Video Notes: Cellular Biology and Physiology - Key Terms (Vocabulary)

A set of vocabulary flashcards covering core concepts from the lecture notes, suitable for exam preparation.

Anabolism

Synthesis of complex molecules from simpler ones; energy stored in the process (constructive metabolism).

Catabolism

Chemical reactions that break down macromolecules to release energy for cellular use (energy-yielding metabolism).

ATP

Adenosine triphosphate, the main energy currency of the cell used for work and biosynthesis.

Glycolysis

Cytoplasmic pathway that converts glucose to pyruvate, producing ATP and NADH.

Pyruvate

End product of glycolysis that is transported into mitochondria to form acetyl-CoA.

Acetyl-CoA

A two-carbon molecule that enters the citric acid cycle to generate energy precursors.

Citric acid cycle (Krebs, TCA)

Mitochondrial cycle that oxidizes acetyl-CoA, generating energy carriers (NADH, FADH2) and CO2.

Oxidative phosphorylation

Final ATP-producing step where electron transport creates a proton gradient that drives ATP synthesis.

Electron transport chain

Protein complexes in the inner mitochondrial membrane that transfer electrons and pump protons.

Diffusion

Passive movement of molecules down their concentration gradient without energy use.

Osmosis

Diffusion of water across a semipermeable membrane to balance solute concentrations.

Filtration

Separation of suspended particles through a filter or membrane driven by pressure.

Passive transport

Movement of substances across membranes without energy input (diffusion, osmosis, filtration).

Active transport

Energy-dependent movement of substances against their gradient, often via pumps.

Uniport

Transport of a single solute in one direction across a membrane.

Symport

Cotransport of two solutes in the same direction across a membrane.

Antiport

Cotransport of two solutes in opposite directions across a membrane.

Endocytosis

Cellular uptake of extracellular material via vesicle formation.

Pinocytosis

Endocytosis of fluids and dissolved substances (cell drinking).

Phagocytosis

Endocytosis of large particles or organisms, digested by lysosomal enzymes.

Exocytosis

Release of intracellular contents to the extracellular space via vesicle fusion.

Na+/K+ ATPase

Membrane pump that exchanges 3 Na+ out for 2 K+ in; uses ATP; maintains resting potential.

Solute

Dissolved substance in a solvent.

Electrolyte

Dissociates into ions (e.g., Na+, K+, Cl−) and conducts electrical current.

Nonelectrolyte

Substances (e.g., glucose) that do not dissociate into ions in solution.

Osmolality

Concentration of solute particles per kilogram of solvent; drives osmosis.

Tonicity

Relation of solution solute concentration to cell; isotonic, hypertonic, hypotonic.

RAAS (Renin-Angiotensin-Aldosterone System)

Hormonal system regulating blood pressure, Na+, and water balance.

Renin

Kidney enzyme activated by low BP/volume; converts angiotensinogen to angiotensin I.

Angiotensin I

Precursor to angiotensin II formed by renin; converted by ACE.

ACE (Angiotensin-Converting Enzyme)

Converts angiotensin I to angiotensin II; primarily in lungs.

Angiotensin II

Potent vasoconstrictor that raises BP and stimulates aldosterone release.

Aldosterone

Adrenal hormone increasing Na+ reabsorption and K+ secretion in kidneys.

Natriuretic peptides (ANP, BNP)

Hormones that promote Na+ excretion and reduce extracellular fluid volume.

ADH (vasopressin)

Hormone increasing renal water reabsorption; triggered by high osmolality or low volume.

Osmoreceptors

Receptors that detect plasma osmolality and regulate thirst/ADH release.

Baroreceptors

Pressure-sensing receptors that influence ADH release via blood volume changes.

Isotonic fluid

Fluid with proportional changes in water and electrolytes similar to cells.

Hypertonic

Solution with higher solute concentration; causes water to leave cells.

Hypotonic

Solution with lower solute concentration; causes water to enter cells.

Edema

Excess fluid accumulation in interstitial spaces due to altered Starling forces.

