Transporting channel of the cell

The correct option is B Endoplasmic reticulum The correct option is option B. Explanation of the correct option: • The endoplasmic reticulum (ER) is a network of membrane-bound tubules and sacs (cisternae) that extend from the nuclear envelope through the cytoplasm. • There are two types of endoplasmic reticulum: Rough endoplasmic reticulum and Smooth endoplasmic reticulum. • Ribosomes are connected to the rough endoplasmic reticulum, which aids in protein synthesis. • The endoplasmic reticulum plays a variety of roles in cells. • One of their primary tasks is to serve as a transportation channel. • Secretory proteins, most of which are glycoproteins, are transported through the endoplasmic reticulum membrane. • One of the functions of the ER is to act as a channel for material transport between different regions of the cytoplasm or between the cytoplasm and the nucleus. • The ER also serves as a cytoplasmic scaffold that provides a surface for some of the cell's biochemical activities. Explanation of the incorrect options: Option A: • Mitochondria are membrane-bound organelles found in the cytoplasm of all eukaryotic cells that create adenosine triphosphate (ATP), the cell's primary energy source • Controls the cell's metabolic activities. Option C: • The Golgi complex is a kind of organelle found in eukaryotic cells. • The Golgi complex modifies, sorts, and packages proteins for secretion. Option D: • Lysosomes are sphere-shaped sacs that contain hydrolytic enzymes that ...

Clc chloride channel ( Identifiers Symbol Voltage_CLC Available protein structures: Chloride channels are a superfamily of poorly understood in vivo is much higher than other anions. Voltage-gated chloride channels perform numerous crucial physiological and cellular functions, such as controlling pH, volume homeostasis, transporting organic solutes, regulating cell migration, proliferation, and differentiation. Based on General functions [ ] Voltage-gated chloride channels are important for setting cell Cl − or other anions such as HCO − 3, I −, SCN −, and NO − 3. The structure of these channels are not like other known channels. The chloride channel subunits contain between 1 and 12 transmembrane segments. Some chloride channels are activated only by voltage (i.e., voltage-gated), while others are activated by Ca 2+, other extracellular ligands, or pH. CLC family [ ] The CLC family of chloride channels contains 10 or 12 Structure and mechanism [ ] The CLC channel structure has not yet been resolved, however the structure of the CLC Each channel or exchanger is composed of two similar subunits—a dimer—each subunit containing one pore. The proteins are formed from two copies of the same protein—a homodimer—though scientists have artificially combined subunits from different channels to form heterodimers. Each subunit binds ions independently of the other, meaning conduction or exchange occur independently in each subunit. Each subunit consists of two related halves oriented...

• Biology • Cells • Transport Across Cell Membrane Transport Across Cell Membrane Cell membranes surround each cell and some organelles, such as the nucleus and the Golgi body. They are comprised of a phospholipid bilayer and this acts as a semipermeable barrier that regulates what enters and exits the cell or organelle. Transport across the cell membrane is a highly regulated process, that sometimes involves investing energy directly or indirectly to get the molecules that… Transport Across Cell Membrane • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Cell membranes s...

Here, the cell can't import glucose for free using diffusion, because the natural tendency of the glucose will be to diffuse out rather than flowing in. Instead, the cell must bring in more glucose molecules via active transport. In active transport, unlike passive transport, the cell expends energy (for example, in the form of ATP) to move a substance against its concentration gradient. Image depicting the charge and ion distribution across the membrane of a typical cell. Overall, there are more positive charges on the outside of the membrane than on the inside. The concentration of sodium ions is lower inside the cell than in the extracellular fluid, while the reverse is true for potassium ions. An electrical potential difference exists whenever there is a net separation of charges in space. In the case of a cell, positive and negative charges are separated by the barrier of the cell membrane, with the inside of the cell having extra negative charges relative to the outside. The membrane potential of a typical cell is -40 to -80 millivolts, with the minus sign meaning that inside of the cell is more negative than the outside 1 ^1 1 start superscript, 1, end superscript . The cell actively maintains this membrane potential, and we’ll see how it forms in the section on the sodium-potassium pump (below). As an example of how the membrane potential can affect ion movement, let’s look at sodium and potassium ions. In general, the inside of a cell has a higher concentration of...

Movement of Substances Across Cell Membrane The contents of a cell are completely surrounded by its cell membrane or plasma membrane. Thus, any communication between the cell and the extracellular medium is mediated by the cell membranes. These cell membranes serve two important functions: • It must retain the dissolved materials of the cell so that they do not simply leak out into the environment. • It should also allow the necessary exchange of materials into and out of the cell. There are two major methods for moving molecules across a membrane, and it is related to whether or not cell energy is used. Passive mechanisms, such as diffusion, require no energy to function, whereas active transport does. In passive transport, an ion or molecule crosses the membrane and moves down its concentration or electrochemical gradient. The different types of transport mechanisms across cell membranes are as follows: • Simple diffusion • Facilitated diffusion • Osmosis Diffusion Diffusion is a spontaneous process in which a substance moves from a region of high concentration to a region of low concentration, eventually eliminating the concentration difference between the two regions. Simple Diffusion Transport across the plasma membrane occurs unaided in simple diffusion, i.e., molecules of gases such as carbon dioxide and oxygen, as well as small molecules like ethanol, enter the cell by crossing the cell membrane without the assistance of any permease. A small molecule in an aqueous...

Have you been through airport security lately? If you have, you’ve probably noticed that it’s carefully designed to let some things in (such as passengers with tickets) and to keep others out (such as weapons, explosives, and bottled water). Flight attendants, captains, and airport personnel travel through quickly via a special channel, while regular passengers pass through more slowly, sometimes with a long wait in line. In many ways, airport security is a lot like the plasma membrane of a cell. Cell membranes are selectively permeable, regulating which substances can pass through, as well as how much of each substance can enter or exit at a given time. Selective permeability is essential to cells’ ability to obtain nutrients, eliminate wastes, and maintain a stable interior environment different than that of the surroundings (maintain homeostasis). The simplest forms of transport across a membrane are passive. Passive transport does not require the cell to expend any energy and involves a substance diffusing down its concentration gradient across a membrane. A concentration gradient is a just a region of space over which the concentration of a substance changes, and substances will naturally move down their gradients, from an area of higher to an area of lower concentration. In cells, some molecules can move down their concentration gradients by crossing the lipid portion of the membrane directly, while others must pass through membrane proteins in a process called facil...