Lecture 2: Cells and Body Fluid Compartments

Vocabulary flashcards covering plasma membrane structure and components, body fluid compartments, and diffusion mechanisms from the lecture notes.

Plasma membrane

The cell boundary consisting of a phospholipid bilayer with embedded proteins; separates intracellular fluid (ICF) from extracellular fluid (ECF) and regulates exchange and communication with the environment.

Phospholipid

A molecule with a hydrophilic head and a hydrophobic tail; the building block of the cell membrane.

Phospholipid bilayer

Two layers of phospholipids arranged with heads facing water and tails away, forming the membrane structure.

Hydrophilic head

Water-loving portion of a phospholipid, composed of glycerol and phosphate group.

Hydrophobic tail

Water-fearing fatty acid chain portion of a phospholipid.

Extracellular Fluid (ECF)

Fluid outside the cell that surrounds it and participates in material exchange.

Intracellular Fluid (ICF)

Fluid inside the cell that contains cytoplasm and dissolved substances.

Interstitial fluid

Part of the extracellular fluid that bathes tissue cells and links plasma to cells.

Glycoprotein

Membrane protein with carbohydrate chains involved in self-recognition and signaling.

Glycolipid

Membrane lipid with carbohydrate chains that contribute to self-recognition.

Cholesterol

Sterol in the plasma membrane that modulates fluidity and stability.

Transmembrane protein

Integral membrane protein that spans the membrane; enables transport, signaling, and catalysis.

Peripheral protein

Protein attached to the membrane surface with structural or enzymatic roles.

Selectively permeable

Property of the plasma membrane that allows selective passage of substances.

Diffusion

Movement of a substance from an area of higher concentration to an area of lower concentration until equilibrium.

Simple diffusion

Diffusion directly through the lipid bilayer without the help of transport proteins.

Channel-mediated diffusion

Diffusion through protein channels forming pores for specific ions or molecules.

Facilitated diffusion

Diffusion aided by carrier or channel proteins, moving substances down their concentration gradient.

Endocytosis

Process by which cells take in material by engulfing it with the plasma membrane to form a vesicle.

Exocytosis

Process by which vesicles fuse with the plasma membrane to release contents outside the cell.