BIOG 1440 Prelim 2

108 flashcards

Autotrophs: Organisms that can synthesize their own food by acquiring non-organic compounds without requiring organic carbon sources[cite: 1].
Heterotrophs: Organisms that cannot synthesize their own food and require organic, carbon-containing compounds (such as proteins, carbohydrates, and lipids)[cite: 1].
Cation Exchange: A process where plant roots combine H2O and CO2 to produce carbonic acid, releasing H+ protons into the soil to replace and absorb bound cations like Mg2+ and K+[cite: 2].
Digestion: A physiological process where an organism breaks down macronutrients into constituent parts through nutrient breakdown and absorption[cite: 2].
Intracellular Digestion: A process where nutrients are entirely digested inside cells via phagocytosis and food vacuoles, then broken down by lysosomes[cite: 2, 3].
Extracellular Digestion: A process where organisms break down nutrients outside of cells using enzymes, acids, tissues, and organs via gastrovascular cavities or flow-through digestive tracts[cite: 3].
Mechanical Digestion: The physical breakdown of large food pieces into smaller fragments without altering their chemical structures[cite: 3].
Chemical Digestion: Chemistry-based processes that change the chemical structure of food as it undergoes decomposition into smaller molecules[cite: 3].
Enzymatic Digestion: A specialized form of chemical digestion where enzymes bind with nutrient molecule substrates to split them into smaller constituent molecules[cite: 3].
Salivary Amylases: Enzymes secreted in the oral cavity that break down large polysaccharides into small polysaccharides[cite: 4, 5].
Pepsinogen: An inactive zymogen precursor secreted by chief cells in the stomach that is converted into active pepsin by hydrochloric acid (HCl)[cite: 5].
Pepsin: An active stomach enzyme that enzymatically breaks down proteins into small polypeptides via a positive feedback loop[cite: 4, 5].
Parietal Cells: Stomach cells that secrete hydrochloric acid (HCl)[cite: 5].
Chief Cells: Stomach cells that secrete pepsinogen[cite: 5].
Pancreatic Amylases: Enzymes secreted by the pancreas into the duodenum that break down small polysaccharides into disaccharides[cite: 4, 5].
Trypsin & Chymotrypsin: Protease enzymes secreted by the pancreas that break down small polypeptides into smaller polypeptides[cite: 4, 5].
Pancreatic Carboxypeptidase: An enzyme that breaks down smaller polypeptides into small peptides[cite: 4, 5].
Pancreatic Nucleases: Enzymes that break down DNA and RNA into nucleotides[cite: 4, 5].
Pancreatic Lipases: Enzymes that break down triglyceride fats into glycerol, fatty acids, and monoglycerides[cite: 4, 5].
Disaccharidases: Intestinal brush border enzymes that break down disaccharides into monosaccharides[cite: 4, 5].
Dipeptidases, Carboxypeptidases, & Aminopeptidases: Intestinal enzymes that break down small peptides into amino acids[cite: 4, 5].
Nucleotidases: Enzymes that break down nucleotides into nucleosides[cite: 4, 5].
Nucleosidases & Phosphatases: Enzymes that break down nucleosides into nitrogenous bases, sugars, and phosphates[cite: 4, 5].
Zymogen: An inactive precursor of an enzyme that requires a biochemical change to transform into an active enzyme[cite: 5].
Duodenum: The initial section of the small intestine where the vast majority of digestive enzyme breakdowns occur[cite: 5, 6].
Secretin: An enzyme/hormone secreted by the duodenum in response to acidic chyme, triggering pancreatic bicarbonate release[cite: 6].
Hepatic Portal Vein: A specialized vein that transports absorbed non-lipid nutrients and water directly to the liver for processing[cite: 6, 7].
Symbiosis: A close, long-term interaction where two different species interact and possibly co-evolve[cite: 7].
Mutualism: A symbiotic relationship where both interacting species benefit[cite: 7, 10].
Commensalism: A symbiotic relationship where one species benefits while the other remains unaffected[cite: 7].
Parasitism: A symbiotic relationship where one species benefits while the other is harmed[cite: 7, 10].
Endosymbionts: Microorganisms that reside within the individual cells of an organism host[cite: 8].
Microbiota: The community of microorganisms associated with an organism host living on exterior surfaces or within body cavities rather than inside cells[cite: 8].
Endosymbiotic Theory: The theory stating that membrane-bound eukaryotic organelles (mitochondria and chloroplasts) originated from prokaryotic endosymbionts[cite: 8].
Plant-Growth-Promoting Rhizobacteria (PGPR): Beneficial root bacteria that produce antibiotics, trap nutrients, and solubilize minerals for plants in exchange for sugars[cite: 9, 10].
Arbuscular Mycorrhizal Fungi (AMF): Beneficial fungi that transfer soil water, phosphorus, and nitrogen to plant roots in exchange for photosynthetic carbon and sugars[cite: 9, 10].
The Nitrogen Cycle: The cyclic conversion of atmospheric nitrogen gas into ammonia, ammonium, nitrites, and nitrates by various soil bacteria[cite: 8, 9].
