Microbio Exam 1

What is microbiology?

The specialized area of biology that deals with organisms too small to be seen with the naked eye.

What are the seven types of microorganisms studied in microbiology?

Bacteria, Archaea, Fungi, Protozoa, Helminths, Viruses, and Prions.

What are cellular microorganisms?

Microorganisms that HAVE cellular structures, including Bacteria, Archaea, Fungi, Protozoa, and Helminths.

What are noncellular microorganisms?

Microorganisms that LACK cellular structures, including Viruses and Prions.

What is the role of microbiologists?

They study cell structure and function, growth and physiology, genetics, taxonomy, evolutionary history, and interactions with the environment.

What does medical microbiology focus on?

It deals with microbes that cause diseases in humans and animals.

What is public health microbiology?

It monitors and controls the spread of diseases in communities.

What does immunology study?

The complex web of protective substances and cells produced in response to infection.

What is industrial microbiology?

It safeguards food and water and uses microbes to create products like amino acids, beer, drugs, enzymes, and vitamins.

What is agricultural microbiology?

It studies the relationships between microbes and farm animals and crops.

What is environmental microbiology?

It examines the effect of microbes on the earth's diverse habitats.

How have microbes impacted the development of Earth's habitats?

They’re impacted by being involved in the flow of energy and food through the earth’s ecosystems.

What distinguishes eukaryotes from bacteria and archaea?

Eukaryotes have a true nucleus, while bacteria and archaea do not.

What does it mean that bacteria are ubiquitous?

They can be found nearly everywhere

What is evolution?

The accumulation of changes that occur in organisms as they adapt to their environments.

What is the Theory of Evolution?

• Documented every day in all corners of the planet

• An observable phenomenon testable by science

• A label for a well-studied and well-established natural phenomenon

What role do photosynthetic microorganisms play in the atmosphere?

They contribute the majority of the oxygen to the atmosphere, primarily through bacteria and algae.

What is decomposition?

The breakdown of dead matter and wastes, accomplished by bacteria and fungi.

How do microbes influence soil, water, and atmosphere?

They drive the structure and content of soil, water, and atmosphere through gas production and complex associations with plants and animals.

What is the significance of microbial involvement in energy flow?

They’re deeply involved in the flow of energy and food through the earth's ecosystems.

What is one old way humans manipulate microorganisms?

Fermentation processes in food production.

What is one new way humans manipulate microorganisms?

Biotechnology applications, such as genetic engineering.

What are some traditional uses of microorganisms by humans?

Yeast for bread, wine, and beer production; fungi for cheese production; moldy bread for treating wounds.

What is biotechnology in relation to microorganisms?

The manipulation of microorganisms to create products in an industrial setting.

What is recombinant DNA technology?

A method that manipulates the genetics of microbes, plants, and animals to create new products and genetically modified organisms (GMOs).

What is bioremediation?

The introduction of microbes into the environment to restore stability or clean up toxic pollutants.

What is a pathogen?

Any agent such as a virus, bacterium, fungus, protozoan, or helminth that causes disease.

Name three diseases caused by microorganisms that are top causes of death in the U.S.

COVID-19, influenza, pneumonia.

What is the global impact of malaria?

It kills about 450,000 people every year and is transmitted by mosquitoes.

What are some examples of emerging and reemerging infectious diseases?

SARS-CoV-2, Ebola, AIDS, hepatitis C, and viral encephalitis.

What are some diseases once considered noninfectious that are now linked to microbes?

Gastric ulcers (Helicobacter pylori), certain cancers, diabetes (Coxsackievirus), and multiple sclerosis.

How can weakened immune systems affect disease susceptibility?

It causes more susceptibility to infections by common microbes not pathogenic to healthy individuals.

What are the two types of acellular microorganisms?

Viruses and prions.

How do bacterial and archaeal cells compare in size to eukaryotic cells?

Bacterial and archaeal cells are about 10x SMALLER than eukaryotic cells.

What is the significance of organelles in eukaryotic cells?

Their functional specialization, compartmentalization, and evolutionary advantages

What is the structure of viruses?

Composed of hereditary material (DNA or RNA) wrapped in a protein covering, sometimes enveloped by a lipid membrane.

What is a prion?

A small protein folded in intricate ways that can behave like microorganisms and be transmitted between humans.

What is the burden of human disease caused by microbes in developed vs. developing countries?

Developing countries face higher rates of infectious diseases.

What is the role of the scientific method in microbiology?

It’s crucial for developing hypotheses, conducting experiments, and validating results in microbiological research.

What is the historical significance of the development of microbiology?

It’s evolved since the 1600s, leading to significant discoveries impacting health and disease management.

What are some connections between diseases considered noninfectious and microbes?

Gastric ulcers, certain cancers, and chronic diseases like obesity have been linked to microbial infections.

What are some methods of preventing malaria infection?

Use of bed nets

What caused the belief in spontaneous generation?

Certain foods spoiled or caused illness, leading to the idea that life could arise from non-living matter.

Who disproved spontaneous generation?

Louis Pasteur

What was Robert Hooke known for?

First observations of microbes in the 1600s.

What did Antonie van Leeuwenhoek contribute to microbiology?

