Unit 5

Transport proteins

Proteins that may or may not use ATP to move chemicals in or out of the cell.

Signal transduction pathway

The process of using signaling molecules to carry messages to target cells, involving receptors and chemical signaling in the cytoplasm.

Extracellular matrix

The substance that surrounds cells and provides structural support.

Cytoplasm

The fluid inside a cell where various cellular processes occur.

Intercellular junctions

Structures that connect neighboring cells and allow for communication and coordination.

Cell-cell recognition

The process by which cells identify each other using glycoproteins.

Enzymatic activity

The presence of enzymes in the cell membrane that facilitate chemical reactions.

Kinetic molecular energy (KME)

The energy that causes molecules to move.

Transport proteins

Proteins that facilitate the movement of chemicals in or out of the cell.

Passive transport

The movement of molecules without the use of energy.

Active transport

The movement of molecules using energy, typically ATP.

Uniporters

Transport proteins that move chemicals in one direction.

Symporters

Transport proteins that move two different chemicals in the same direction.

Antiporters

Transport proteins that move different chemicals in opposite directions.

Diffusion

The movement of substances from an area of high concentration to an area of low concentration.

Osmosis

The movement of water across a selectively permeable membrane.

Isotonic

A solution with a similar concentration of solutes as the surrounding environment.

Hypotonic

A solution with a lower concentration of solutes than the surrounding environment.

Hypertonic

A solution with a higher concentration of solutes than the surrounding environment.

Facilitated diffusion

The movement of solutes with the help of transport proteins.

Channel proteins

Proteins that create openings or tunnels for specific solutes to pass through.

Carrier proteins

Proteins that change shape to carry specific solutes across the cell membrane.

Active transport

The movement of solutes against their concentration gradient, requiring ATP.

Primary active transport

The use of ATP by a pump to move chemicals against their concentration gradient.

Secondary active transport

The movement of chemicals against their concentration gradient using the energy created by primary active transport.

Sodium-potassium pump

A specific example of active transport that moves sodium and potassium ions across the cell membrane.

Bulk transport

The movement of large-size chemicals or large quantities of chemicals across the cell membrane using vesicles.

Exocytosis

The process of releasing chemicals out of the cell using secretory vesicles.

Endocytosis

The process of bringing chemicals into the cell using vesicles.

Phagocytosis

A form of endocytosis that brings in large-sized substances into the cell.

Pinocytosis

A form of endocytosis that brings in large quantities of solutes into the cell.

Receptor-mediated endocytosis

A form of endocytosis triggered by the binding of a specific molecule to a receptor on the cell membrane.