Cellular Form and Function (Dr. Olivey, P261)

Vocabulary flashcards covering key concepts from the lecture notes on cellular form and function.

Cell theory

The idea that cells are the building blocks of all plants and animals; produced by division of preexisting cells; the smallest units that perform all vital physiological functions; each cell maintains homeostasis at the cellular level; higher-level homeostasis results from the coordinated action of many cells.

Cellular homeostasis

Maintenance of stable internal conditions at the cellular level in response to environmental changes.

Preexisting cells

Cells divide to produce new cells; new cells arise from preexisting cells.

Somatic cells

Body cells excluding germ cells; form most tissues and organs.

Germ cells

Sex cells (gametes: sperm and oocytes) involved in reproduction.

100 μm average diameter

Approximate average diameter of a cell; actual cells vary in size and shape.

Motor neuron

A neuron whose cell body is in the brain or spinal cord and that innervates muscles (e.g., to the foot).

Squamous

Flat, scale-like cell shape.

Cuboidal

Cube-shaped cell.

Columnar

Tall, column-like cell.

Polygonal

Irregular, multi-sided cell shape.

Stellate

Star-shaped cell.

Spheroidal

Spherical cell.

Discoidal

Disc-shaped cell.

Fusiform

Spindle-shaped cell.

Fibrous

Thread-like elongated cell shape.

Basic unit of life

The cell is the fundamental unit of life in all organisms.

Protection and support (cell function)

Cells protect and support tissues by producing and secreting molecules.

Movement (cell function)

Movement occurs due to specialized proteins and the cell’s cytoskeleton.

Communication (cell function)

Cells produce and receive electrical and chemical signals.

Metabolism and energy release

Cellular processes that extract and use energy from nutrients.

DNA

The genetic material contained in cells.

Cytology

The study of the structure and function of cells.

Cytosol

Intracellular fluid inside the cell.

Organelles

Specialized structures within the cytoplasm that perform specific functions.

Cytoskeleton

Network of protein filaments that give the cell its shape and structural support.

Nucleus

Membrane-bound organelle containing the cell’s DNA; control center of the cell.

Nucleolus

Nuclear substructure where ribosomal RNA synthesis occurs.

Nuclear envelope

Double membrane surrounding the nucleus; separates nucleus from cytoplasm.

Mitochondrion

Organelle that produces ATP via cellular respiration.

Rough endoplasmic reticulum

ER with ribosomes; site of protein synthesis destined for secretion or membranes.

Smooth endoplasmic reticulum

ER without ribosomes; involved in lipid synthesis and detoxification.

Ribosome

Organelle that synthesizes proteins; can be free in cytosol or attached to rough ER.

Golgi complex

Organelle that packages, modifies, and ships proteins and lipids to their destinations.

Lysosome

Organelle containing digestive enzymes for breakdown of waste materials.

Plasma membrane

The cell membrane; outer boundary that separates the intracellular and extracellular environments.

Extracellular fluid (ECF)

Fluid outside cells, including interstitial fluid.

Intracellular fluid (cytosol)

Fluid inside cells; site of many metabolic processes.

Phospholipid bilayer

Two-layered membrane structure formed by phospholipids; fundamental component of cell membranes.

Selective permeability

Membrane property that allows some substances to cross while restricting others.

Cholesterol (membrane)

Sterol in the membrane that modulates fluidity and stability.

Membrane proteins

Proteins associated with the cell membrane; functions include receptors, transporters, channels, enzymes, and anchors.

Integral (transmembrane) proteins

Proteins that span the membrane and have hydrophilic and hydrophobic regions.

Peripheral proteins

Proteins attached to the membrane surface; not embedded in the lipid bilayer.

Glycocalyx

Carbohydrate-rich coating on the cell surface composed of proteoglycans, glycolipids, and glycoproteins.

Microvilli

Fingerlike surface projections that increase cell surface area; common in absorptive cells.

Brush border

Dense array of microvilli forming a highly folded, absorptive surface.

Diffusion

Net movement of solutes from high to low concentration due to random molecular motion.

Concentration gradient

Difference in solute concentration across space that drives diffusion.

Osmosis

Diffusion of water across a semipermeable membrane in response to solute differences.

Osmotic pressure

Forces exerted by solute concentrations that drive water movement into solutions.

Tonicity

Effect of external solutions on cell volume (isotonic, hypotonic, hypertonic).