Rhizobia: Nitrogen-fixing bacteria that form endosymbiotic relationships with legume roots inside root nodules[cite: 9, 10].
Flavonoids: Chemical signals released by legume roots into the soil to attract compatible rhizobia[cite: 10].
Nod Factors: Bacterial signaling molecules released after binding with flavonoids that trigger legume root growth and nodule formation[cite: 10].
Gut Microbiota: The complex community of microbes residing primarily in the colon that aids in digestion, vitamin synthesis, immunity, and metabolism[cite: 11].
Short-Chain Fatty Acids (SCFAs): Fatty acids produced by gut microbial fermentation of dietary fiber in the colon[cite: 11].
Gut-Brain Axis: The bidirectional communication network linking the gut microbiome with the nervous and endocrine systems[cite: 11].
Dysbiosis: A medical term for a microbial imbalance in the human body that leads to disease and impaired homeostasis[cite: 12].
Diffusion: A passive transport process with a rate that scales inverse quadratically with distance, making it insufficient for rapid long-distance transport in large organisms[cite: 12, 13].
Bulk Flow: The movement of fluid along a pressure gradient through a vascular plumbing system, enabling rapid long-distance transport[cite: 13].
Xylem: A plant vascular system composed of dead cells (tracheids and vessel elements) that transports water and minerals upward from roots via negative pressure and transpiration[cite: 13, 14, 15].
Phloem: A plant vascular system made of living sieve elements that translocates photosynthetic sugars bidirectionally from source tissues to sink tissues[cite: 14, 15].
Translocation: The active or passive loading, hydrostatic pressure-driven movement, and unloading of sugars through the phloem[cite: 14].
Open Circulatory System: A circulatory system where hemolymph is pumped by a heart into open sinuses and cavities to bathe tissues directly[cite: 15].
Closed Circulatory System: A circulatory system where blood is confined entirely to continuous interconnected vessels driven by a muscular heart[cite: 15, 16].
Pulmonary Circuit: The vertebrate circulatory pathway that pumps deoxygenated blood to the lungs to acquire oxygen and release carbon dioxide[cite: 15, 16].
Systemic Circuit: The vertebrate circulatory pathway that pumps oxygenated blood from the heart to the rest of the body[cite: 16].
Arteries: Blood vessels that carry blood flow outward from the heart to the periphery[cite: 16].
Veins: Blood vessels that return blood from the periphery back to the heart[cite: 16].
Capillaries: Microscopic junction vessels connecting arteries and veins where tissue perfusion and material exchange occur[cite: 16, 17].
Atrium: A thin-walled heart chamber that primes the pump[cite: 16].
Ventricle: A muscular heart chamber that acts as the primary pump[cite: 16].
Continuity Equation: The fluid dynamics principle stating that total net flow remains constant throughout an incompressible fluid system. Q1 = Q2, or A1V1 = A2V2. [cite: 17].
Poiseuille's Law: The physical law governing fluid flow rate through a tube based on pressure differences, radius, length, and fluid viscosity. Fluid flow rate is inversely proportional to the radius. [cite: 17].
Vasoconstriction: The contraction of vascular smooth muscle in arterioles that decreases vessel radius, increases resistance, and lowers local blood flow[cite: 18].
Vasodilation: The relaxation of vascular smooth muscle in arterioles that increases vessel radius, decreases resistance, and raises local blood flow[cite: 18].
Precapillary Sphincters: Microscopic muscle cells at the arteriole-capillary junction that regulate microcirculatory blood flow based on tissue metabolic activity[cite: 18].
Systole: The phase of ventricular contraction that expulses blood into the aorta at high pressure[cite: 19].
Diastole: The phase of ventricular relaxation and refilling where elastic recoil of vessels maintains baseline blood pressure[cite: 19].
Hypertension: A chronic cardiovascular condition where blood pressure exceeds the healthy upper limit of 120/80 mmHg[cite: 20].
Hydrostatic Pressure: The physical force exerted by blood pressure against vessel walls[cite: 20].
Osmotic Pressure: The pressure generated by an osmotic concentration gradient across a membrane[cite: 20].
Oncotic Pressure: The specific osmotic pressure exerted by blood plasma proteins (albumin) that remains constant along the capillary[cite: 20].
Atrioventricular (AV) Valves: Heart valves (tricuspid and mitral) connecting the atria to the ventricles to prevent backflow during systole[cite: 22].
Semilunar (SL) Valves: Heart valves (pulmonary and aortic) connecting the ventricles to major arteries to prevent backflow during diastole[cite: 22].
The Cardiac Cycle: The complete sequence of alternating contraction and relaxation phases in heart chambers during a single heartbeat[cite: 22].
Sinoatrial (SA) Node: A cluster of specialized pacemaker cells in the right atrium that generates the baseline electrical rhythm of the heart[cite: 23, 24].
Atrioventricular (AV) Node: A secondary node in the lower right atrium that receives and relays the electrical impulse toward the ventricles[cite: 23, 24].
