CH 1 microorganisms

What are microorganisms?

Organisms that are too small to be seen with the unaided eye, including bacteria, fungi, protozoa, microscopic algae, and viruses.

What role do some microbes play in the environment?

They generate oxygen through photosynthesis and produce chemical products like ethanol, acetone, and vitamins.

What are pathogenic microbes?

Microbes that are disease-producing.

What is the microbiome?

A group of microbes that live stably on/in the human body, helping to maintain good health and prevent the growth of pathogenic microbes.

How many bacterial cells does an adult human harbor?

About 40 trillion bacterial cells.

What is normal microbiota?

The collection of acquired microorganisms on or in a healthy human being.

When do humans begin to acquire their microbiota?

Before birth.

What is the goal of The Human Microbiome Project?

To determine the makeup of typical microbiota of various areas of the body and understand the relationship between changes in microbiome and human diseases.

What is scientific nomenclature?

A system established by Carolus Linnaeus in 1735 where each organism has two names: the genus and the specific epithet.

How are scientific names formatted?

They are italicized or underlined, with the genus capitalized and the specific epithet in lowercase.

What does Escherichia coli describe?

The bacterium's habitat in the large intestine and honors its discoverer, Theodor Escherich.

What are the main types of microorganisms?

Bacteria, archaea, fungi, protozoa, algae, viruses, and multicellular animal parasites.

What are bacteria?

Prokaryotes that are single-celled, have peptidoglycan cell walls, and divide via binary fission.

What distinguishes archaea from bacteria?

Archaea lack peptidoglycan cell walls and often live in extreme environments.

What are fungi?

Eukaryotes with chitin cell walls that absorb organic chemicals for energy.

How do protozoa obtain nutrients?

They absorb or ingest organic chemicals and may be motile via pseudopods, cilia, or flagella.

What is the role of algae in the ecosystem?

They use photosynthesis for energy, producing oxygen and carbohydrates.

What are viruses?

Acellular entities that consist of a DNA or RNA core surrounded by a protein coat and replicate only in living host cells.

What are multicellular animal parasites?

Eukaryotic organisms that are not strictly microorganisms, including parasitic flatworms and roundworms.

What did Robert Hooke contribute to microbiology?

He reported that living things are composed of cells, marking the beginning of cell theory.

What is the debate over spontaneous generation?

The hypothesis that life arises from nonliving matter versus biogenesis, which states that living cells arise only from preexisting living cells.

What experiment did Francesco Redi conduct?

He filled jars with decaying meat to test spontaneous generation, using covered, opened, and sealed jars to observe the presence of maggots.

What experiment did John Needham conduct in 1745?

He put boiled nutrient broth into covered flasks, which resulted in microbial growth.

What did Pasteur use S-shaped flasks for?

To keep microbes out while allowing air in, demonstrating that microorganisms originate in air or fluids.

What was the First Golden Age of Microbiology?

A period from 1857 to 1914 characterized by discoveries related to microbes and disease, including the role of immunity and the development of vaccines.

What is fermentation?

The microbial conversion of sugar to alcohol in the absence of air, responsible for spoilage of food and beverages.

What is pasteurization?

The application of high heat for a short time to kill harmful bacteria in beverages without evaporating alcohol.

What did Agostino Bassi demonstrate in 1835?

He showed that a silkworm disease was caused by a fungus.

What is the Germ Theory of Disease?

The theory that specific diseases are caused by specific microorganisms, supported by the work of scientists like Pasteur and Koch.

What was Edward Jenner's contribution to vaccination?

In 1796, he inoculated a person with cowpox virus, leading to immunity against smallpox.

What is the origin of the word 'vaccination'?

It is derived from the Latin word 'vacca,' meaning cow.

What is chemotherapy in the context of microbiology?

The treatment of diseases caused by microbes using chemical agents, which can be synthetic drugs or antibiotics.

What significant discovery did Alexander Fleming make in 1928?

He discovered penicillin, the first antibiotic, by observing that Penicillium fungus killed Staphylococcus aureus.

