Intracellular transport
Science has advanced tremendously in the last decade or so, specially in the field of cellular genetics. Even with such great advancements many scientists find that intracellular transport is a rather complex cellular process that requires parts such as a dynamic cytoskeleton, and molecular motor protein, which are myosin, kinesin, and dynein. In addition, intracellular transport involves the movement and selecting of vesicles and proteins to particular cellular regions. Sometimes intracellular transport happens over elongated distances, “like down the nerve axon” (Lodish). Occasionally this transport is simply the movement of a vesicle through the cell cortex. Transport also incorporates the suitable delivery and localization of organelles. The mitochondria serve as an example for such system of transportation within the organelles.
Cell movement incorporates whole-cell motion, the guideline of the cell shape and extracellular attachment. Cell migration is critical for several ordinary and pathological developments, embracing: cell and tissue development, wound restoration, immune reaction, and metastases of polyps/tumors (Intracellular Transport). Within cells, membrane-bounded vesicles and proteins are habitually transported many micrometers along distinct routes in the cytosol. These are later delivered to particular addresses. Diffusion alone is not the explanation for the rate, directionality, and targets of such transport processes. According to the Pennsylvania Muscle Institute, “Early video light microscopy studies showed that these long-distance movements follow straight paths in the cytosol” (Intracellular Transport). These are frequently found along cytosolic fibers, implying that Intracell...
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...eins and SNAREs. Kinesin, Dynein, and Intracellular Transport. Retrieved February 14, 2014, from http://www.ncbi.nlm.nih.gov/books/NBK21710/
Lodish, H. (n.d.). Kinesin, Dynein, and Intracellular Transport. Kinesin, Dynein, and Intracellular Transport. Retrieved February 14, 2014, from http://www.ncbi.nlm.nih.gov/books/NBK21710/
Sanderfoot, A., & Raikhel, N. (n.d.). The Specificity of Vesicle Trafficking: Coat Proteins and SNAREs. The Specificity of Vesicle Trafficking: Coat Proteins and SNAREs. Retrieved February 13, 2014, from http://www.plantcell.org/content/11/4/629.full
Vesicular transport and Golgi. (n.d.). Two Extreme Models- Vesicular Transport And Cisternal .... Retrieved February 13, 2014, from http://www.chegg.com/homework-help/questions-and-answers/extreme-models-vesicular-transport-cisternal-maturation-proposed-account-movement-molecule-q1246722
Margination and adhesion to the endothelium, in which accumulation of leukocytes occurs along the endothelial wall for adhesion. Afterward, these adhesions cause the separation of endothelial cells, allowing the leukocytes to extend and Transmigrate through the vessel walls. Followed by the response of chemical mediators(chemotaxis) that influence cell migration via an energy directed process which triggers the activation of Phagocytosis, in which monocytes, neutrophils, and tissue macrophages are activated to engulf and degrade cellular debris and
This cell membrane plays an important part in Diffusion. Cell membrane and Diffusion Diffusion is the movement of the molecules of gas or liquids from a higher concentrated region to a lower concentration through the partially permeable cell membrane along a concentraion gradient. This explanation is in the diagram shown below: [IMAGE] Turgor When a plant cell is placed in a dilute solution or a less concentrated solution then the water particles pass through the partially permeable membrane and fill the cell up with water. The cell then becomes Turgor or hard. An example of this is a strong well-watered plant.
This occurs when special carrier proteins carry solutes dissolved in the water across the membrane by using active transport. When the concentration gradient can not allow travel from one side of the membrane to the other fast enough for the cell’s nutritional needs, then facilitated diffusion is used. The transport protein is specialized for the solute it is carrying, just as enzymes are specialized for their substrate. The transport protein can be
When a cell membrane is said to be selectively permeable, it means that the cell membrane controls what substances pass in and out through the membrane. This characteristic of cell membranes plays a great role in passive transport. Passive transport is the movement of substances across the cell membrane without any input of energy by the cell. The energy for passive transport comes entirely from kinetic energy that the molecules have. The simplest type of passive transport is diffusion, which is the movement of molecules from an area of high concentration to an area of lower concentration. Diffusion
molecules go in and out of the cell. There is no net movement of water
On a cellular level, Mrs. Jones’ cells are dehydrated due to osmotic pressure changes related to her high blood glucose. Cells dehydrate when poor cellular diffusion of glucose causes increased concentrations of glucose outside of the cell and lesser concentrations inside of the cell. Diffusion refers to the movement of particles from one gradient to another. In simple diffusion there is a stabilization of unequal of particles on either side of a permeable membrane through which the particles move freely to equalize the particles on both sides. The more complex facilitated diffusion is a passive transport of large particles from a high concentration of particles to a lower concentration of particles with the aid of a transport protein (Porth, 2011). The cellular membranes in our bodies are semipermeable allowing for smaller molecules to flow freely from the intracellular to extracellular space. The glucose molecule, however; is too large to diffuse through the cellul...
