Anatomy and Physiology of Microorganisms

Cell Types:
- Prokaryotic: Bacteria and Archaea; lack a nucleus and membrane-bound organelles.
- Eukaryotic: Fungi, Protozoa, and Algae; contain a nucleus and organelles.
Basic Components:
- Cell Membrane: Selectively permeable barrier.
- Cell Wall: Provides structure (peptidoglycan in bacteria).
- Cytoplasm: Gel-like fluid where cellular processes occur.
- Ribosomes: Site of protein synthesis.
- Genetic Material: DNA in prokaryotes is circular; eukaryotes have linear DNA in the nucleus.

Metabolism:
- Catabolism: Breakdown of substances to generate energy.
- Anabolism: Synthesis of cellular components for growth.
Energy Sources:
- Autotrophs: Use inorganic substances (e.g., photosynthesis in cyanobacteria).
- Heterotrophs: Require organic compounds (e.g., humans consuming food).
Reproduction:
- Asexual: Binary fission (most bacteria).
- Sexual: Conjugation, transformation, or transduction.

Bacteria:
- Shapes: Cocci (spherical), Bacilli (rod-shaped), Spirilla (spiral).
- Gram Staining: Determines bacterial cell wall composition (Gram-positive/negative).
Fungi:
- Yeasts: Unicellular; reproduce via budding.
- Molds: Multicellular; grow as hyphae and produce spores.
Protozoa:
- Diverse group; can be motile (flagella, cilia, or pseudopodia).
- Some are pathogenic (e.g., Plasmodium causes malaria).
Viruses:
- Acellular; consist of RNA or DNA core surrounded by a protein coat.
- Require a host cell for replication.

Medical: Pathogens cause diseases; understanding leads to treatments and vaccines.
Environmental: Microorganisms play crucial roles in ecosystems (decomposition, nutrient cycling).
Industrial: Used in biotechnology (fermentation, production of antibiotics).

Innate Immunity: Non-specific defenses (skin, inflammation, phagocytes).
Adaptive Immunity: Specific response (B cells produce antibodies, T cells kill infected cells).

Microorganisms can be beneficial or harmful.
Understanding their physiology and anatomy is crucial for medical and environmental science.
Host defenses and microbial pathogenicity are fundamental in infectious disease research.

Prokaryotic cells lack a nucleus and membrane-bound organelles, found in bacteria and archaea
Eukaryotic cells have a nucleus and membrane-bound organelles, found in fungi, protozoa, and algae
Cell membrane acts as a selectively permeable barrier
Cell wall provides structural support, composed of peptidoglycan in bacteria
Cytoplasm is a gel-like fluid where cellular processes occur
Ribosomes are responsible for protein synthesis
Genetic material in prokaryotes is circular DNA, while eukaryotes have linear DNA within the nucleus

Metabolism encompasses catabolism (breaking down substances for energy) and anabolism (building cellular components)
Autotrophs obtain energy from inorganic substances, like cyanobacteria using photosynthesis
Heterotrophs obtain energy from organic compounds, like humans consuming food
Asexual reproduction is common in bacteria, primarily through binary fission
Sexual reproduction in microorganisms can occur through conjugation, transformation, or transduction

Bacteria are classified based on their shape (cocci, bacilli, spirilla) and Gram staining (positive or negative based on cell wall composition)
Fungi include yeasts, which are unicellular and reproduce by budding, and molds, which are multicellular, grow as hyphae, and produce spores
Protozoa are diverse, motile organisms with various methods of movement (flagella, cilia, or pseudopodia); some are pathogenic, like Plasmodium which causes malaria
Viruses are acellular entities consisting of an RNA or DNA core surrounded by a protein coat; they require a host cell for replication

Medical microbiology focuses on understanding pathogens and developing treatments and vaccines
Environmental microbiology explores the critical roles microorganisms play in ecosystems, including decomposition and nutrient cycling
Industrial microbiology utilizes microorganisms in biotechnology for processes like fermentation and antibiotic production

Mutualism benefits both the host and microbes, such as the gut microbiota
Commensalism provides benefits for microbes without harming the host
Pathogenicity refers to microbes causing disease by disrupting host functions

Innate immunity provides non-specific defenses including skin, inflammation, and phagocytes
Adaptive immunity involves a specific response where B cells produce antibodies and T cells target infected cells

Microorganisms can have both beneficial and harmful effects
Understanding their physiology and anatomy is crucial for advances in medical and environmental science
The interplay between host defenses and microbial pathogenicity is central to infectious disease research