What was Paul Ehrlich's 'magic bullet' concept?

The idea of a drug that could destroy a pathogen without harming the host, leading to the development of salvarsan for syphilis.

What role did Joseph Lister play in microbiology?

He applied Pasteur's work to use chemical antiseptics to prevent surgical wound infections in the 1860s.

What are Koch's postulates?

Experimental steps provided by Robert Koch to demonstrate that a specific microbe causes a specific disease.

What was the impact of antibiotics discovered in the 1940s?

Penicillin was tested clinically and mass-produced, revolutionizing the treatment of bacterial infections.

What was the significance of the milkmaid's story to Jenner's experiment?

It led Jenner to test the cowpox virus as a means of providing immunity against smallpox.

What is the definition of immunity?

The protection from disease provided by vaccination or recovery from the disease itself.

What was the role of Ignaz Semmelweis in disease prevention?

He advocated for handwashing to prevent the transmission of puerperal fever in the 1840s.

What did Pasteur demonstrate about spoilage bacteria?

He showed that spoilage bacteria could be killed by heat that did not evaporate alcohol in wine.

What are some problems associated with antimicrobial chemicals?

Some drugs can be toxic to humans, and there is a development of microbial resistance to antimicrobial drugs.

What is bacteriology?

The study of bacteria.

What is mycology?

The study of fungi.

What is parasitology?

The study of protozoa and parasitic worms.

What does immunology study?

Immunology is the study of immunity, including the use of vaccines and interferons to prevent and treat viral diseases.

Who classified streptococci based on their cell wall components?

Rebecca Lancefield in 1933.

What is virology?

The study of viruses.

What significant discovery did Dmitri Iwanowski make?

He discovered that the cause of mosaic disease of tobacco is a virus.

What is microbial genetics?

The study of how microbes inherit traits.

What did George Beadle and Edward Tatum demonstrate in 1941?

They showed that genes encode a cell's enzymes.

What is recombinant DNA?

DNA made from two different sources, enabling the manufacture of large amounts of human hormones and proteins.

What is microbial ecology?

The study of the relationship between microorganisms and their environment.

What is the primary use of microbes in sewage treatment?

Microbes are used to convert leftover liquid and organic materials into by-products such as carbon dioxide, nitrates, and methane.

What is bioremediation?

The use of microbes to degrade or detoxify pollutants such as oil and mercury.

What is the role of Bacillus thuringiensis in agriculture?

It is pathogenic to insects and is used as an alternative to chemical pesticides.

What are normal microbiota?

Microbes normally present in and on the human body that prevent the growth of pathogens and produce growth factors.

What are biofilms?

Complex masses of microbes that attach to solid surfaces, which can be beneficial or harmful.

What are emerging infectious diseases (EIDs)?

New diseases and diseases increasing in incidence, often due to factors like antibiotic resistance and modern transportation.

What virus caused the COVID-19 pandemic?

Severe acute respiratory coronavirus-2 (SARS-CoV-2).

What is the Zika virus known for?

It is spread by the Aedes mosquito and can cause mild disease, but infection during pregnancy can lead to severe birth defects.

What is MRSA?

Methicillin-resistant Staphylococcus aureus, a strain of bacteria resistant to many antibiotics.

What does the Ebola virus cause?

Fever, hemorrhaging, and intravascular blood clotting, transmitted via contact with infected body fluids.

What is the natural reservoir for the Marburg virus?

African fruit bats.

What is the significance of recombinant DNA technology in agriculture?

It enables genetically modified bacteria to protect crops from insects and freezing.

What is the role of vaccines in immunology?

Vaccines are used to prevent diseases by stimulating the immune response.

What is the impact of modern transportation on emerging infectious diseases?

It enables rapid dispersal of diseases across regions and countries.

What are the main components removed during sewage treatment?

Large solids are removed physically, and microbes convert organic materials into by-products.

What is the main focus of molecular biology?

The study of how genetic information is carried in molecules of DNA.