Microbiology final Exam Review

A comprehensive set of flashcards to review key concepts from microbiology lectures, covering microorganisms, their structures, functions, and impact on health, ecosystems, and biotechnology.

What is microbiology?

The study of microscopic organisms, such as bacteria, viruses, fungi, and protozoa.

What are microorganisms?

Tiny living organisms, including bacteria, viruses, fungi, and protozoa, visible only under a microscope.

What is the significance of studying microorganisms?

They can be pathogens causing diseases, beneficial for ecosystems, and important in biotechnology and medicine.

What are the common structures found in all living cells?

Cell membrane, cytoplasm, DNA/RNA, and ribosomes.

What is the function of the cell membrane?

Controls material exchange and maintains the internal environment of the cell.

What is the role of ribosomes in cells?

Facilitate protein synthesis.

How are microorganisms classified?

Based on cellular structure, genetic material, and biochemical properties.

What are prokaryotes?

Unicellular organisms that lack a nucleus.

What are eukaryotes?

Organisms that have a nucleus and can be unicellular or multicellular.

What distinguishes viruses from other microorganisms?

They are acellular and rely on hosts for reproduction.

What type of bacteria have a thick peptidoglycan wall?

Gram-positive bacteria.

What is an example of a gram-negative bacterium?

Escherichia coli.

What are mycoplasma?

Bacteria that lack a cell wall, such as Mycoplasma pneumoniae.

What are extremophiles?

Archaea that thrive in extreme environments.

What are the main types of fungi?

Yeasts and molds.

What are protists?

Diverse organisms that include algae and protozoa.

What are helminths?

Parasitic worms, such as Ascaris.

What is the function of antibiotics?

Used in medicine to fight bacterial infections.

What does bioremediation involve?

Using microbes to degrade pollutants and clean contaminated environments.

Who is known as the Father of Microbiology?

Antonie van Leeuwenhoek.

What did Louis Pasteur contribute to microbiology?

Germ theory, pasteurization, and vaccines.

What are Koch's postulates?

Criteria established to identify the causative agents of infectious diseases.

What was the first vaccine created?

The smallpox vaccine developed by Edward Jenner.

What is phagocytosis?

The process by which phagocytic cells engulf and digest pathogens.

What is the significance of the cell theory?

It states that all living organisms are composed of cells.

What are the essential macromolecules in biology?

Carbohydrates, proteins, lipids, and nucleic acids.

What is the role of catalase in cells?

Protects against oxidative stress by breaking down hydrogen peroxide.

What is the primary function of restriction enzymes?

Cut DNA at specific sites during genetic engineering.

What does the term 'GMO' stand for?

Genetically Modified Organism.

What is the purpose of the Kirby-Bauer test?

To assess antimicrobial susceptibility of bacteria.

Define 'pathogenic'.

Referring to organisms that cause disease.

What do we call the bacteria found in the human gut that assist with digestion?

Gut microbiota.

What is a microbiome?

The collection of resident microbes in and on the human body.

What are the effects of disruptions in the microbiome health?

Can lead to infections and various health issues.

What is the definition of an infection?

The invasion and multiplication of microbes that can cause disease.

What are host defenses against pathogens?

Include innate and adaptive immunity.

What constitutes innate immunity?

Immediate, nonspecific defenses, including physical barriers and cellular responses.

What role do vaccines play in immunity?

They stimulate the immune system to recognize and combat pathogens.

What is an endotoxin?

A component of the outer membrane of gram-negative bacteria that can cause severe inflammatory responses.

What do we call the first antibody produced in response to an infection?

IgM.

What is a prion?

A misfolded protein that causes neurodegenerative diseases.

What is a virulence factor?

Characteristics or components of a pathogen that contribute to its ability to cause disease.

How do antibiotics affect bacterial cells?

By targeting cellular processes essential for their survival.

What is horizontal gene transfer?

The transfer of genetic material between organisms in a manner other than traditional reproduction.

What is the central dogma of molecular biology?

DNA is transcribed to RNA, which is then translated to protein.

What is an operon?

A cluster of genes under the control of a single promoter, functioning together in gene regulation.

What is CRISPR technology?

A gene-editing tool that provides a way to alter DNA sequences and modify gene function.

What is the difference between mutualism, commensalism, and parasitism?

Mutualism benefits both organisms, commensalism benefits one without affecting the other, and parasitism benefits one at the expense of the other.

What are macronutrients?

Elements like carbon, hydrogen, oxygen, and nitrogen that are required in large amounts for life.

What does 'aseptic technique' refer to?

Methods used to prevent contamination by pathogens during laboratory procedures.

What is the role of ammonia in microbial metabolism?

It serves as a nitrogen source for synthesizing amino acids and nucleotides.

How does temperature affect microbial growth?

Microbial metabolism is often temperature-dependent, impacting growth rates.

