Cell Structure & Function
- Cell Wall
- Extracellular Matrix
- Cell Junctions
- Tight Junctions
- Desmosomes
- Adhesion Plaques
- Gap Junctions
- Chemical Synapses
- Cytoplasm
- Cytoskeleton
- Glycolysis
- Microtubules
- Microfilaments
- Intermediate Filaments
- Centrioles
- Muscle Contractions
- Cytoplasmic Ribosomes
- Some Lab Sites
- General Links
- Mitochondria
- Endoplasmic Reticula
- Golgi
- Lysosomes
- Peroxisomes (Animals)
- Glyoxysomes (Plants)
- Chloroplasts
- Vacuoles
- Other
- Some Lab Sites
- General Links
- Membrane Proteins
- Endocytosis
- Exocytosis
- Phagocytosis
- Pinocytosis
- Transport
- Some Lab Sites
This is an occluding type of junction, where the plasma membranes of adjacent cells pinch tightly together. This creates a selective barrier between the spaces, allowing only certain materials to pass. Found often between cells of animal intestine, tight junctions assure that the correct chemical environment of intestinal lumen is maintained.
These are attachment sites that serve to anchor cells via intermediate filaments. The connecting intermediate filaments can form a continuous network throughout a tissue. Frequently, desmosomes are found in tissues that are subject to mechanical stress.
Desmosomes and Hemidesmosomes: Structure and Function of Molecular Components - A paragraph on the various aspects of desmosomes and hemidesmosomes.
Cell to Cell Junctions - A short discussion on cell junctions and provides a nice cartoon type image.
Actin filaments from the cell protrude and serve as the cell's anchor to the surrounding extracellular matrix.
In this type of junction, transmembrane proteins form a small (~1.5nm) pore between two cells. Six subunits of the protein connexin assemble to form a structure called a connexon. Two connexons on adjacent cells form a continuous channel between their cytoplasms, allowing small molecules to pass from one cell to the next.
These occur among adjecent cells when one cell releases chemicals into the extracellular space that bind receptors on the adjacent cell. This variety of cell-to-cell communication is common among nerve cells (See also Neurotransmission).
Synapses - Short descriptions of several types of cell synapses.
Neurotransmission
Neurotransmission is the passage of an electrical signal from a nerve cell (neuron) to another nerve cell, muscle or gland. In the process, chemicals called neurotransmitters, are released into the synapse (cleft between two neurons), where they bind receptors, changing the electrical potential in the membrane of the adjacent cell.