Bundle of His: Heart muscle fibers located in the interventricular septum that split the electrical signal into right and left bundle branches[cite: 23, 24].
Purkinje Fibers: Specialized muscle fibers that spread the electrical action potential rapidly throughout the ventricular walls[cite: 23, 24].
Myogenic Rhythm: The intrinsic, self-generating contraction rhythm of heart muscle fibers coordinated by the SA node[cite: 24].
Cardiomyocytes: Striated cardiac muscle cells responsible for heart wall contractions[cite: 25].
Intercalated Discs: Porous junctions connecting adjacent cardiomyocytes that allow rapid electrical coupling and coordinated wave contractions[cite: 25].
Norepinephrine: A sympathetic neurotransmitter/hormone that binds to beta-1 receptors to increase calcium influx and speed up heart rate during fight-or-flight[cite: 25].
Acetylcholine: A parasympathetic neurotransmitter/hormone released by vagus nerves that hyperpolarizes cardiomyocytes to slow down heart rate[cite: 25].
Extracellular Fluid (ECF): Body fluid outside of cells comprising blood plasma and interstitial fluid that acts as a transport vehicle and maintains cell structure[cite: 25, 26].
Intracellular Fluid: Fluid located inside cells (cytoplasm)[cite: 26].
Interstitial Fluid: Extracellular fluid that surrounds tissue cells and acts as a transport intermediate[cite: 26].
Blood Plasma: The fluid component of blood circulating within vascular vessels[cite: 26].
Osmoconformers: Organisms whose internal cellular osmotic pressure matches directly with ambient environmental osmolarity[cite: 27].
Osmoregulators: Organisms that expend metabolic energy to actively regulate and maintain stable internal ECF volume, ion concentration, and osmotic pressure[cite: 27, 28].
Hypovolemia (Isotonic Dehydration): A fluid deficit characterized by a drop in blood plasma volume, triggering extracellular thirst via baroreceptors[cite: 29, 30].
Hypernatremia (Hypertonic Dehydration): A fluid deficit caused by excessively high ECF electrolyte concentration, triggering intracellular thirst via hypothalamic osmoreceptors[cite: 29, 30].
Osmoreceptors: Hypothalamic sensory receptors that detect changes in ECF osmolarity and trigger osmotic thirst[cite: 30].
Baroreceptors: Arterial pressure sensors that detect changes in blood pressure/volume and trigger hypovolemic thirst[cite: 30].
Ammonia: The most basic, highly toxic form of nitrogenous waste excreted primarily by aquatic organisms requiring large water volumes[cite: 30, 31].
Urea: A moderately toxic form of nitrogenous waste cyclically synthesized and excreted by mammals and some bony fishes with water[cite: 30, 31].
Uric Acid: A low-toxicity nitrogenous waste synthesized at high metabolic energy cost and excreted mostly as a semi-solid paste by birds, reptiles, and insects[cite: 31].
Filtration: The initial excretory step where high hydrostatic pressure drives water and small solutes from blood into a primary filtrate tube[cite: 31].
Reabsorption: The selective movement of water, ions, and nutrients out of the filtrate tube back into blood capillaries[cite: 31].
Secretion: The active transport of toxins and waste products from blood capillaries back into the filtrate tube[cite: 31].
Nephron: The functional microscopic unit of the kidney responsible for urine formation through filtration, reabsorption, and secretion[cite: 31, 32].
Bowman's Capsule: The cup-shaped upper end of the nephron that collects the primary urine filtrate generated by the glomerulus[cite: 31, 32, 33].
Glomerulus: A dense capillary network enclosed by Bowman's capsule that performs blood filtration driven by net hydrostatic pressure[cite: 32, 33].
Proximal Convoluted Tubule: The initial coiled nephron segment responsible for isotonic reabsorption of nutrients, salts, and water, along with pH regulation[cite: 31, 32, 34].
Loop of Henle: The hairpin nephron loop consisting of a descending and ascending limb that utilizes countercurrent multiplication to concentrate urine[cite: 31, 32, 34, 35].
Distal Convoluted Tubule: A nephron segment that performs hormonally regulated reabsorption of salts and ions to fine-tune fluid balance and pH[cite: 31, 32, 34, 35].
Collecting Duct: The final tubular duct of the nephron that adjusts final urine concentration under the control of antidiuretic hormone (ADH)[cite: 31, 32, 34, 36].
Vasa Recta: Blood capillary vessels running alongside the loop of Henle that maintain the medullary osmotic gradient[cite: 32].
Aldosterone: A mineralocorticoid hormone that stimulates sodium and water reabsorption in the distal tubule and collecting duct, reducing urine volume[cite: 33, 35].
Antidiuretic Hormone (ADH/Vasopressin): A posterior pituitary hormone that inserts aquaporins into the collecting duct to increase water reabsorption when blood osmolarity is high[cite: 33, 36].
Countercurrent Multiplication: The repeating active transport and fluid movement mechanism in the Loop of Henle that establishes a steep vertical osmotic gradient in the kidney medulla[cite: 35, 37].