Hi Hi Hi Have you ever wondered how a molecule or particle can enter and exit a cell? Well, cells have a plasma membrane that acts as a fence that regulates the process of molecules entering and leaving the cell. So, let's take a closer look at the plasma membrane. Hi, the basic structure of the plasma membrane is a tent layer lipid, which means the plasma membrane has two layers of lipids. The large part of the lipid in the plasma membrane is a phospholipid that has a polar head and a nonpolar tail. Because of this structure, the plasma membrane is selectively permeable, which means that the plasma membrane can be easily passed by certain molecules but cannot be passed easily by other molecules. Non-polar molecules and small molecules are one type of molecule that can pass through the cell membrane easily, but large molecules and polar molecules cannot pass through the plasma membrane just like that. So, how exactly is the regulation of molecular transport through Isma? Well, let's take a look together about membrane transport. There are several membrane transport mechanisms. The first mechanism is passive transport. In passive transport, molecules move down their concentration gradient, namely from an area with a high concentration to an area with a low concentration. For non-polar molecules, they can easily penetrate the plasma membrane and down their concentration gradient. This movement of molecules down their concentration gradient. called simple diffusion for polar molecules and large molecules to penetrate the plasma membrane they need the help of a protein for polar molecules such as sodium ions potassium ions and calcium ions they penetrate the plasma membrane through the process of facilitated diffusion Hi by means of proteins namely transmembrane proteins that have open pores that are specific for certain ions only while large molecules such as glucose and amino acids they penetrate the plasma membrane with the help of carrier proteins when the molecule binds to the carrier protein the protein will change its shape in this case the protein that was originally open to the extracellular direction changes shape so that it opens to the intracellular direction so that the molecule can be transformed into the cell this transport process is also called facilitated diffusion because the molecule moves down its concentration gradient facilitated by the carrier protein well simple diffusion and facilitated diffusion play a role in the transport of molecules to move down its concentration gradient, namely from an area with a high concentration to an area with a low concentration in the process of moving molecules through these two processes which are included in passive transport does not require energy then What if a cell needs extracellular molecules which turn out to have a lower concentration outside than inside the cell well in this case the molecule will be transported through the process of active transport because the molecule moves against its concentration gradient, namely from area with low concentration to high concentration So energy is needed in the process one of the energy sources used to carry out active transport is ATP KTP or adenosine triphosphate is a molecule that has three phosphate groups if ATP undergoes hydrolysis to ADB Hi and releases one phosphate group then there will be a release of energy that can be used to carry out active transport there are two types of active transport namely primary and secondary active transport in primary active transport the energy source used is ATP an example of primary active transport that is quite popular is the sodium-potassium pump the sodium-potassium pump transports sodium ions and potassium ions against their respective concentration gradients namely sodium ions will go out of the cell while potassium ions will enter the cell there is a sodium-potassium pump three sodium ions from inside the cell will bind to the sodium-potassium pump which is then followed by ATP hydrolysis ATP hydrolysis into e-ktp and the transfer of phosphate groups to the sodium-potassium pump will result in changes in the shape of the sodium-potassium pump the sodium-potassium pump will open towards the extracellular sodium ions Then dissociate from the sodium-potassium pump to go out of the cell potassium ions from outside the cell then bind to the Atrium potassium component and followed dissociation of the phosphate group from the sodium-potassium pump the sodium-potassium pump will return to its original form, namely open towards intracellular potassium ions Then dissociate from the sodium potassium pump and go into the cell the sodium-potassium pump is ready to carry out the next cool Transformers cycle Trans Hai active the second is secondary active transport in secondary active transport the energy source used to the origin of the movement of other molecules down its concentration gradient there is the first example Energy derived from the movement of Na ions down its concentration gradient will be used as an energy source to transfer glucose against its concentration gradient the bond of Na and glucose ions with the carrier protein will change the carrier protein so that it opens towards intracellular Na and glucose ions Then dissociate from the carrier protein to go to the intracellular well this active transport process is also called simple because the molecules being transported move in the same direction there is a second example the movement of Na ions down its concentration gradient is used to transfer rioncha against its concentration gradient Na ions from the extracellular and C-ions from the intracellular bind to the carrier protein the change in shape of the carrier protein allows Na ions to go to the intracellular while Ca2 ions go to the extracellular because in this transport process there are two molecules that move in opposite directions this transport process is also called antipor Now what if the cell wants to transfer very large molecules such as bacteria or what if the cell wants to transport a large number of molecules at once, well in this case the cell will use transport with vesicles, vesicles or vesicles are a structure coated with double-layer lipids and can contain fluids or particles, well the transport with vesicles that we will discuss first is exocytosis, namely the transport of molecules from inside the cell to the outside of the cell through vesicles, there is exocytosis, the risk that comes from the intracellular will move towards the plasma membrane, the vesicle membrane then functions with the plasma membrane, the molecules in the vesicle can then exit to the extracellular transport with the second vesicle is endocytosis Hi Sis, namely Transformers cool from outside to inside the cell through vesicles in this process the cell will cover the molecules or particles that will be transferred into the cell with a plasma membrane, there are several types of endocytosis, the first type of endocytosis is phagocytosis comes from the word phage in which means to eat in this phagocytosis process, the cell will eat molecules or particles that are very large, for example bacteria, well phagocytosis This can only be done by several types of cells. For example, macrophages. The second type of endocytosis is pinocytosis, namely fluid endocytosis. Hi, even though the induced tosis is fluid, particles and molecules can also be transported through this mechanism. The third type of endocytosis is receptor-mediated endocytosis. In this mechanism, the particles that will be Indosat OSIS will first bind to the receptors on the cell surface. So, those are the various membrane transport mechanisms, which in general are three, namely passive transport, active transport, and transport with various types of transformium and this plays a role in regulating the entry and exit of molecules from and into cells so that homeostasis can be maintained in sufficient quantities.