Bio exam 3 Cell-Cell interactions part 2

G-protein-coupled receptor (GPCR)

A receptor that activates G proteins when a signal molecule binds to it.

Protein kinase

An enzyme that adds phosphate groups to other proteins to activate or deactivate them.

Phosphorylation cascade

A series of protein activations through phosphorylation, amplifying the signal inside the cell.

Enzyme-linked receptor

A transmembrane receptor that directly catalyzes a reaction inside the cell when activated.

Receptor tyrosine kinase (RTK)

A type of enzyme-linked receptor that phosphorylates proteins to trigger signal transduction.

Ras protein

A small GTP-binding protein that links RTK activation to a phosphorylation cascade.

Mitogen

A signaling molecule that stimulates cell division.

MAP kinase (Mitogen-Activated Protein Kinase)

A kinase activated in a phosphorylation cascade that promotes cell division.

Signal response

The final outcome of a signaling pathway that changes gene expression or protein activity.

Signal deactivation

Mechanisms that turn off signaling pathways, such as phosphatases removing phosphate groups.

Phosphatase

An enzyme that removes phosphate groups from proteins to deactivate signaling pathways.

Crosstalk

Interaction between different signaling pathways allowing integration and coordination of cellular responses.

Quorum sensing

Communication among unicellular organisms in response to population density through signaling molecules.

Biofilm

A community of microorganisms attached to a surface, often formed through quorum sensing.

Slime mold

A unicellular organism that uses quorum sensing to aggregate and coordinate behavior.

Turgor pressure

The pressure exerted by water inside the plant cell against the cell wall.

Fiber composite

A network of fibrous components and ground substance that provides structural support.

Ground substance

The gel-like material that resists compression in the ECM or plant cell wall.

Cytoskeleton

A network of protein filaments inside the cell that maintains shape and connects to the ECM.

Epithelia

Tissues that line body surfaces and rely on tight junctions and desmosomes for structure.

Multicellularity

The condition where cells cooperate and communicate to function as an interdependent community.

Signal amplification

The strengthening of a signal as it is passed along a transduction pathway.

Dynamic receptor

A receptor whose number or sensitivity can change over time.

Beta-blocker

A drug that inhibits the interaction between hormones and their receptors.

Hormone-receptor complex

The combination of lipid-soluble hormone and its intracellular receptor that alters gene expression.

Extracellular signal

A signal molecule outside the cell that triggers a response.

Intracellular message

The signal generated inside the cell in response to an external signal.

Signal molecule

Any chemical messenger that carries information from one cell to another.

Gene expression change

A slow cellular response involving the production of new proteins.

Protein activity change

A fast cellular response involving the activation or deactivation of existing proteins.

Electrical signal

A rapid form of communication in excitable cells mediated by ion movement.

Receptor downregulation

A decrease in the number of receptors on a cell surface, reducing sensitivity to a signal.

Receptor upregulation

An increase in receptor number, making the cell more sensitive to a signal.

Symplastic transport

Movement of substances between plant cells through the symplast (shared cytoplasm).

Apoplastic transport

Movement of substances through cell walls and spaces outside membranes in plants.

Signal integration

The combination of multiple signals within a cell to produce a coordinated response.

Unicellular signaling

Communication between single-celled organisms through released signaling molecules.

Species-specific signal

A chemical used in quorum sensing that is unique to one species.

Population density signaling

A communication process in which the concentration of signaling molecules indicates cell population size.