Cell Biology and Homeostasis Vocabulary

Vocabulary flashcards covering cellular structures, plasma membrane components, cellular diversity, cytoskeletal elements, and homeostasis concepts based on lecture notes.

Homeostasis

The maintenance of a relatively dynamic stable internal environment within an acceptable range.

Negative Feedback Mechanism

A homeostatic control mechanism where a change in a variable prompts a response that opposes or reverses the original stimulus, causing the variable change to decrease or disappear.

Cell Theory

The core principles stating that the cell is the basic structural and functional unit of life, all living organisms consist of one or more cells, life's continuity has a cellular basis, and organismal activity depends on individual and collective cellular actions.

Fibroblasts

Specialized human cells that produce connective tissue materials.

Erythrocytes

Mature red blood cells that transport gases, especially oxygen and carbon dioxide, and lack a nucleus and several organelles.

Epithelial Cells

Cells that form coverings and linings throughout the body.

Skeletal Muscle Cells

Cells specialized to produce voluntary body movements.

Adipocytes

Fat cells whose primary function is to store nutrients and energy.

Macrophages

Disease-fighting cells that engulf pathogens, debris, and abnormal cells.

Neurons

Specialized cells that gather information and exchange signals to help control body functions.

Plasma Membrane

A selectively permeable dynamic fluid-mosaic structure that separates the cell internal environment from the external extracellular fluid.

Phospholipid

A lipid molecule composed of a glycerol backbone, two nonpolar hydrophobic fatty acid tails, and a polar hydrophilic phosphorus-containing head.

Cholesterol

A lipid component that stabilizes the plasma membrane, helps it remain fluid-like at low temperatures, and serves as the chemical basis for all steroids in the body.

Glycolipids

Lipids attached to sugar groups that face the extracellular space.

Integral Membrane Proteins

Proteins embedded in the phospholipid bilayer containing both hydrophobic and hydrophilic regions, often spanning as transmembrane proteins.

Peripheral Membrane Proteins

Membrane proteins that are attached to the surface and are not usually embedded in the lipid bilayer.

Glycocalyx

The carbohydrate-rich area on the extracellular surface formed by branching sugar groups attached to proteins and lipids.

Diffusion

The passive movement of substances down a concentration gradient from high to low concentration.

Microfilaments

Cytoskeletal strands made of spherical protein subunits called actins.

Intermediate Filaments

Tough, insoluble cytoskeletal protein fibers constructed like ropes.

Microtubules

Cytoskeletal hollow tubes composed of spherical protein subunits called tubulins that interact with motor molecules to facilitate cell motility and organelle transport.

Centrioles

Small barrel-shaped organelles located in the centrosome consisting of a pinwheel array of nine triplets of microtubules that organize the mitotic spindle and form the bases of cilia and flagella.

Tight Junction

An impermeable membrane junction that encircles a cell to prevent passage of materials between cells.

Desmosome

An anchoring membrane junction scattered along the sides of cells to hold adjacent cells together.

Gap Junction

A nexus junction composed of connexon channels that allows chemical substances to pass directly between adjacent cells.