What do we mean by the term 'selective media'?

Media designed to encourage the growth of certain types of microbes and inhibit others.

What is a hydrophilic molecule?

A molecule that is attracted to water and can interact with it.

What is the role of hydrogen bonds in DNA?

They stabilize the double helix structure of DNA.

What are some common disinfection methods?

Heat, radiation, and chemical germicides.

How do biofilms affect microbial communities?

They provide protection for microbes and allow them to communicate and share resources.

What conditions are conducive for antibiotic resistance to develop?

Overuse and misuse of antibiotics, leading to selective pressure on bacterial populations.

What is the significance of glycocalyx in bacteria?

It aids in attachment to surfaces and protects against phagocytosis.

What is the effect of pH on microbial growth?

Extreme pH levels can denature enzymes and affect cellular processes.

What are the metabolic processes involving glucose?

Glycolysis, fermentation, and aerobic respiration.

What is the role of flavin in metabolism?

It serves as a cofactor in various enzymatic reactions.

What are the differences between aerobic and anaerobic respiration?

Aerobic respiration uses oxygen; anaerobic does not and uses other molecules.

In gene therapy, what is the goal of replacing defective genes?

To correct genetic disorders.

What is the purpose of microbial antagonism?

To prevent the colonization of pathogens by resident bacteria.

How do antibiotics work against bacterial cell walls?

By inhibiting peptidoglycan synthesis, compromising the cell wall integrity.

What roles do T cells play in immune response?

They are involved in the destruction of infected or abnormal cells.

What are the steps involved in the infection process?

Adherence, invasion, multiplication, evasion, and damage.

What viral structure aids in host cell attachment?

Viral spikes or glycoproteins.

What do vaccines typically contain?

Antigens that stimulate an immune response.

How is antibiotic spectrum determined?

By whether the antibiotic is effective against a wide range or specific types of bacteria.

What is the term used for the collection of genes in a cell?

Genome.

What can cause spontaneous mutations?

Errors during DNA replication, exposure to chemicals or radiation.

What is the purpose of phase-contrast microscopy?

To enhance contrast for observing living cells.

How does natural selection relate to antibiotic resistance?

Bacteria survive by acquiring resistance genes, perpetuating resistant strains.

What is the function of common disinfectants?

They kill or inhibit the growth of pathogens on surfaces.

What is the importance of determining Minimum Inhibitory Concentration (MIC)?

It helps assess the effectiveness of antimicrobial agents.

What are examples of chemical agents used to control microbial growth?

Alcohols, phenolics, and heavy metals.

What factors can influence the effectiveness of an antimicrobial agent?

Concentration, exposure duration, environmental conditions, and microbial load.

What does 'disinfectant' specifically refer to?

Chemical agents that kill or inhibit pathogens on inanimate surfaces.

What are the characteristics of effective antiseptics?

Broad-spectrum activity, safety for humans, and effectiveness in the presence of organic matter.

What is the function of plasmids in bacterial cells?

They carry advantageous genes, such as antibiotic resistance.

What are capsules in bacteria?

Polysaccharide layers that protect bacteria from dehydration and immune responses.

How do microbes enter the host?

Through portals such as skin breaks, mucous membranes, and respiratory tracts.

What is the role of lipids in biological systems?

They provide energy storage and structural components of cell membranes.

What is the significance of the Kreb’s Cycle in metabolism?

It generates ATP, NADH, and FADH₂ from the oxidation of acetyl-CoA.

How do viruses replicate?

By infecting host cells and hijacking their cellular machinery.

What is defined as host range?

The variety of organisms a microbe can infect.

What is non-specific immunity?

Immediate defense mechanisms that do not target specific pathogens.

What defines the specificity of an antibody?

Its ability to bind specifically to a particular antigen.

What is the relationship between infection and disease?

Infection precedes disease, which results when the body cannot control the infection.

What is the main goal of genetic engineering?

To modify an organism's genome to achieve desired traits.

What is a beneficial use of yeasts in microbiology?

They are used in fermentation for making bread, alcohol, and other products.

What do we call medicines that specifically target viruses?

Antivirals.

What is a biofilm and its importance in microbial communities?

A collection of microorganisms that adhere to surfaces and are encased in a protective matrix; important for survival and functionality.

What factors can weaken host defenses against pathogens?

Poor nutrition, stress, lack of sleep, and certain medical conditions.

What distinguishes Gram-positive from Gram-negative bacteria?

Gram-positive bacteria have a thick peptidoglycan wall, while Gram-negative bacteria have a thinner peptidoglycan layer with an outer membrane.

Define symbiosis in the context of microbiology.

Interactions between different species of organisms, which can be beneficial, neutral, or harmful.

What are the effects of high temperatures on microbial cells?

They can denature proteins and disrupt cellular functions.

What method uses UV radiation for microbial control?

Surface sterilization.