Extracellular Matrix and Cell Junctions

These flashcards cover key vocabulary related to the extracellular matrix and cell junctions, providing definitions for better understanding and memorization.

Extracellular Matrix (ECM)

A complex network of proteins and polysaccharide chains that cells secrete, providing structural and biochemical support.

Prokaryotic Cells

Cells that lack a nucleus and other membrane-bound organelles, characterized by a rigid extracellular matrix mainly composed of peptidoglycan.

Plant Cell Wall

An elaborate extracellular matrix that provides support and protection to plant cells, primarily made of polysaccharides.

Animal ECM Components

Composed mainly of fibrous proteins, proteoglycans, and polysaccharides.

Turgor Pressure

The pressure exerted by the fluid inside a plant cell against its cell wall, crucial for maintaining plant structure.

Cadherins

Transmembrane proteins that mediate cell-cell adhesion by forming adherens junctions.

Desmosomes

Anchoring junctions in animal cells that connect intermediate filaments of the cytoskeleton of adjacent cells.

Plasmodesmata

Cellular channels in plant cell walls that connect adjacent cells and allow for transport and communication.

Hemidesmosomes

Attach cells to the extracellular matrix, linking intermediate filaments of the cytoskeleton to the ECM.

Gap Junctions

Cell junctions that form channels between adjacent cells, allowing for direct communication and transfer of ions and small molecules.

Proteoglycans

Highly hydrated macromolecules in the ECM, consisting of a core protein bonded to glycosaminoglycan (GAG) chains.

Collagen

A structural protein that forms fibers in the ECM, providing tensile strength to tissues.

Elastin

A protein that provides elasticity to tissues, allowing them to stretch and recoil.

Hyaluronic Acid

A glycosaminoglycan that contributes to the hydration and swelling pressure of the ECM.

Middle Lamella

A layer that cements together the primary cell walls of adjacent plant cells.

Cytoskeleton

A network of fibers within animal cells that provides structural support, shape, and facilitates cell movement.

Integrins

Transmembrane proteins that mediate cell-ECM adhesion.

Tight Junctions

Specialized connections between epithelial cells that prevent substances from passing between them.

Adherens Junctions

Connections between adjacent epithelial cells that involve actin filaments and cadherins.

Cytokinesis

The process during cell division where the cytoplasm divides to form two daughter cells.

ECM's Role

Beyond offering support, the ECM actively regulates cellular behaviors such as survival, development, and migration.

Secondary Cell Wall

A thicker and more rigid wall deposited when plant cells cease to grow, often containing lignin.

Primary Cell Wall

The flexible and thin layer that surrounds the cytoplasm of a young plant cell.

Cohesive Forces

Forces that hold cells together in tissues against external mechanical stress.