Starling forces

Hydrostatic and oncotic forces governing fluid movement across capillary walls.

Hydrostatic pressure

Pressure pushing fluid out of capillaries into interstitial space.

Oncotic (colloid osmotic) pressure

Pressure pulling water into capillaries via plasma proteins.

Sodium (Na+)

Major extracellular cation; governs osmotic balance and neuromuscular function.

Potassium (K+)

Major intracellular cation; essential for action potentials and muscle function.

Chloride (Cl−)

Major extracellular anion; helps maintain electrical neutrality and acid-base balance.

Phosphate (PO4^3−)

Intracellular anion involved in energy bonds and buffering; largely in bone.

Calcium (Ca2+)

Essential for bones, clotting, hormone secretion, and muscle contraction; tightly regulated.

Magnesium (Mg2+)

Intracellular cation; cofactor for enzymes and regulator of cardiac excitability.

Parathyroid hormone (PTH)

Increases serum Ca2+ by actions on bone and kidneys; activates vitamin D.

Vitamin D

Fat-soluble vitamin that increases Ca2+ absorption from the GI tract.

Calcitonin

Hormone that lowers serum Ca2+; opposes PTH effects.

Hypocalcemia

Ca2+ below normal; increases neuromuscular excitability; risk of tetany and seizures.

Hypercalcemia

Ca2+ above normal; can cause weakness, stones, constipation, and cardiac effects.

Hyperphosphatemia

Elevated phosphate; often accompanies hypocalcemia; may cause soft tissue calcification.

Hypophosphatemia

Low phosphate; leads to osteomalacia, weakness, and bleeding disorders.

Sodium-phosphate balance

Integrated regulation of Na+ and phosphate by hormones and kidneys.

Mitochondrial DNA 4977 deletion

Common mtDNA deletion associated with aging and degenerative diseases.

Necrosis

Irreversible cell death with membrane disruption and inflammation.

Coagulative necrosis

Ischemic injury typical in kidney, heart, and adrenal glands; protein denaturation.

Liquefactive necrosis

Necrosis where tissue becomes liquified (e.g., brain) due to hydrolytic enzymes.

Caseous necrosis

TB-associated necrosis with cheese-like appearance, mixed coagulative/liquefactive.

Fat necrosis

Destruction of fat tissue (e.g., pancreas) with saponification of lipids.

Gangrene

Tissue necrosis; dry (coagulative), wet (liquefactive), or gas (clostridial infection).

Apoptosis

Programmed, orderly cell death without broad inflammation.

Autophagy

Self-digestion process where cells recycle components; a form of programmed death.

Ischemia

Inadequate blood supply leading to hypoxia and potential cell injury.

Free radicals/Reactive oxygen species (ROS)

Highly reactive molecules causing oxidative damage to lipids, proteins, and DNA.

Oxidative stress

Damage from excess ROS when antioxidants are insufficient.

Mitosis

Cell division producing two genetically identical daughter cells.

Interphase (G1, S, G2)

Cell cycle phases before mitosis; G1 grows, S duplicates DNA, G2 prep for division.

Prophase to Telophase

Mitosis stages: prophase, prometaphase, metaphase, anaphase, telophase.

Cytokinesis

division of cytoplasm, yielding two separate daughter cells.

Epithelial tissue

Covers surfaces and linings; can be simple or stratified; shapes include squamous, cuboidal, columnar.

Connective tissue

Supports and connects tissues; includes loose, adipose, bone, cartilage.

Muscle tissue

Three types: smooth, cardiac, and skeletal; responsible for movement and force.

Neural tissue

Nervous tissue containing neurons and glia; facilitates rapid electrical signaling.

Mitosis vs Meiosis

Mitosis creates two identical diploid cells; meiosis forms haploid gametes.

Interphase and M phase

Interphase prepares the cell; M phase includes mitosis and cytokinesis.

Neural signaling components

Neurons with cell bodies, axons, dendrites, synapses, and neurotransmitters.