Bio- The Working Cell - Energy & Membrane Transport

A complete set of vocabulary flashcards covering energy forms, ATP metabolism, cell membrane dynamics, passive and active transport, osmosis, and transport pumps based on Chapter 5 lecture notes.

Energy

The capacity to cause change.

Kinetic Energy

The energy of motion.

Potential Energy

Stored energy that an object possesses because of its location or structure.

ATP (Adenosine Triphosphate)

A molecule consisting of adenosine attached to a tail of three phosphate groups; breaking its phosphate bonds releases energy for cellular work.

ADP (Adenosine Diphosphate)

The molecule formed when ATP loses a phosphate group and releases energy.

Fluid Mosaic Model

A model describing the cell membrane as a fluid-like, flexible structure whose individual components can move around rather than remaining rigid.

Solute

Molecules dissolved in a liquid solvent.

Solvent

The liquid or fluid that dissolves solute molecules.

Solution

A liquid mixture composed of one or more solutes dissolved in a solvent.

Concentration

The number of solute molecules in a given area per unit volume.

Equilibrium

A state in which dissolved solute molecules are spread equally throughout a solution, resulting in equal rate of movement in both directions.

Selective Permeability

The property of a cell membrane that enables it to regulate which substances pass across it.

Passive Transport

The movement of substances across a biological membrane without requiring cellular energy.

Active Transport

The movement of substances across a cell membrane that requires cellular energy ($\text{ATP}$), usually moving molecules against their concentration gradient.

Diffusion

The movement of molecules spreading out evenly into available space down their concentration gradient, from an area of higher concentration to lower concentration.

Osmosis

The diffusion of water molecules across a selectively permeable membrane until equilibrium is reached.

Hypertonic Solution

A solution with a higher concentration of solute outside the cell relative to the inside.

Hypotonic Solution

A solution with a lower concentration of solute outside the cell relative to the inside.

Isotonic Solution

A solution with an equal solute concentration on both sides of the cell membrane.

Turgor Pressure

The internal cellular pressure derived from osmotic pressure differences that keeps plant cells rigid and inflated.

Facilitated Diffusion

A type of passive transport in which polar or large molecules move across a membrane down their concentration gradient via specific transport proteins or channel proteins.

Endocytosis

An active transport process in which a cell engulfs external material by folding its cell membrane inward to form a vesicle.

Phagocytosis

A specific form of endocytosis involving the cellular engulfment of solid particles.

Pinocytosis

A specific form of endocytosis involving the cellular uptake of liquid fluid.

Exocytosis

An active transport process in which a cell secretes large particles enclosed in vesicles by fusing the vesicle membrane with the cell membrane.

Sodium-Potassium Pump ($\text{Na}^+/\text{K}^+$ Pump)

An active transport system that uses ATP hydrolysis ($\text{ATP} + \text{H}_2\text{O} \rightarrow \text{ADP} + \text{P}_i$) to pump $3\,\text{Na}^+$ ions out of the cell and $2\,\text{K}^+$ ions into the cell against their concentration gradients.