organelles


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organelles

specialized intracellular structures; e.g. mitochondria, Golgi apparatus, centrioles, granular and agranular endoplasmic reticulum, vacuoles, microsomes, lysosomes, plasma membrane and fibrils (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 ?
To address this growing need, GeneTex has developed a new line of subcellular and organelle marker antibodies that are highly specific to ribosomes, centrosomes, mitochondria (inner and outer membrane), the endoplasmic reticulum, the Golgi apparatus, kinetochores, lysosomes, microtubules/spindles, actin filaments, Cajal bodies, the nuclear envelope, the nucleolus and the nucleus.
Molecules that are to be broken down are enclosed in a membrane sack that forms an organelle called an autophagosome.
Content will cover molecules and organelles, tissues and organs, signal perception, plant and biotic environment, and information processing and acquisition.
Although there was extensive dilatation of the ER, other organelles such as mitochondria appeared morphologically normal.
Large granular areas of cytoplasm, relatively devoid of organelles and containing viral proteins and RNA, were noted in SARS-CoV-infected cells; such features have not been described previously for coronaviruses.
Taste buds are onion-shaped, multicellular organelles that project to the epithelial surface of the papilla.
It provides a basic overview of the organelles, tissues, and organ systems.
This article reviews several more cooperative and noncooperative symbioses, beginning with cellular organelles and moving to insects and plants.
Beyond simple cells, the Volocity software can also organize and relate measurements according to biological classification such as nuclei, membranes, organelles, and proteins, making it easier and faster to perform an analysis and understand the results.
In this proposed program I aim to study chemical processes in nano-sized protein cages as mimics of bacterial organelles and to increase the general understanding of chemistry in confinement.
These organelles are considered as the cells' power station.
Differential centrifugation followed by Percoll step gradient centrifugation works best to fractionate organelles.