Microbiology Lecture Notes Review - BIOL 2400

These flashcards cover key microbiological concepts, definitions, and important figures that are essential for understanding the subject matter in preparation for exams.

What are microorganisms?

Organisms that require a microscope to view.

Definition of microbiology?

The study of small organisms.

What is taxonomy?

The science of classification, description, identification, and naming of living organisms.

What are the major taxonomic ranks?

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

Which type of microorganisms can include multicellular eukaryotes?

Fungi, Algae, and Helminths.

What is the interchangeable term for microorganisms?

Microbes.

What is the structural difference between prokaryotes and eukaryotes?

Prokaryotes do not have a nucleus; eukaryotes do.

What is unique about the cell wall of Archaea?

It is composed of pseudopeptidoglycan.

What is the significance of binomial nomenclature?

It is the system of naming organisms using genus and species names.

How is a scientific name formatted?

The genus name is capitalized and italicized, while the species name is lowercase and italicized.

What is the difference in species definition between eukaryotes and prokaryotes?

Eukaryotic species are defined as organisms that can interbreed, while prokaryotic species are a population of cells with similar characteristics.

What role do microbes play in the ecosystem?

They are crucial for recycling nutrients and supporting food chains.

What are pathogens?

Microbes that cause disease.

How do microbes contribute to agriculture?

By fixing nitrogen and aiding in nutrient cycling.

What is bioremediation?

The use of microbes to clean up contaminants in the environment.

Who is Robert Hooke?

The first scientist to observe cells.

What did Anton van Leeuwenhoek discover?

Bacteria and protozoa, which he called 'animalcules'.

What is the function of a compound light microscope?

To magnify objects using light through two lenses.

Define resolution in microscopy.

The ability to distinguish two separate entities in a specimen.

What is the difference between resolution and contrast?

Resolution refers to clarity between two objects; contrast refers to difference in light levels.

What is Kohler illumination?

A technique to achieve optimal resolution and contrast in microscopy.

What is oil immersion used for?

To enhance resolution at high magnification.

What is phase-contrast microscopy?

A technique to enhance differences in refractive indices in a specimen.

What is electron microscopy?

A technique that uses electrons to achieve higher resolution than light microscopes.

What is spontaneous generation?

The incorrect idea that life can arise from non-living matter.

Who disproved spontaneous generation?

Louis Pasteur.

What are Koch's postulates?

A series of criteria to establish a causal relationship between a microbe and a disease.

What type of microscopy uses a beam of electrons?

Electron microscopy.

What is the role of pili in bacteria?

Used for adhesion and, in some cases, for DNA transfer during conjugation.

What structure is essential for bacterial motility?

Flagella.

What is binary fission?

The method by which prokaryotic cells divide.

What is the importance of the peptidoglycan layer in bacteria?

It provides structural integrity to the bacterial cell wall.

Define fermentation.

The metabolic process that converts sugars to acids, gases, or alcohol in the absence of oxygen.

What is the difference between aerobic and anaerobic respiration?

Aerobic respiration requires oxygen, while anaerobic respiration does not.

What is glycolysis?

The process of breaking down glucose to produce ATP.

What is the function of ribosomes in cells?

To synthesize proteins using mRNA as a template.

What is the central dogma of molecular biology?

DNA -> RNA -> Protein.

What is an operon?

A group of genes under the control of a single promoter.

Identify the roles of DNA polymerase.

To synthesize new DNA strands during replication.

Define horizontal gene transfer.

The transfer of genetic material between organisms other than by the usual sexual or asexual reproduction.

What is transformation in bacteria?

The process of a bacterium taking up DNA from its environment.

What are plasmids?

Extrachromosomal DNA molecules that can provide additional functions to bacteria.

Explain the significance of the lag phase in bacterial growth.

It is a period where cells adapt to new conditions before division.

What occurs during the exponential phase of bacterial growth?

Cell division rate is at its maximum and cells replicate rapidly.

What happens during the stationary phase of bacterial growth?

The rate of cell division slows down and death rate balances birth rate.

How do we estimate bacterial numbers using turbidity?

By measuring the cloudiness of a solution to determine cell density.

What is the most probable number (MPN) method?

A statistical method to estimate viable bacterial numbers by dilution series.

What is a viable count?

A method to count living bacteria by colony formation.

How is generation time defined?

The time it takes for a bacterial population to double.

What factors affect generation time in bacteria?

Nutrient availability and environmental conditions.

Why is scientific notation important in microbiology?

It simplifies the expression of large numbers of bacteria.

What is the Entner-Doudoroff pathway?

An alternative pathway to glycolysis that breaks down glucose.

What is the final electron acceptor in aerobic respiration?

Oxygen.

Describe biofilms.

Complex communities of microorganisms attached to surfaces and each other.

What are the characteristics of Archaea?

Single-celled organisms that can live in extreme environments.

What is the significance of endospores in bacteria?

They are resistant structures that allow bacteria to survive harsh conditions.

What is the difference between oxidizing and reducing reactions in metabolism?

Oxidation involves loss of electrons, while reduction involves gain of electrons.

What are chemoorganotrophs?

Organisms that obtain energy from organic compounds.

What strategy do most pathogenic bacteria employ for survival?

They often utilize multiple nutrient sources.

What is the role of extracellular enzymes in bacteria?

To break down complex molecules into simpler ones for absorption.

Define the term 'generation time'.

The time it takes for a population of bacteria to double in number.

Explain the importance of measuring bacterial abundance in research.

It helps in understanding microbial ecology and the impact of bacteria in various environments.

What are the distinct growth phases in a closed culture?

Lag phase, Log (exponential) phase, Stationary phase, Death phase.

Describe the structure and function of the Gram-negative cell wall.

It has a thin peptidoglycan layer and an outer membrane composed of lipopolysaccharides.

What technique is commonly used for isolating pure bacterial cultures?

Streak plating.

How do bacteria resist antibiotics?

Through mechanisms like efflux pumps, enzyme degradation, and altered target sites.

What is biogenesis?

The theory that living organisms arise from pre-existing life.

What is the role of antiseptics and disinfectants in medicine?

To reduce or eliminate pathogens to prevent infection.

What is the difference between a bacteriostatic and a bactericidal agent?

Bacteriostatic inhibits bacterial growth, while bactericidal kills bacteria.

Explain how microbial growth can be inhibited.

By limiting nutrient availability, changing environmental conditions, or using antimicrobial agents.

What does the term 'normal flora' refer to?

The community of microorganisms that normally inhabit the human body.