micro 4000 mt 1 SP26

sorry for the ! it was the only way I could import them and separate terms and definitions

Prokaryotic vs. Eukaryotic Cells

Prokaryotes (Bacteria, Archaea) lack a true nucleus and membrane-bound organelles, and are generally smaller, while Eukaryotes (Protozoa, Algae, Fungi, Helminths) have a membrane-bound nucleus and organelles!

Bacterial Morphology

The shapes of bacterial cells, including Cocci (spheres), Bacilli (rods), Vibrio (comma-shaped), Spirilla (rigid spirals), and Spirochetes (flexible corkscrews)!

Bacterial Arrangements

How bacteria group together after division, such as Diplo- (pairs), Strepto- (chains), Staphylo- (clusters), Tetrads (groups of 4), and Sarcinae (cubes of 8)!

Peptidoglycan (PG)

A mesh-like structure in bacterial cell walls made of parallel glycan chains (NAG and NAM disaccharides) cross-linked by short peptides!

Gram-Positive Bacteria

Bacteria with a thick cell wall (many peptidoglycan layers) and teichoic acids that stain purple in the Gram stain!

Gram-Negative Bacteria

Bacteria with a thin cell wall (few peptidoglycan layers) and an outer membrane containing Lipopolysaccharides (LPS) and porins that stain pink/red!

Periplasm

The space between the inner cell membrane and the outer membrane in Gram-negative bacteria where extracellular enzymes are often located!

Lipopolysaccharide (LPS)

A component of the Gram-negative outer membrane consisting of the O-polysaccharide (antigen) and Lipid A (endotoxin)!

Rebecca Lancefield

A scientist who developed a serological system (Lancefield Grouping) to classify Streptococci based on the carbohydrate composition of their cell walls!

Medical Relevance of Cell Envelope

It contains targets for antibiotics (e.g., Penicillin targets peptide bridges) and virulence factors like Lipid A (endotoxin) which triggers inflammation,!

Mycobacteria

Bacteria related to Gram-positives that have waxy mycolic acids in their cell walls, requiring Acid-Fast staining for identification!

Mycoplasma

Bacteria that completely lack a cell wall, are pleomorphic, and rely on sterols in their membrane for strength!

Passive Transport

The movement of nutrients from high to low concentration without energy input, including simple diffusion, facilitated diffusion, and osmosis,!

Active Transport

The movement of nutrients from low to high concentration requiring energy, such as ATP (Primary/ABC transporters), ion gradients (Coupled transport), or PEP (Group translocation),!

Group Translocation

A type of active transport where the molecule is chemically modified (phosphorylated) as it enters the cell, using energy from a high-energy metabolite like PEP!

Bacterial Secretion

The use of ATP-powered complex systems (Type I-VI) to expel proteins, toxins, and other large molecules from the cell, distinct from eukaryotic exocytosis!

Glycocalyx

A sugar shell layer outside the cell wall that can form a capsule (organized/firm for protection) or a slime layer (loose for attachment)!

S-Layer

An external protein lattice found in some bacteria and archaea that provides structural strength and helps avoid the host immune system!

Fimbriae vs. Pili

Fimbriae are short and numerous for attachment to surfaces, while Pili are longer and fewer, used for conjugation (DNA transfer) or twitching motility!

Bacterial Flagella

Long, propeller-like structures made of flagellin protein that rotate to provide motility, powered by the Proton Motive Force (PMF)!

Eukaryotic Flagella

Whip-like structures made of microtubules that slide back and forth using ATP, distinct from the rotating bacterial flagella!

Axial Filament (Endoflagella)

Internal flagella located in the periplasm of Spirochetes that wrap around the cell to create a corkscrew motility!

Nucleoid

The region in a prokaryotic cell containing the chromosome and DNA-binding proteins, lacking a membrane!

Plasmids

Small, circular, extrachromosomal DNA molecules that replicate independently and carry non-essential genes (e.g., antibiotic resistance)!

