Company name: Ladd Porter (Beijing) Biotechnology Co., Ltd.
Contact: Zhang Wei
Mobile phone: 18101288748
Address: room 2071, 2 floor, 5 building, No. 5 hospital, Beijing, Chaoyang District.
Cells are an important part of life, cell research has made a great breakthrough today, people have a deeper understanding of cells, we know that biological diversity also represents the diversity of cell types, Jinan Cell Engineering brings you to look at the types of cells and cells. The way of operation.
Biology classified as bacteria, fungi, and plants consists of cells with a cell wall, whereas protozoa has some organisms with this structure, but animals do not.The main component of plant cell walls is cellulose, which is formed through systematic weaving to form a reticular outer wall. It can be divided into middle glue layer, primary cell wall and secondary cell wall. The mesocarp is the first spacer formed between the newly divided daughter cells of a plant cell, consisting mainly of pectin (a polysaccharide), followed by the formation of a primary cell wall on both sides of the mesocarp. The primary cell wall consists mainly of pectin, lignin and a small amount of protein. The secondary cell wall is mainly composed of fibers arranged by cellulose, like a line arranged at a right angle, and then bonded by lignin and other sugars.Living cells
The cell wall of fungi is composed of chitin, cellulose and other polysaccharides, in which chitin contains carbohydrates and ammonia, soft, elastic, mixed with calcium salt hardening, forming the exoskeleton of arthropods. Chitin is insoluble in water, alcohol, weak acid and weak alkali. It has protective function.
The inner wall of the cell wall is tightly attached to a very thin membrane called Cell Membrane. This layer consists of protein molecules and phospholipid bilayers. Small molecules such as water and oxygen can pass through freely, while some ions and macromolecules can not. Therefore, in addition to protecting the inner part of the cell, it also has the function of controlling the entry and exit of substances into the cell: neither allowing useful substances to seep out of the cell at will, nor allowing harmful substances to enter the cell easily. In addition, it can exchange information between cells.
The cell membrane is not easy to distinguish under optical microscope. By electron microscopy, we can know that the cell membrane is mainly composed of protein molecules and lipid molecules. In the middle of the cell membrane is the phospholipid bilayer, which is the basic framework of cell membrane. On the outside and inside of the phospholipid bilayer, there are many spherical protein molecules, which are embedded in the phospholipid bilayer at different depths or coated on the surface of the phospholipid bilayer. Most of these phospholipid and protein molecules are mobile, so to speak, cell membrane has a certain fluidity. This structural feature of cell membrane is very important for its various physiological functions.
The way of transmembrane transport is divided into two types: passive transportation and active transportation.
Passive transport is diffusion along the concentration gradient on both sides of the membrane, from high concentration to low concentration. Divided into free diffusion and assisted diffusion.
Free diffusion: substances enter cells through simple diffusion. Differential concentrations on both sides of the cell membrane and the properties of diffusive substances (e.g. liposoluble substances are more likely to enter and leave the cell according to the principle of similar solubility) have an effect on the rate of free diffusion. Common substances that can diffuse freely include oxygen, carbon dioxide, glycerol, ethanol, benzene, urea, cholesterol, water, ammonia, etc.
Assist diffusion: substances that enter and store cells are diffused with carrier proteins. The concentration difference on both sides of the cell membrane and the type and number of carriers affect the rate of diffusion. The absorption of glucose by red blood cells is assisted by diffusion.
The thick, transparent substance wrapped in cell membranes is called cytoplasm (Cytoplasm). In the cytoplasm can also see some refractive particles, most of these particles have a certain structure and function, similar to various organs of organisms, so called organelles. For example, in the mesophyll cells of green plants, you can see many green particles, which are organelles called chloroplasts. Photosynthesis of green plants is carried out in chloroplasts. In the cytoplasm, one or more vacuoles can often be seen, which are filled with liquid, called cell fluid. In mature plant cells, vacuoles merge into a large central vacuole, which accounts for most of the cell volume. The cytoplasm is compressed into one layer. The cytoplasm between cell membrane, vacuole and two layers of membrane is called protoplasm.
The protoplast of plant cells is equivalent to a layer of semipermeable membrane. When the cell solution concentration is lower than the outside concentration, the water in the cell solution enters the outside solution through the protoplasm layer, causing the cell wall and protoplasm layer to contract to a certain extent. Because the protoplast is more flexible than the cell wall, when the cell is constantly dehydrated, the protoplast layer and cell wall separation, that is, plasmolysis. When the concentration of the cell solution is higher than that of the external solution, the water in the external solution enters the cytoplasm through the protoplasm layer to restore the protoplasm layer, and the recovery of the plasmolysis gradually takes place.
The cytoplasm is not stationary but moving slowly. In a cell with only one central vacuole, the cytoplasm often circulates around the vacuole, thus facilitating the transport of intracellular material and strengthening the interconnection between organelles. Cytoplasmic movement is a life phenomenon that consumes energy. The more vigorous the cell activity is, the faster the cytoplasmic flow is, whereas the slower it is. After cell death, the movement of cytoplasm also stops.
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Address: Ladd Porter (Beijing) Biotechnology Co., Ltd.
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