Movement of materials:
Diffusion: this is the movement of molecules from the area of high concentration to an area where there is low concentration. Diffusion occur through cell membranes except these are freely travelable to the diffusion molecules presented that the barriers are to thin.
The emphasis of the concentration is different which is known as a concentration gradient. The diffusion rate will be much faster if the concentration gradient is greater.
There is no actual source of energy needed for diffusion of molecules.
Facilitated diffusion: material that diffuses through cell membranes by a related process is recognises as facilitated diffusion. This makes it easier for the protein channels in the cells membrane to assist in transporting molecules like urea and glucose in and out of cells.
Osmosis: this is a special type of water molecules where the movement of water molecules from a region of high concentration to a region of low concentration through a chosen permeable membrane. There is concentration gradient in osmosis but it’s only concerned with some water molecules. Selective membrane is mention here that allows some molecules to go through but not any other molecules.
Active transport: this is the movement of material alongside a concentration gradient using energy from the ATP in the cells from mitochondria. The carbohydrate digestions in the intestine which are small produce glucose which needs active transport across cells of villi in opposition to the concentration gradient.
Endocytosis: this process requires taking material that is outside the cell into the cell by pinocytosis which means cells drinking or phagocytosis which means cells eating. The region of the cell membrane fold in to the cell forming a pouch that gets narrower, which then pinches off allowing the material and the small volume of tissue to be enclosed within the cells in the membrane bound pocket. The larger particles like bacteria and the cell debris are removed this way as the endocytic vesicle move through the cell that comes together with lysosmes. The material will then be digested and broken down to raw materials.
The endocytosis can be used to bring proteins and other chemicals across cells that need to be released the other side.
The pinocytosis take in tissue fluid only and some certain molecules that the cell needs to transport the protein the membrane.
Exocytosis: this sis the process of releasing the materials from the inside in to the to the tissue fluid. The membrane vesicle moves through the cells into the cell membrane by combining with it and releasing the contents by introducing the secretary molecules into the body system. This is also a method of replacing cell membrane that is used up in the exocytosis.
Factors affecting movement:
Influences on movement of materials:
Size: the size of molecule is very important in osmosis as if its big it won’t be able to move around the body. The size of the surface is also important as if the molecules need to big enough to be moved to do its work in the cell.
Distance: the distant between the cells and material can influence the movement as if it to far apart it would be difficult to make a journey in an out, therefore it won’t have enough energy to repeat the process.
Temperature: if the temperature is to hot it can bust or kill the cells which can damage the functioning of the body.
Osmotic potential: this solution has the power to gain or loose water molecules the membrane. The weaker the solution the higher osmotic potential it has than a concentrated solution. When the tissue fluid returns to the blood the osmotic are low.
Electrochemical gradient: there different electrical across the cell membrane as the exterior cell membrane carry a positive charge and interior carry a negative charge. This is also identified as membrane potential that affects the diffusion of ions across the membrane.
Permeability of cell: the polar molecules and ions diffuse across the phospholipids bilayer in a slow pace or not diffuse at all. However the non polar molecules diffuse much quicker. Other material like lipid layer of the cell membrane, fatty acid, steroid molecules etc also diffuse in faster pace.
Concentration: high concentration during the movement can seriously damage cell when it is moving in and out due high concentration. If the low concentration movement in out can also damage the cell.
Channel proteins: there is similarity in different cell as the non polar molecules through cell membrane. Channels protein is small and fast that stops another cells from passing through and allows some ions and various protein.
Carrier molecules: there various carrier molecules that can be found in membrane, they are all particular in their own type of functioning. The amino and the sugar have their own different positions but the similarity is that they carry the same proteins.
The role of the Phospholipids Bilayer in the movement of materials in and out of the cell. d1
Phospholipids bilayer is a structure of the cell that is made up of glycerol and phosphorus. The cell membrane focuses on certain lipid compound and proteins that help the cell’s needs.
This membrane acts like a wall around the cell and keeps the intercellular molecules separated from the extra cellular surroundings. It keeps control of what enter and departs from the cell e.g. it lets in water, oxygen and glucose and let’s out are co2. The cell also supplies to the immunological identity of the cell as well as interact with nearby cell.
As the cell is a liquid like membrane a holes or damages can be repaired quickly.
Phospholipids have two very thin layers on the membrane which helps preventing proteins and ions from entering places that they shouldn’t be in. The membrane also contains a barrier. Barrier is needed to help protect the cells from getting damaged or even killed by other mistrials ions. Which is why it has barriers in and around the cells because that protects other meters from entering.
There is a function that takes place in the organelles which helps the bilayer struck its form. In normal cases when a bilayer goes in to the water it would make it self two layers and would go into a cell membrane leaving the tail of the bilayer facing the centre of the cell membrane and there won’t be almost no salt or sugar dissolving in the water. In addition the cholesterol could help in loosing many of the permeability and help it to be stronger as other molecules are not able to enter even if they want to. The membrane makes protein that is needed to for other cells to make proteins like inter cellular etc.
For the movement to take place, the cell is needed to take some important roles for the phospholipids. Without the important roles of the cell, there wouldn’t be any movement taking place due to the fact that without the important roles of the cell there can’t be any movement. The semi-permeable is helped by the phospholipids protecting the cells and insuring that the barriers of other material do not enter or exit the membrane. This helps the other organic chemicals from being produced inside the cells. Glucose is the main molecule that helps the energy movement. Glucose is the only molecule that is able to go through where as other materials like acid, oxygen, lipids, amion, water and carbon dioxide are likely to defuse in and out of the cells. Therefore the bilayer is there to allow certain molecules to go through if all molecules try to go through the wall.
Bilayer would give some of molecules from the receptors for the chemical cell for example the transmitter that is found in the human body
The water is passed from phospholipids bilayer due hydrophobic that has a tail water that does not allow the tail water to go through the molecule.
Molecules that are found in the human body are not able to go through except molecules like water, oxygen and carbon dioxide. Other than those molecules, molecules that try to go through wont be able to because for that to happen they have to go through the bilayer and then into then to cells. This process can only take place if a protein from somewhere else comes and allows them to go pass through.
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