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Cell Movement: The movement of cells from one location to another. Distinguish from Cytokinesis which is the process of dividing the Cytoplasm of a cell.

Diffusion and Osmosis- Concept

JoVE 10622

Cell Membranes and Diffusion

In order to function, cells are required to move materials in and out of their cytoplasm via their cell membranes. These membranes are semipermeable, meaning that certain molecules are allowed to pass through, but not others. This movement of molecules is mediated by the phospholipid bilayer and its embedded proteins, some of which act as transport channels…

 Lab Bio

Cell Structure- Concept

JoVE 10587

Background

Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, multicellular organisms like elephants and giant redwood trees. In the mid 19th century, the Cell Theory was proposed to define a cell, which states:



Every living organism is made up of one or more cells.
The cells…

 Lab Bio

Cell Migration

JoVE 10911

Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.

Generally, cellular migration begins when a cell, such as a fibroblast, responds to an external-polarizing-chemical signal. As a result, one end extends itself as a protrusion called the leading edge, which attaches itself to substrates via secreted adhesive compounds, in its microenvironment. The trailing edge—the area that serves as the back of the cell—also adheres to substrates to anchor the cell. After adhesion, the cell is propelled towards its destination by a sequence of contractions that are generated by cytoskeletal motility structures. Then, the adhesive attachment at the trailing edge gets released. These steps are repeated cyclically until the fibroblast reaches its destination. There is a diversity in the different types of signaling molecules that initiate cell migration. They illicit two types of responses: chemokinetic and chemotactic. Chemokinesis refers to movement that occurs when signaling molecules either symmetrically or asymmetrically stimulate cell

 Core: Biology

Using Diffusion Tensor Imaging in Traumatic Brain Injury

JoVE 10276

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California


Traditional brain imaging techniques using MRI are very good at visualizing the gross structures of the brain. A structural brain image made with MRI provides high contrast of the borders between gray and white matter, and information about…

 Neuropsychology

Galvanic Cells- Concept

JoVE 11177

Electrochemistry


Electrochemistry is a branch of chemistry that studies the relationship between electrical energy and a chemical change. These chemical reactions involve the movement of electrons from one species to another. This movement either generates current, or it is driven by applied current.


The key reaction in electrochemistry is the…

 Lab: Chemistry

An Introduction to Cell Motility and Migration

JoVE 5643

Cell motility and migration play important roles in both normal biology and in disease. On one hand, migration allows cells to generate complex tissues and organs during development, but on the other hand, the same mechanisms are used by tumor cells to move and spread in a process known as cancer metastasis. One of the primary cellular machineries that make cell movement…

 Cell Biology

Electrolytic Cells- Concept

JoVE 11180

Electrochemistry


Electrochemistry is a branch of chemistry that describes and measures the relationship between electrical energy and a chemical change. Electrochemical reactions involve the movement of electrons from one species to another. If the reaction is spontaneous, it can result in a generated current. If the reaction is not spontaneous, it can be driven…

 Lab: Chemistry

Short-distance Transport of Resources

JoVE 11097

Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole. Resources are transported into and out of the central vacuole within each plant cell One of the roles of the large central vacuole of a plant cell is the storage of resources. Active and passive transport proteins are found in the vacuolar membrane, or tonoplast, just as they are found in the plasma membrane of the cell, and they regulate the movement of solutes between the cytoplasm and vacuole. Sugar can be stored for later, ions are sequestered from the cytoplasm, and protons, in particular, are pumped into the vacuole, creating an acidic environment for breaking down unwanted or toxic substances that enter the cell. Movement across the tonoplast controls turgor pressure In addition to its role in storage, the vacuole generates turgor pressure - a force that pushes the plasma membrane against the cell wall -

 Core: Biology

The Apoplast and Symplast

JoVE 11106

Plant growth depends on its ability to take up water and dissolved minerals from the soil. The root system of every plant is equipped with the necessary tissues to facilitate the entry of water and solutes. The plant tissues involved in the transport of water and minerals have two major compartments - the apoplast and the symplast. The apoplast includes everything outside the plasma membrane of living cells and consists of cell walls, extracellular spaces, xylem, phloem, and tracheids. The symplast, in contrast, consists of the entire cytosol of all living plant cells and the plasmodesmata - which are the cytoplasmic channels interconnecting the cells. There are several potential pathways for molecules to move through the plant tissues: The apoplastic, symplastic, or transmembrane pathways. The apoplastic pathway involves the movement of water and dissolved minerals along cell walls and extracellular spaces. In the symplastic route, water and solutes move along the cytosol. Once in this pathway, materials need to cross the plasma membrane when moving from cell to neighboring cell, and they do this via the plasmodesmata. Alternatively, in the transmembrane route, the dissolved minerals and water move from cell to cell by crossing the cell wall to exit one cell and enter the next. These three pathways are not mutually exclusive, and some solutes may use more than on

 Core: Biology

The Resting Membrane Potential

JoVE 10845

The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.

The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The membrane potential of a neuron at rest—that is, a neuron not currently receiving or sending messages—is negative, typically around -70 millivolts (mV). This is called the resting membrane potential. The negative value indicates that the inside of the membrane is relatively more negative than the outside—it is polarized. The resting potential results from two major factors: selective permeability of the membrane, and differences in ion concentration inside the cell compared to outside. Cell membranes are selectively permeable because most ions and molecules cannot cross the lipid bilayer without help, often from ion channel proteins that span the membrane. This is because the charged ions cannot diffuse through the uncharged hydrophobic interior of membranes. The most common intra- and extracellular ions found in the nervous tissue are potassium (K+), sodium (Na+…

 Core: Biology
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