Cell-Cell Interactions and Communication in Biology

Cell-Cell Interactions

Communication and cooperation among cells.

Extracellular Layer

Structure beyond the plasma membrane.

Cell Walls

Provide structure and protection for cells.

Extracellular Matrix

Fiber composite providing structural support.

Tight Junctions

Form watertight seals between epithelial cells.

Desmosomes

Connect cytoskeletons of adjacent cells.

Gap Junctions

Channels allowing direct communication between cells.

Plasma Membrane

Phospholipid bilayer controlling material flow.

Integral Proteins

Proteins embedded within the plasma membrane.

Peripheral Proteins

Proteins attached to the membrane surface.

Turgor Pressure

Pressure from fluid in plant cells.

Expansins

Proteins that disrupt hydrogen bonds in cell walls.

Primary Cell Wall

First layer of plant cell structure.

Secondary Cell Wall

Layer secreted for additional support in specific cells.

Lignin

Rigid substance found in secondary cell walls.

Collagen

Main protein fiber in the extracellular matrix.

Proteoglycans

Gelatinous polysaccharides forming ECM ground substance.

Cytoskeleton

Network providing structural support within cells.

Integrins

Proteins linking cytoskeleton to extracellular matrix.

Middle Lamella

Layer gluing adjacent plant cells together.

Epithelial Tissue

Covers organs and lines body cavities.

Cell Communication

Essential for coordinated function in tissues.

Selective Adhesion

Specific attachment of cells via adhesion proteins.

Adhesion Proteins

Proteins that mediate cell-to-cell attachment.

Cadherins

Adhesion proteins involved in cell-cell adhesion.

Antibodies

Proteins that bind specifically to target molecules.

Signal Reception

Initial binding of hormones to signal receptors.

Signal Processing

Transduction of signals within the cell.

Signal Response

Cell's action following signal reception.

Signal Deactivation

Mechanisms to turn off cell signaling.

Hormones

Long-distance chemical messengers in the body.

Second Messengers

Small molecules amplifying hormone signals.

G Proteins

Membrane proteins activated by GTP.

Enzyme-Linked Receptors

Receptors that activate intracellular signaling pathways.

Phosphorylation Cascade

Series of phosphorylation events amplifying signals.

Crosstalk

Interaction between different signaling pathways.

Quorum Sensing

Bacterial communication based on population density.

Signal Amplification

Increasing signal strength through second messengers.

Phosphatases

Enzymes that remove phosphate groups from proteins.

Cell-Cell Signaling Steps

Four stages: reception, processing, response, deactivation.

Receptor Tyrosine Kinase (RTK)

A type of enzyme-linked receptor for signaling.

Intracellular Signaling Molecules

Molecules that relay signals within the cell.

Lipid-Insoluble Signaling

Signaling involving molecules that cannot cross membranes.

Target Genes

Genes affected by signaling pathways.

Cell Adhesion

Process by which cells attach to each other.

Signal Receptors

Proteins that bind signaling molecules.

Hormonal Effects

Diverse physiological responses triggered by hormones.

Microbial Biofilms

Communities of microbes adhering to surfaces.

Slug-like Body

Aggregated cells in slime molds for movement.