Summary of Transporte en membrana

00:00:00 - 00:30:00

This video discusses how various molecules are transported through cellular membranes, including passive and active transport. It also explains how water moves through the body and how concentration affects this movement.

• 00:00:00 In this video, we will explore the movement of molecules through cellular membranes. We will remember that a membrane has a bilayer of lipids and within it there are several molecules of various types. This is called a mosaic, and there are proteins, peripheral integral proteins, and carbohydrate-binding proteins. We will discuss two types of transport in the membrane: passive and active. Passive transport goes in favor of a concentration gradient, while active transport consumes energy and moves from a lower concentration to a higher concentration. We will see examples of molecules moving through membrane transport in this video. We will discuss diffusion, which is the movement of molecules through a membrane, in more detail in the next video.
• 00:05:00 In this video, we learn that the simple transport of molecules across a lipid bilayer is possible through other molecules that can achieve it, such as urea, ethanol, or hormones. Remember diffusion? It's the movement of a concentration of high to low concentration of molecules across a surface. Unlike osmosis, diffusion does not require energy. We also remember that there are differences between diffusion and osmosis in that diffusion are molecules, while osmosis is the movement of water molecules. We also learn that transport through a lipid bilayer is facilitated by proteins that act as transport channels, and that there are some molecules that are not polar and cannot cross the membrane, such as ions and large molecules like proteins. Finally, we learn that transport is active when cells need to move molecules against a concentration gradient, and that this requires the use of transport channels made up of proteins.
• 00:10:00 This video explains how transportadores, or "transporters," use ATP to move proteins across cell membranes. These transporters consume ATP to facilitate their task, and remember that these "transporters" are ATPases to make proteins that can travel through the lipid bilayer. There are several transporter models discussed, including an "anti-port" transporter and one that imports ATP. In the anti-port transporter, one molecule goes in the opposite direction of the other, and in the import model, we see that both molecules go to the same place. Here we see an example of a sodium and potassium transporter with its ATPase. We next put it up here, and see that this transporter is able to move a molecule to a location and the other in the opposite direction. Next, we look at a transporter called "secondary transport." This is a transporter that does not consume ATP directly, but benefits from the previous consumption of ATP. In this case, glucose and sodium will enter and exit the transporter at the same location, and the glucose transporter will be called a "secondary transporter" because it does not consume ATP.
• 00:15:00 In this video, we learn about transport in cells, and how the two types of transport work differently. Primary transport, which is activated by ATP, moves molecules across the cell membrane. Secondary transport, which uses phosphate ions, uses the gradient of concentration of molecules that have already moved in a primary transport process. Here, we see sodium and glucose moving together, and then sodium and glucose associating with a protein to enter the cell. We then see the sodium and potassium potassium bomb, which is the primary transport process, and we see the degradation of the bomb as it moves across the membrane. Finally, we see the summary of the video.
• 00:20:00 The video discusses how large solid molecules, including bacteria, can be detected by macrophages, which are cells that watch for bacteria. Once bacteria are eliminated, large molecules move in and out of cells, but also may release smaller molecules that enter and exit the cell as Exposomes. Familiar terms for this process include "fagocitosis" (eating pinworms) and "ptosis" (drooping of a cell). In two cases, particular types of receptors on the cell membrane allow for uptake of specific molecules. The endocytosis process mediates uptake of molecules by specific receptors, and produces pseudopods (false tentacles). Lisosomes are organelles that digest cells, and pseudopoles may contain bacteria, viruses, or cells that have died. Finally, in a third case, large molecules are mediated by specific receptors on the cell membrane and result in pinocytosis.
• 00:25:00 In this video, we learn about water transport. Water transport is important, and we can see how it enters and leaves by looking at osmosis. Our cells need water to survive, and osmosis is the movement of water from a high concentration to a low concentration. It passes through the membrane. Remember, the membrane is a semi-member here, and there is an example. We'll see solutions and hypertonics. This depends on the solution's solute concentration. It's called a hypertonic solution if it's more dilute and a hypotonic solution if they're the same. We continue with the movement of water in the context of food intake. We'll see that water direction can be determined by the comparison of solution concentrations. I want to stop here and mention something. Water would be insolvent and the molecules in water would be called only one solution. Tonic has more absolute less water hypotonic has more solute and more water made equal. We'll see that water direction in two places: one is hypotonic and the other is hypertonic. The solutions are more concentrated and there's less water in the other place. It would be in a tonic to hypertonic transition trying to balance both
• 00:30:00 This video discusses how water moves through the body, and how concentration affects movement. It explains that blood is a solution with a high concentration of solutes outside of the body, and that this is what forms an animal's soul. Red blood cells are slowed when they cross the membrane, and this is what causes arrugated cells, dehydration, and death. Hypertonic solutions can cause both of these effects, so humans need to use isotonic solutions if they want to keep their cells healthy. Finally, the video mentions that in 2003 two scientists observed that water could move through the membrane using water purines.