The cells that make up the animal body are called animal cells,plant cellThey are basically the same as animal cellsnucleus、cytoplasmAnd cell membrane.But there are also differences: this is that plant cells have a thick and hard layer outside the cell membranecell wallAnimal cells have no cell wall.
The cells that make up the animal body are called animal cells. Although the cells of human or animal body have different shapes, their basic structures are the same, including cell membrane, cytoplasm and nucleus.[1]
structure
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Animal cells have nuclei, cytoplasm and cell membranes, but notcell wall，vacuoleNot obvious, containinglysosomeThe structure of animal cells includes cell membrane, cytoplasmOrganelleNucleus;Their main functions are to control the entry and exit of cells, carry out material conversion, the main place of life activities, and control the life activities of cells.There are organelles inside the cell: nucleus, double membrane, containing DNA and proteinchromosome。Endoplasmic reticulumIt is divided into rough and smooth,Rough endoplasmic reticulumRibosomes attached to the surface participate in protein synthesis and processing;Smooth endoplasmic reticulum, no surfaceribosome, participating in lipid synthesis.[2]
characteristic
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Animal cells have the following characteristics compared with microbial cells and plant cells.
① Animal cells have no cell wall, and their ability to adapt to the environment is poor.
② The volume of animal cells is thousands of times larger than that of microbial cells, slightly smaller than that of plant cells.
③ Most animal cells adhere to each other in the body in the form of clusters. In cell culture, most cells have group effect, anchorage dependence, contact inhibition and functional totipotency.[3]
cell culture
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cell cultureIt refers to the growth of cells in vitro. Animal cells no longer form tissue in the process of culture.
Concept: Take relevant tissues from animal body, disperse them into single cells, and place them in suitableculture mediumMedium, let theseCell growthAnd proliferation.
Composition of culture medium
Glucoseamino acid, inorganic salts, vitamins andAnimal serumEtc.Animal cell cultureThe key to success lies in whether animal serum is contained in the culture medium. Because there are still some components in the internal environment where animal cells live that have not been studied clearly, it is necessary to add animal serum to provide an environment similar to that in the organism. In addition, animal serum also contains some animal hormones andenzyme, can promote cell development.
1. Components of animal cell culture medium: the nutrients required for cell culture in vitro are basically the same as those in vivo, for example, sugaramino acidInorganic salts, growth promoting factors, trace elements, etc.The culture medium which is strictly prepared according to the above substances required by cells and their types and quantities is calledSynthetic medium。Since there are still some components in the internal environment where animal cells live that have not been studied clearly, it is necessary to add animal serum to provide an environment similar to that in the organism. Therefore, when using synthetic culture media, it is usually necessary to add some natural components such as serum and plasma.
①Sterile and non-toxicEnvironment: sterilize the culture medium and all culture equipment, and usually add a certain amount of antibiotics to the culture medium to prevent contamination.In addition, the culture medium should be changed regularly to remove the metabolites and prevent the accumulation of cell metabolites from harming the cells themselves.
5% CO2 gas is used to maintain the culture mediumpHstable.
4. Basic process
Take animal embryos or organs and tissues of young animals.Cut the material into pieces and useTrypsin(or withcollagen proteinEnzyme) treatment (digestion) to form dispersed single cells, and then transfer the treated cells into the culture medium to prepare a certain concentration of cell suspension.The dispersed cells in the suspension quickly adhered to the bottle wall, becoming cell adhesion.When sticking to the wallcell divisionWhen growing to contact each other, cells will stop dividing and proliferatingContact suppression。At this time, the cells with contact inhibition need to be treated with trypsin again.Then prepare a certain concentration of cell suspension.In addition, primary culture is cell and tissue culture immediately after being taken out of the body.When the cells grow and migrate out of the animals and plants, forming growth halos and increasing, scientists then carry out subculture, that is, the primary culture cells are divided into several pieces, and inoculated into several pieces of culture media, so that they can continue to grow and proliferate.Through certain selection or purification methodsCell lineThe cells with special properties obtained incell line。When cultured for more than 50 generations, most of the cells have already aged and died, but some of the cells have undergone changes in genetic material, and there is no limitpassageThe characteristic of cancer.At this timeCell integumentIt is called cell line.Adding insulin to the culture medium can promote the glucose uptake of cells.
2. The ingredients of the culture medium are different: animal serum must be used for animal cell culture,plant tissue cultureNot required.
3. Different products: plant tissue culture generally gets new plant individuals, while animal cell culture generally fails to express itsOmnipotenceSo we get the same kind of cells.
4. Different principles: the principle of plant tissue culture is the totipotency of plant cells, and the principle of animal cell culture is cell proliferation.
5. Different processes: the process of plant tissue culture is dedifferentiation and redifferentiation, and the process of animal cell culture is primary culture and subculture.
The cells that make up an animal body are called animal cells. Although various cells of human body or animal body have different shapes, their basic structures are the same, with cell membrane, cytoplasm and nucleus in their parts.
Primary cells refer to cells cultured immediately after being taken out of the body.
Adaptation continues under in vitro culture conditionsSubcultureThe cells of.
Generally, the animal cells cultured in large quantities in vitro areMammalian cell、insect cell、Avian cellandFish cellEtc.
Animal cells have cell membrane, cytoplasm and nucleus.The cytoplasm of animal cells includesCytoplasmic matrixAnd organelles.Not in animal cellscell wall, onlyplant cellyes.
The cell membrane is a membrane composed of protein molecules and phospholipid bilayer molecules. Small molecules such as water and oxygen can pass through freely, while some ions andmacromoleculeMaterials cannot pass through freely. Therefore, in addition to protecting the inside of cells, it also has the function of controlling the ingress and egress of substances: it neither allows useful substances to seep out of cells arbitrarily, nor allows harmful substances to enter cells easily.
Cell membraneoptical microscopeIt is difficult to distinguish.useelectron microscopeObservation shows that cell membrane is mainly composed of protein molecules and lipid molecules.In the middle of the cell membranePhospholipid bilayerThis is the basic skeleton of cell membrane.On the outside and inside of the phospholipid bilayer, there are many spherical protein molecules, which are embedded in the phospholipid molecular layer at different depths or covered on the surface of the phospholipid molecular layer.Most of these phospholipid molecules and protein molecules can flow, which can be said that the cell membrane has a certain fluidity.This structural feature of cell membrane is very important for it to complete various physiological functions.
