Microbial Ecology and Bacterial Physiology Quiz

Definition: Study of interactions between microorganisms and their environments.
Key Concepts:
- Biogeochemical Cycles: Microbes play crucial roles in carbon, nitrogen, sulfur, and phosphorus cycles.
- Microbiomes: Communities of microorganisms in specific environments (e.g., soil, gut).
- Symbiosis: Relationships between microbes and other organisms (mutualism, commensalism, parasitism).
- Environmental Factors: pH, temperature, and nutrient availability influence microbial distribution and activity.

Cell Structure:
- Prokaryotic Cells: Lack a nucleus; contain peptidoglycan cell wall.
- Organelles: Ribosomes, plasma membrane, and sometimes flagella or pili.
Metabolism:
- Types: Aerobic (requires oxygen), anaerobic (does not require oxygen), and facultative (can switch).
- Fermentation: Anaerobic process producing ATP through substrate-level phosphorylation.
Growth and Reproduction:
- Binary Fission: Asexual reproduction resulting in two identical cells.
- Growth Phases: Lag, log (exponential), stationary, and death phase.

Definition: Study of how viruses cause disease.
Virus Structure:
- Components: Capsid (protein coat), nucleic acid (DNA or RNA), and sometimes an envelope.
Infection Mechanism:
- Attachment: Viruses bind to host cell receptors.
- Entry: Virus penetrates the host cell via endocytosis or fusion.
- Replication: Viral genome hijacks host machinery to replicate.
- Release: New viral particles exit the cell, often destroying it.
Host Response:
- Immune System: Recognition and elimination of infected cells.

Classification:
- Types: Yeasts (unicellular), molds (multicellular), and mushrooms (fruiting bodies).
Cell Structure:
- Cell Wall: Composed of chitin, distinct from bacterial peptidoglycan.
- Hyphae: Filamentous structures forming mycelium.
Reproduction:
- Asexual: Through spores, budding (yeasts).
- Sexual: Fusion of hyphae and formation of sexual spores.
Ecological Role:
- Decomposers: Breakdown organic matter, recycling nutrients.
- Symbiosis: Form mycorrhizal relationships with plants.

Definition: The ability of bacteria to resist the effects of an antibiotic.
Mechanisms of Resistance:
- Enzymatic Degradation: Production of enzymes that inactivate antibiotics (e.g., beta-lactamase).
- Altered Target Sites: Mutations in antibiotic binding sites.
- Efflux Pumps: Proteins that expel antibiotics from bacterial cells.
Causes:
- Overuse and Misuse: Prescribing antibiotics for viral infections or improper dosing.
- Agricultural Practices: Use of antibiotics in livestock feed.
Impact:
- Increased Morbidity and Mortality: More difficult to treat infections.
- Public Health Concern: Requires new strategies and research for effective treatments.

Study interactions between microorganisms and their environments.
Microbes are essential in biogeochemical cycles, particularly in carbon, nitrogen, sulfur, and phosphorus cycling.
Microbiomes refer to specific communities of microorganisms inhabiting environments like soil and the human gut.
Symbiosis includes mutualism (both benefit), commensalism (one benefits, the other is unharmed), and parasitism (one benefits at the other's expense).
Environmental factors such as pH, temperature, and nutrient availability significantly influence microbial distribution and activity.

Prokaryotic cells lack a true nucleus and have a peptidoglycan cell wall distinguishing them from eukaryotic cells.
Key organelles include ribosomes, plasma membranes, and occasionally flagella or pili for mobility and attachment.
Bacteria metabolize in various ways: aerobic (requires oxygen), anaerobic (does not require oxygen), and facultative (can adapt to both).
Fermentation is an anaerobic process generating ATP through substrate-level phosphorylation, crucial for certain bacteria.
Bacterial reproduction occurs through binary fission, creating two genetically identical cells.
Growth phases include lag (adjustment), log/exponential (rapid division), stationary (nutrient depletion), and death (cell demise).

The study of how viruses induce disease, including their structure and infection mechanisms.
Virus structure consists of a capsid (protein coat), nucleic acid (either DNA or RNA), and occasionally an envelope protecting the viral genome.
Viral infection involves attachment to specific host cell receptors, entry via endocytosis or fusion, and replication through hijacking host cellular machinery.
After replication, new viral particles are released from the host cell, often resulting in the cell's death.
The immune system plays a critical role in recognizing and eliminating infected cells, responding to viral infections.

Fungi are classified into types: yeasts (single-celled), molds (multi-cellular), and mushrooms (fruiting bodies).
Fungal cell walls are made of chitin, differing from bacterial cell walls composed of peptidoglycan.
Hyphae are filamentous structures that form mycelium, an extensive network aiding in nutrient absorption and growth.
Reproduction can be asexual, primarily through spores or budding in yeasts, or sexual, requiring the fusion of hyphae leading to the formation of sexual spores.
Fungi play a crucial ecological role as decomposers, breaking down organic matter and recycling nutrients.
Many fungi form mycorrhizal relationships with plants, aiding in nutrient uptake and fostering plant growth.

Antibiotic resistance defines the ability of bacteria to survive despite the presence of antibiotic treatments.
Resistance mechanisms include enzymatic degradation (e.g., beta-lactamase), mutations altering antibiotic binding sites, and efflux pumps that expel antibiotics from bacterial cells.
Contributing factors to resistance include the overuse and misuse of antibiotics, such as prescribing for viral infections or incorrect dosing and routine use in agriculture, especially in livestock.
Antibiotic resistance leads to increased morbidity and mortality, complicating treatment for bacterial infections.
It poses a significant public health concern, necessitating innovative strategies and research for developing effective treatments against resistant strains.