cell structure


Also found in: Encyclopedia, Wikipedia.

cell structure

see CELL.

cell structure

common intracellular features (nucleus, cytoplasm, cell membrane) and organelles (endoplasmic reticulum, lysosomes, mitochondria, microtubules, Golgi apparatus) which facilitate specialist function (see Table 1)
Table 1: Cell organelles
StructureCharacteristic
Cell membraneBimolecular lipid and protein membrane that surrounds the cell
• Bi-layer of non-polar lipid molecules (phosphatidylcholine, phospharidylethanolamine, cholesterol) that acts as a barrier to water and hydrophilic solutes
• Proteins:
  • Structural proteins

  • Protein pumps that actively transport ions such as sodium out of the cell

  • Carrier proteins that carry molecules such as glucose into the cell

  • Ion channel proteins, such as sodium ion channels in nerve fibres to which molecules of local anaesthetic attach to prevent the passage of the pain-inducing nerve impulse

  • Receptor proteins, such as insulin receptors which facilitate the passage of glucose into the cell

  • Immunoglobulin proteins, which form part of the immune response mechanism

  • Enzyme proteins, such as alkaline phosphatase

Cell cytoplasmThe gel-like matter contained within the membrane envelop:
• Contains and supports specialized organelles, including the cell nucleus, endoplasmic reticulum, the Golgi apparatus, mitochondria and lysozomes
• Stores substances (glycogen and lipids)
• Synthesizes and metabolizes essential substances (amino acids, fatty acids, monosaccharides)
• Synthesizes and translates protein
• Contains microtubules which help maintain the form of the cell and form intercommunication channels between organelles
Cell cytoskeletonA complex network of structural elements (microtubules, intermediate filaments and microfilaments) which determine the shape of the cell, its ability to move and its response to external stimuli
Cell nucleusPresent in all eukaryotic cells capable of mitosis
Contains the cell genome (DNA) and the means of replication and transcription of RNA
Separated from the cytoplasm by the nuclear envelop (which disappears during mitosis and meiosis)
Contains the nucleolus, where ribosomes are synthesized
Intercellular connectionsThere are two types of intercellular connections: tight junctions and gap junctions
Cell adhesion molecules (CAMs)Structures (receptor integrins, immunoglobulin adhesion molecules, Ca+-dependent cadherins and carbohydrate-binding selectins) within the cell membrane that bond to laminins within the extracellular matrix to attach adjacent cells to one another and to the basal membrane
References in periodicals archive ?
By optimizing the CX6000 logic cell structure, clock networks and floor plan for Magma's synthesis, placement and clock tree synthesis engines, designers can take full advantage of regular cell structures and available on-chip resources.
PK ) have developed a new solar cell structure that will simplify the production process, significantly lower costs, and speed the path toward ultra high-efficiency cells.
Fraunhofer ISE has now created high-efficiency cell structure that evades the use of a costly silver contact grid on the back of the cell.
Additional objectives are to show that a well balanced blowing agent concentrate is effective at developing a good quality low density foam using PLA modified with an acrylic melt strength enhancer and how it affects the cell structure and surface quality of a free foamed extruded profile.
Compared with some fluorocarbon, hydrocarbon, or other liquid physical foaming agents, Cylacell reportedly can show improved cell structure, lighter foam densities, and sometimes higher flame retardancy and smoke suppression.
That results in a product with much less moisture, a moderated cell structure and reduced sugar levels that render them useless to insects and rot fungi, eliminating the need for chemical preservatives or pesticides.
The 32-megabit device features a ''chained'' memory cell structure expected to facilitate further advances to higher-density FeRAM, the company said.
6 GHz frequency standard using a vertical-cavity surface-emitting laser (VCSEL) that pumps a cesium atomic vapor in a small cell structure.
Scientists studying a freshwater microbe have discovered a tiny cell structure that serves as a garbage disposal for unwanted genetic material.
7 percent efficient cell was developed using a multi-junction solar cell structure.
Actifoam has a closed cell structure, so it cannot absorb any moisture.
The scientists then measured expression of several key genes involved in neurologic function, apoptosis, endocrine function, cell cycle regulation, cell structure, and metabolism.