The Importance of Diffusion to Living Organisms Diffusion is basically the movement of chemical species (ions or molecules) under the influence of concentration difference. The species will move from the high concentration area to the low concentration area till the concentration is consistent in the whole system. Diffusion mostly occurs in gases and liquids as these can move freely. The main features of an efficient diffusion system would be that it has a large surface area, thin membrane and a continuous supply of substances. A large surface area is needed so that high amount of substances can be exchanged at a time while the thin membrane means that the diffusion pathway would be short so that it is more efficient.
The F-actin inhibitor Latrunculin (identified as a toxin in the marine sponge Latrunculia magnifica) (Spector et al., 1983) enhances the rate of depolymerization of the actin network and prevents its polymerization (Yarmola et al., 2000). Jasplakinolide is cell permeable and has been used in live cells to explore the effect of filament disassembly in cell motility, cell adhesion and vesicle transport (Cramer, 1999). Latrunculin has been utilized to investigate the role of the actin cytoskeleton in cell migration, endocytosis and spindle orientation. Since the actin inhibitors cannot distinguish between muscle and cytoskeletal forms of actin, these are less common is clinics due to many undesirable off-target effects caused by the lack of specificity for the different types of actin. Regardless, the actin inhibitors are still useful on a cellular level in research studies to further the understanding of biological
Activity 3: Investigating Osmosis and Diffusion Through Nonliving Membranes. In this activity, through the use of dialysis sacs and varying concentrations of solutions, the movement of water and solutes will be observed through a semipermeable membrane. The gradients at which the solutes NaCl and glucose diffuse is unproportional to any other molecule, therefore they will proceed down their own gradients. However, the same is not true for water, whose concentration gradient is affected by solute ...
The Golgi Complex (or Golgi Apparatus, or Golgi Body) is a cytoplasmic structure composed of multiple cisternae (pools of solution surounded by membranes) arranged to look like a stack of pancakes hovering over the Endoplasmic Reticulum (ER). The Golgi Complex can be subdivided into three principal parts - cis, medial, and trans - based on proximity to the ER. The cis- and trans- Golgi stacks look discontinuous and irregular as vesicles are constantly joining and leaving, so they are usually referred to as the cis Golgi network (CGN) and trans Golgi network (TGN), respectively. The medial Golgi can have any number of cisternae, which are referred to collectively as the medial stacks. The function of the Golgi Complex is to modify proteins and then target them to specific sites in the cell.
The cytoskeleton is a highly dynamic intracellular platform constituted by a three-dimensional network of proteins responsible for key cellular roles as structure and shape, cell growth and development, and offering to the cell with "motility" that being the ability of the entire cell to move and for material to be moved within the cell in a regulated fashion (vesicle trafficking)’, (intechopen 2017). The cytoskeleton is made of microtubules, filaments, and fibres - they give the cytoplasm physical support. Michael Kent, (2000) describes the cytoskeleton as the ‘internal framework’, this is because it shapes the cell and provides support to cellular extensions – such as microvilli. In some cells it is used in intracellular transport. Since the shape of the cell is constantly changing, the microtubules will also change, they will readjust and reassemble to fit the needs of the cell.
Cellular membranes are complex mixtures of proteins and lipids. Cell membranes are composed of a phospholipid bilayer, consists of two leaflets of phospholipid molecules and their fatty acid chain form the hydrophobic interior of the membrane bilayer; and proteins that span the bilayer and/or interact with the lipids on either side of the two leaflets. Transmembrane proteins are the type of membrane proteins which span the entire length of the cell membrane. They are embedded between the phospholipids and provides a channel through which molecules and ions can pass into the cell. They enable communication between cells by interacting with chemical messengers. Membrane proteins were classified into two comprehensive categories- integral and
Synaptic vesicles exist in different types, either tethered to the cytoskeleton in a reserve pool, or free in the cytoplasm (Purves, et al., 2001). Some of the free vesicles make their way to the plasma membrane and dock, as a series of priming reactions prepares the vesicular and plasma membrane for fusion (Lodish, Berk, Zipursky, Matsudaira, Baltimore, & Darnell, 2000).
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. But it also contains highly organized physical structures which are called intracellular organelles. These organelles are important for cellular function. For instance Mitochondria is the one of most important organelle of the cell. Without Mitochondria more than 95% of the cell’s energy, which release from nutrients would cease immediately [Guyton et al. 2007].
All types of cilia have a length of about 10-15 μm and comprises of the same basic structure. A cilium is a microtubule-based organelle, which extends from a microtubule organizing chamber- the basal body, a centriole and at the apical surface of the cell bears microtubule cytoskeleton called the ciliary axoneme surrounded by a specialized ciliary membrane. The primary or the non-motile cilia consist of the ‘9+0’ arrangement of the axoneme, with the normal nine outer microtubule doublets and no central microtubule pair. Since the primary cilia are non-motile, therefore they usually lack dynein arms and radial spokes connected to the microtubule doublets. Primary cilia can receive signals from the extracellular biochemical and physical environments. Nodal cilia like primary cilia, occur solitary, having the 9+0 arrangement of axoneme, however, nodal cilia bears L, R...