls. Archaea are more closely related to humans rather than bacteria. Some of the significant differences between Archaea and bacteria are that archaea's cell walls don't contain peptidoglycan. An interesting feature of archaea is their ability to grow in extreme conditions that would kill most organisms. Size: 03-2um Nuclear Membrane: No Cell Wall: No Peptidoglycan Membrane-bund organelles: No Where found: in all environments. Eucarya: Members of the Eucarya are eukaryotes, meaning they are composed of one or more eukaryotic cells ("true nucleus"). These cells have membrane bound nucleus and other organelles, making them far more complex than prokaryotes. The microbial members of the Eucarya include algae, fungi, and protozoa. Algae and protozoa are also referred to as protists. Helminths (multicellular parasites) are also mentioned in the text as they kill millions of people around the world, especially in developing nations. These include roundworms and tapeworms. Size: 5-50um Nuclear Membrane: Yes Cell Wall: No Peptidoglycan Membrane-bund organelles: Yes Where found: in environments that are not extreme.
When were most pathogenic baterica identified?
Between 1876-1918
Are Eucarya prokaryotes or eukaryotes?
Eukaryotes
True or False: Fungi and Protozoa have a rigid cell wall
False
True or False: Viruses, viroids, and prions are living
False
What are three reasons that diseases can re-emerge
Fear of Vaccinations Travelers Resistant strains of the disease Changing Characteristics of a population
Who discovered Endospores
Ferdinand Cohn
What are three vital activities of Microorganisms
Fixation of Nitrogen, Replenishment of O2 Break down undigested materials
What are the applications of Microbiology
Food Production Biodegradation Commerical Valuable products from bacteria Biotechnology Medical Microbiology
Give examples of how microbes can harm, and help, humans. Provide examples of microbes use in food production, cleaning pollution, and in manufacturing. Provide a few examples of historical events in medical microbiology and some of the current struggles.
Food production: - By 1500 B.C. Egyptians used a complex procedure for fermenting cereal grains to produce beer. Today we use the same fundamental techniques to make beer and other fermented drinks. - Virtually every population that raised cows and goats also developed procedures to ferment milk. This allowed them to make foods such as yogurt, cheeses, and buttermilk. Toda, the bacteria added to some fermented milk products are touted as probiotics, protecting against intestinal infections and bowel cancer. Biodegradation: - Microorganisms degrade environmental pollution. Bacteria also lessen he damage from oil spills. - In some cases, microorganisms are added to pollutants to hasten their decay, process called bioremediation. Commercially valuable products from bacteria: Although these same products can be made in factories, bacteria often generate them faster and cheaper. For example, different bacteria produce: - Cellulose: used in stereo headsets - Hydroxybutyric acid: used in the manufacture of disposable diapers and plastics. - Ethanol: used in biofuel - Hydrogen gas: used as possible biofuel - Oils: used as a possible biofuel - Insect toxins: used in insecticides - Antibiotics: used in the treatment of disease - Amino Acids: used a dietary supplement. Biotechnology, the use of microbiological and biochemical techniques to solve practical problems, depends on microorganisms. Medical Microbiology: Past: -Between 1876 and 1918, most pathogenic bacteria were identified, and early work on viruses had begun. Over the last 100 years, improvements in human health have been due largely to using antibiotics to treat infectious diseases, and vaccines to prevent them. - In recent times, an active worldwide vaccination program eliminated the smallpox disease in nature, with no cases being since 1977. However, the possibility that the smallpox virus could be used in bioterrorist attacks is a great concern. - Now less than 100 people worldwide die from plague in a typical year. This dramatic decrease is primarily a result of controlling the rodent population that harbors the bacterium. In addition, the discovery of antibiotics in the twentieth century made the isolated outbreaks treatable. Present: - Although progress has been impressive against bacterial diseases, much more still needs to be done. This is especially true for the treatment of viral infections and diseases associated with poverty. - Respiratory infections and diarrheal diseases cause most illness and deaths in the world today. - Even in wealthy developed countries with their sophisticated healthcare systems, infectious diseases remain a serious threat. - In the United States, about 740 million cases of infectious diseases occur each year, leading to 200,000 deaths and costing tens of billions of dollars.
Who was the first one to challenge spontaneous generation
Francesco Redi
What is the difference between fungi and algae when it comes to gaining energy?
Fungi gain energy from breaking down organic materials rather than photosynthesis
what experiment did Redi Perform to disprove Spontaneous Generation
He put a fine layer of gauze over a piece of meat to prevent flies from laying their eggs on the meat.
What are Endospores?
Heat resistant forms of bacteria
Spontaneous generation
Hypothesis stating that life could arise from nonliving matter.
What will be the focus of the new Golden Age of Microbiology? Identifying unknown members of the microbial world.
Identifying unknown members of the microbial world.
What must an organism need to be alive?
It must be composed of one or more cells to be alive
What percentage of microbal speices can be grown in the lab
Less than 1%
What are Pathogens?
Microbes that can cause disease.
What are Microbes?
Microorganisms and other infectious agents
Where does the genetic information reside in bacteria?
Nucleoid
What experiment disproved the notion that vital force in air was responsible for spontaneous generation
Pasteur's swan neck bottles
Archaea are prokaryotes or eukaryotes
Prokaryotes
members of the bacteria domain are prokaryote or eukaryote?
Prokaryotes
What are some examples of Helminths
Roundworms, and tapeworms
Are Algae single celled or multicelled
Some are single celled and others are multicelled
How was Father Spallanzani's experiment different from John Needham?
Spanllanzani boiled the samples longer and melted the glass neck close.
What is spontaneous generation
That microrganisms arise from non living material
What conclusions could Tyndall reach on the properties of the agent that entered the broth from hay?
That some microbes are heat resistant
Who is Louis Pasteur
The French chemist considered by many to be the father of modern microbiology.
What is an interesting feature that many Archaea have
The ability to grow in extreme environments
What is Normal Microbiota?
The normal microorganism colonies on and in humans
Where are organisms that produce endospores commonly found
The soil
What do Viroids consist of
They consist of only a single short peice of RNA
Who are Sliden and Swan
They stated that plants and animals have cells
What are the microbial members of the Eucarya domain
algae, fungi and protozoa, Helminths
What do all algae have in common?
all contain chloroplasts.
Why did pasteur not run into problems with endospores
because he used only broths made with sugar or yeast extract
Why are Microorganisms used as model organisms
because they display the same fundamental metabolic and genetic properties as higher life forms.
what is the size of protozoas
microscopic
Where is algae usually found
near the surface of either fresh or salt water
What does a Viruses consist of?
nucleic acid packaged within a protein coat
what is the source of energy for protozoa
organic compounds
What are typical bacterial cell walls made of
peptidoglycan
Give two reasons why it took so long to disprove spontaneous generation
see back of book
What do Archaea and Bacteria have in common?
similar shapes and sizes multiply by binary fission, move primarly by flagella and have cell walls
What is the cell organization of protozoa
single-celled
What are the common shapes of bacteria
spherical cylindrical spiral
What did Tyndall discover
that some microbes are readily killed by boiling and others are heat resistant
What are obligate intracellular parasites
viruses, Viroids