He made a crude microscope and drew 'animalcules' from rainwater and his teeth.

What advancements characterize modern microscopes?

More refined lenses, condensers, finer focusing devices, and built-in light sources.

What significant biological technique was invented in the 1980s?

Polymerase Chain Reaction (PCR)

What is the scientific method?

A general approach taken by scientists to explain natural phenomena through observation and experimentation.

What is a hypothesis?

A tentative explanation that can be supported or discredited by observation or experimentation.

What happens if experiments do not support a hypothesis?

The hypothesis or parts of it are rejected or modified.

What is a theory in scientific terms?

A collection of statements or concepts that explains a natural event and has stood the test of time.

What are characteristics of effective scientists?

Curiosity, open-mindedness, skepticism, creativity, cooperation, and readiness to revise views.

What did John Tyndall discover?

He found that microbes in dust and air have high heat resistance.

What did Robert Koch establish?

He linked specific microorganisms to specific diseases and established proofs for the germ theory of disease.

What is the binomial system of nomenclature?

A system that combines the genus name (capitalized) and species name (lowercase), both italicized.

What are the eight taxonomic categories in biological classification?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What are the three domains of life?

The 3 are Bacteria, Archaea, Eukarya

What is taxonomy?

The science of classifying biological species, developed by Carl von Linné.

What is phylogeny?

The natural relatedness between groups of living things based on evolution.

What did the discovery of ribosomal RNA (ssuRNA) contribute to?

It allowed in-depth study of genetic material and established three domains of life.

What is the significance of aseptic techniques?

They were developed to prevent infections in medical settings, notably by Joseph Lister.

What did Dr. Ignaz Semmelweis demonstrate?

He showed that handwashing reduced infections in maternity wards.

What is the role of the scientific method in science?

It provides a structured process for experimentation, analysis, and testing to support or refute hypotheses.

What is the importance of publishing experimental results?

It allows results to be tested and retested by other investigators, contributing to scientific knowledge.

What is the germ theory of disease?

The theory that specific diseases are caused by specific microorganisms.

What is the significance of the human microbiome?

It represents the genetic identification and understanding of the diverse microorganisms living in and on the human body.

What structures do all bacteria possess?

Cytoplasmic membrane, chromosome/nucleoid, ribosomes, and cytoplasm.

What are four structures that SOME bacteria possess?

Cell wall, outer membrane, S layer, glycocalyx/capsule.

What are the three major shapes of bacteria?

Coccus (spherical), bacillus (rod-shaped), and curved (vibrio, spirillum, spirochete).

What is pleomorphism in bacteria?

Variations in size and shape among cells of a single species due to nutritional or genetic differences.

What is the function of the bacterial cell wall?

Provides structural support and shape

What is the role of ribosomes in bacteria?

Sites of protein synthesis.

What is the average size of bacteria?

Approximately 1 µm.

What is the function of fimbriae?

Aid in adhesion to surfaces and cells.

What is a flagellum?

A specialized appendage for motility that pushes the cell forward.

What is chemotaxis?

Movement of bacteria in response to chemical signals.

What is positive chemotaxis?

Movement toward a favorable stimulus.

What is negative chemotaxis?

Movement away from a harmful repellent.

What are the three parts of a bacterial flagellum?

Filament, hook, and basal body.

What is the function of the glycocalyx?

Functions in protection, adhesion, and reception.

What is an endospore?

A dormant body formed within a cell allowing survival under adverse conditions.

What is a pilus used for?

To draw another bacterium close for DNA transfer (conjugation).

What are nanowires/nanotubes?

Thin tubular extensions allowing electron or nutrient transmission between cells.

What is the role of the outer membrane in some bacteria?

Controls material flow and contains lipopolysaccharide (LPS), which can cause immune reactions.

What is the function of the actin cytoskeleton in bacteria?

Contributes to cell shape with long protein fibers encircling the cell.

What is the significance of biofilms?

Microbial habitats where bacteria live in cooperative associations.

What is the term for pairs of cocci?

Diplococci.

What are tetrads in bacterial arrangements?

Groups of four cocci.

What are streptococci?

Chains of a few to hundreds of cocci.

What is the term for a chain of rod-shaped bacteria?

Streptobacilli.

What is the role of the S layer?

Provides protection in hostile environments.

What is the difference between a 'run' and a 'tumble' in bacterial movement?

'Run' is a straight movement, while 'tumble' is a random change in direction.

True or False: Bacterial fimbriae are used for conjugation.

False - Pili are used for conjugation.

What are the main structural differences between capsules and biofilms?

Capsules are well-defined structures surrounding the cell, while biofilms are complex communities of bacteria adhering to surfaces.

What are the two main types of bacterial envelope structure?

Gram-positive and Gram-negative.

Why are gram-positive cell walls stronger than gram-negative cell walls?

B/c they have a thicker peptidoglycan layer.

What substance in the envelope structure of some bacteria can cause severe symptoms in humans?

Lipopolysaccharide (LPS).

What is the structure of peptidoglycan?

Repeating long glycan chains cross-linked by short peptide chains.

What is unique about the cell walls of Mycobacterium and Nocardia?

They contain mycolic acid, contributing to pathogenicity and chemical resistance.