Cellular Transport, Junctions, and Energy Principles

Vocabulary flashcards generated from chapters 1 through 7 covering membrane transport, cell junctions, and thermodynamics concepts.

Osmotic pressure

The pressure that develops in a system due to osmosis.

Aquaporin

A specific channel protein that water uses to move across the cell membrane into the cell.

Carrier proteins

Specific membrane proteins that bind to molecules or ions and undergo a conformational change in shape to transport them across the membrane.

Facilitated transport

A form of transport that speeds up the passage of molecules such as glucose and amino acids down their concentration gradient without requiring ATP.

Active transport

A form of transport that uses carrier proteins and ATP energy to move molecules against their concentration gradient.

Sodium-potassium pump

An active transport pump critical for nerve and muscle cells that uses ATP to move sodium out of the cell and bring potassium into the cell.

Exocytosis

A bulk transport process where macromolecules leave the cell inside vesicles that fuse with the plasma membrane and release their contents.

Endocytosis

A bulk transport process where cells take in substances by invaginating the plasma membrane and forming vesicles.

Phagocytosis

A form of endocytosis that transports large particulate matter such as food molecules, viruses, and whole cells into the cell.

Pinocytosis

A form of endocytosis that brings liquids and small particles into the cell.

Receptor-mediated endocytosis

A specialized form of pinocytosis that uses membrane pits coated with specific receptor proteins to target specific molecules efficiently.

Extracellular matrix

A meshwork of proteins and polysaccharides located outside animal cells that provides structural support to the cell.

Adhesive junction

A type of cell junction where proteins connect the cytoskeletal filaments of adjacent cells.

Tight junction

A cell junction where proteins join the plasma membranes of adjacent cells to form an impermeable barrier.

Gap junction

A cell junction in animal cells that allows direct communication between adjacent cells.

Plasmid desmasto

Narrow channels penetrating plant cell walls containing cytoplasm strands that connect adjacent plant cells and allow exchange of water and small molecules.

Energy

The ability to do work or bring about a change.

Potential energy

Stored energy, such as chemical energy stored in chemical bonds.

Kinetic energy

The energy of motion, such as mechanical energy during movement.

First law of thermodynamics

Law stating that energy can neither be created nor destroyed, but can only be transformed from one form to another.

Second law of thermodynamics

Law stating that during energy transformation, some energy becomes unavailable to do work and is lost as heat.