Ribosomes (70S vs. 80S)

The sites of protein synthesis

Endosymbiotic Theory

The theory that mitochondria and chloroplasts evolved from bacteria engulfed by a larger cell, supported by their 70S ribosomes and circular DNA!

Catabolism

The breakdown of molecules to release energy!

Anabolism

The use of energy to build complex molecules (biosynthesis)!

ATP Production Methods

Substrate-Level Phosphorylation (direct transfer of phosphate), Oxidative Phosphorylation (using PMF from respiration), and Photophosphorylation (using PMF from light energy),!

Redox Reactions

Reactions where one molecule loses electrons (Oxidation) and another gains electrons (Reduction), often involving the transfer of Hydrogen ions!

Electron Carriers

Molecules like NADH and FADH2 that shuttle high-energy electrons to the Electron Transport Chain!

Enzymes

Biological catalysts (proteins) that speed up reactions by lowering activation energy and are regulated by feedback inhibition!

Glycolysis (EMP Pathway)

The oxidation of glucose to 2 pyruvate, yielding a net of 2 ATP and 2 NADH!

Preparatory Step

The conversion of 2 Pyruvate to 2 Acetyl-CoA, releasing 2 CO2 and reducing 2 NAD+ to 2 NADH!

TCA (Krebs) Cycle

A cycle that oxidizes Acetyl-CoA to CO2, producing 2 ATP, 6 NADH, and 2 FADH2 per glucose molecule!

Electron Transport Chain (ETC)

A series of membrane complexes that transfer electrons from donors (NADH) to acceptors (like O2), pumping protons to create a Proton Motive Force!

Proton Motive Force (PMF)

A chemiosmotic gradient of H+ ions across the membrane used by ATP Synthase to make ATP!

Aerobic Respiration

Respiration where Oxygen (O2) is the final electron acceptor!

Anaerobic Respiration

Respiration where an inorganic molecule other than oxygen (e.g., Nitrate, Sulfate) is the final electron acceptor!

Fermentation

The partial catabolism of glucose without an ETC or Oxygen, using Pyruvate as the final electron acceptor to regenerate NAD+!

Lactic Acid Fermentation

Pyruvate is reduced to lactic acid (e.g., in yogurt bacteria or muscles)!

Alcohol Fermentation

Pyruvate is converted to acetaldehyde and then reduced to ethanol, releasing CO2 (e.g., in yeast)!

Chemolithotrophs

"Rock eaters" that harvest energy from the oxidation of inorganic chemicals (like H2, H2S, Fe2+)!

Phototrophs

Organisms that harvest energy from light using chlorophylls or bacteriochlorophylls!

Oxygenic Phototrophy

Phototrophy that uses water as an electron source and releases Oxygen (e.g., Cyanobacteria, Algae, Plants)!

Anoxygenic Phototrophy

Phototrophy that uses sources like H2S instead of water and does not release Oxygen (e.g., Purple and Green bacteria)!

Autotrophs

Organisms that fix inorganic CO2 into organic sugar, often via the Calvin Cycle and the enzyme Rubisco!

Microbiology

The study of microscopic organisms including bacteria, archaea, viruses, fungi, protozoa, and algae!

Germ Theory of Disease

The concept that specific diseases are caused by specific microscopic germs!

Koch's Postulates

A set of criteria developed by Robert Koch to scientifically link a specific pathogen to a specific disease!

Louis Pasteur

A scientist who disproved spontaneous generation with S-neck flasks, developed pasteurization, and created vaccines using attenuated strains,!

Edward Jenner

The pioneer of vaccination who used cowpox to protect against smallpox!

Binomial Nomenclature

The naming system using Genus and species (e.g., Escherichia coli)!

Three Domains of Life

Bacteria, Archaea, and Eukarya, a classification proposed by Carl Woese based on ribosomal RNA!

Microbiota

The community of microbes in/on the human body that aids digestion, immune development, and pathogen resistance!