Cell Structure & Function
- General Links
- Membrane Proteins
- Endocytosis
- Exocytosis
- Phagocytosis
- Pinocytosis
- Transport
- Some Lab Sites
- 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
The plasma membrane has been called an asymmetric fluid mosaic structure. Made from two leaflets of lipids that form a bilayer (see also Lipid Biosynthesis), it contains proteins that can span one or both layers or are peripherally attached to one face or the other. The components of the bilayer frequently move laterally into other regions of the membrane, making it appear more fluid than static. In addition, proteins on the extracellular face can be heavily glycosylated, giving the membrane asymmetrical characteristics.
Image of Plasma Membrane - A large cartoon image of a cell membrane, followed by an in depth discussion on each component making up the membrane, the chemical compounds present, and the mechanisms which the plasma membrane carries out.
Structure of Cell Membranes - Provides several historically different models of cell membranes, along with short descriptions of each one.
Serotonin: The Neurotransmitter for the '90s - Focuses on the history of serotonin, a neurotransmitter. Includes a detailed discussion on serotonin itself, along with background on each of its different receptor systems.
WWW Cell Biology Course - Possesses anchors to pages with cartoon like images of various cell membrane structures, accompanied by a short description on each function. In addition, this page provides a couple of links which the author feels may be of some use.
The Plasma Membrane and Cellular Transport - An advertisement for a computer program, which teaches students about the structure and function of the membrane.
Protoplast Production - Activity for High School students to see plant plasma membranes.
Membranes - Provides a cartoon like illustration of a plasma membrane, accompanied by important notes on the different structures making up, and the functions of, the membrane.
The Cell Membrane: The Gate Keeper - A short overview of the cell membrane's functions and chemistry.
Surface Specializations - An excellent site!!! Provides lots of important information on almost every aspect of the plasma membrane. Also provides lots of large (they download very fast) and helpful images, and numerous relevant links.
Plasma Membrane Resealing in Muscle Cells & the Roles of Vesicle-Associated Proteins - An actual lab performed on plasma membrane repair. This write-up includes an abstract of the overall experiment. It also includes the procedures followed, the results, and interpretation of the results.
Enzyme Proteins - Provides a discussion on various membrane proteins. Also provides several related links.
The G-Protein Coupled Receptor Database - Provides an in depth discussion of almost all G protein-coupled receptors.
Membrane Proteins - Focuses its discussion of transmembrane proteins, includes discussions on background information, transmembrane protein structure, and their roles in the cell.
This is the uptake or internalization of materials by a cell. The plasma membrane forms a small pocket or infolding around the material to be internalized. A vesicle forms after the cell pinches off the infolded membrane, and the enclosed materials are then sorted to the interior of the cell.
Receptor Mediated Endocytosis - A discussion on receptor mediated endocytosis; includes the roles of several components in this process and a sample self test.
| Endocytosis Movie(29K) |
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Endocytosis of Neutrophil - Provides a nice image of endocytosis.
Endocytosis of Neutrophil...Part 2 - Provides a nice image of endocytosis.
Endocytosis - Provides brief introductions to endocytosis, phagocytosis, and pinocytosis. Includes two examples of receptor-mediated endocytosis.
Transport of Large Molecules - Discusses transportation of molecules through endocytosis and exocytosis. Includes short discussions on other cellular molecules: LDL, Transferrin, and Antibodies.
Membrane Fusion, Fission, Endocytosis, & Viral Uptake - Provides anchors to pages that focus on various types of membrane fusions. Also includes links to membrane fission, endocytosis, and viral uptake.
In this process, materials or products are transported from inside the cell to the outside. Vesicles fuse with the inside layer of the plasma membrane, which ruptures, emptying the vesicular contents outside the cell. Secretory cells utilize this method to release their products.
| Exocytosis Movie(31K) |
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In this form of endocytosis, large macromolecules, microorganisms, cell parts, or whole cells can be engulfed by a single cell. This process frequently occurs in prokaryotes and single-celled eukaryotes to obtain food, and in some of the immune system cells of complex eukaryotes for defense or removal of materials.
Dynamic Redistribution of the Cytoskeleton During Phagocytosis - Provides a short discussion on the function of the cytoskeleton. This is followed by another short discussion on work performed on coronin.
The Chronic Candidiasis Syndrome - This is a highly specialized page aimed primarily at physicians. It focuses completely on a disease known as Chronic Candida Syndrome.
Cytokines & Interferon - Provides a brief introduction to cytokinesis, accompanied by a discussion on interferon and cytokinesis defenses.
Polymorphonuclear Phagocytosis & Killing in Workers Exposed to Inorganic Mercury - An abstract of a study performed using Candida species to examine the effects of mercury on miners.
Dynamic Redistribution of the Cytoskeleton during Phagocytosis - Provides a short discussion on the function of the cytoskeleton. This is followed by another short discussion on the work they have performed on coronin.
In this specialized form of endocytosis, liquids, solutes, or suspended particles are brought into the cell. As in other types of endocytosis, vesicles assemble around the incoming materials when the plasma membrane folds inward, pinches together, and subsequently detaches inside the cell.
In this process, materials move across a membrane, such as the plasma membrane or nuclear envelope. Two major types of transporters, carriers and channels can be differentiated based on whether or not they use active transport, which means they require chemical energy such as ATP. Carriers are often active transporters, whereas, channels always use passive methods of transport and, thus, do not require the additional energy.
Oxygen Delivery from the Blood to the Muscle Fibers - Discusses how oxygen behaves in the blood stream.
Transport in and out of Cells - Focuses the discussion on the movement of elements across the plasma membrane. Includes the introduction of a number of important terms, possesses several nice cartoon type images of various types of cellular transport, and provides additional links.
Transport of Proteins Across Membranes - Possesses a lot of information on the transport of proteins across membranes, endoplasmic reticulum, signal peptides, cotranslation transport, posttranslational transport, uncleaved signal sequences, signal recognition particles, prokaryotic signal sequences, and proteins synthesized by free ribosomes in the cytoplasm.
| Active Transport Movie(34K) |
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| Diffusion Movie(13K) |
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Dr. Peter Novick's Lab - Mechanism of Plasma-Membrane Assembly and Cell Surface Organization in Yeast
Dr. Robert Josephs' EM Lab - Laboratory for Electron Microscopy Image Analysis
Dr. J.B. Lloyd, C.L. Andrew, A.R. Klemm - Permeability of the Lysosome Membrane
Lund University Faculty of Medicine - Cellular Regulation of Pinocytosis
Sebastian Y. Bednarek - Plant Cell Biology
Bruce L. Granger, Sarah J. Warwood, and Donald E. Burgess - Discusses work that they have done on endocytosis in a protozoan parasite that causes the venereal disease: Tritrichomonal foetus.
University of Cambridge Department of Pharmacology