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Animal cell structures include cell membrane, cytoplasm, and nucleus. The cytoplasm of animal cells includes the cytoplasmic matrix and organelles. The organelles of animal cells include endoplasmic reticulum, mitochondria, Golgi apparatus, ribosomes, lysosomes, centrosomes.
The outermost part of an animal cell is the cell membrane and has no cell wall; Animal cells do not contain chloroplasts in their cytoplasm and do not form vacuoles. Whereas, higher plant cells do not have centrosomes.
According to their basic structure, cells can be divided into two categories, one is prokaryotic cells and the other is eukaryotic cells. Protocells refer to the cells that make up lower organisms such as bacteria and cyanobacteria, which are relatively primitive, evolutionarily inferior, and relatively simple in structure, without typical nuclei and organelles. Eukaryotic cells differ from prokaryotic cells in that they have a distinct nuclear structure and various organelles.
Its structure is much more complex than that of prokaryotic cells, consisting of three basic parts: the cell membrane, the cytoplasm, and the nucleus. The vast majority of the more than 1.5 million living organisms are made up of eukaryotic cells. The six elements of carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur are the main elements that make up the protoplasm of cells.
The organic matter that makes up the cell generally refers to a general term for carbonaceous compounds or hydrocarbons and their derivatives. Organic compounds composed of carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus, etc. Sugars, fats, proteins, and nucleic acids are the most important organic compounds in living organisms and the most important organic compounds in cells." Cells are the basic unit of structure and function of all living organisms, and the size and morphology of human cells have a great relationship with their environment and function.
The structure of a cell mainly consists of three parts: the cell membrane, the cytoplasm, and the nucleus. When cells are observed under an electron microscope, they can be distinguished into membrane-phase structures and non-membrane-phase structures. The cell membrane is a thin film on the surface of the cell, its thickness is about nanometers, and the chemical composition of the cell membrane is mainly lipids, proteins, and a certain amount of sugars.
Under the electron microscope, the cell membrane can be seen that its structure is divided into three layers, the inner and outer layers are dark and dark, and the middle layer is light. Also, cytoplasm is the part between the cell membrane and the nucleus, including the organelles and the matrix.
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The basic elements that make up cells are: O, C, H, N, SI, K, CA, P, MG, of which O, C, H, and N account for more than 90%. Cellular chemicals can be divided into two main categories:
Inorganic and organic. Among the inorganic substances, water is the most important component, accounting for about 75% to 80% of the total content of cellular matter.
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Blood is made up of two parts: blood cells and plasma. Blood cells include red blood cells, white blood cells, and platelets. Plasma includes: water,
Plasma proteins. albumin, globulin, and.
Fibrin. element), inorganic salts (Na+, K+, Ca++, Mg++, Cl-, etc.), non-protein organic compounds (amino acids, urea, uric acid, creatinine, glucose, lipids), etc.
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a.Plasma. Blood is made up of four components:
Plasma, red blood cells, white blood cells, platelets. Plasma makes up about 55% of blood and is a mixture of water, sugar, fat, protein, potassium and calcium salts. It also contains many of the chemicals necessary for blood clot formation to stop bleeding.
Blood cells and platelets make up the other 45% of blood
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The main component in the cell is water.
Substances in cells: in terms of type and function.
Inorganics: The molecules are relatively small, generally do not contain carbon, inorganic salts, and the constituent substances of cells, which affect the life activities of cells, such as NaCl, etc. Water :
The most abundant substances in cells, are good solvents, provide a place for metabolism Organic matter : the molecule is relatively large, generally containing carbon, carbohydrates : provide energy for the life activities of cells, such as starch, glucose, etc.
Protein : the most abundant organic matter in the cell, an important constituent substance, with a variety of functions, such as hemoglobin, which transports O2 lipids and stores the most energy, has a supportive and protective effect. In addition, animal fats also have a thermal insulation effect > nucleic acids:
Mainly distributed in the nucleus of the cell, it has a genetic role The cell membrane controls the entry and exit of substances: the cell membrane separates the inside of the cell from the environment outside the cell, which has a protective effect, so that the internal environment of the cell maintains relative stability and maintains its normal life activities. In addition, the cell membrane also has a certain selectivity.
It allows substances useful for cell life activities to enter, blocks other substances from the outside of the cell, and at the same time excretes waste products produced in the cell to the outside of the cell.
cell: There is no universal definition of cell, the more common reference is:
Cells are the basic structural and functional units of living organisms. It is known that all organisms except viruses are composed of cells, but the life activities of viruses must also be reflected in cells. Generally speaking, most microorganisms such as bacteria and protozoa are composed of a single cell, that is, single-celled organisms, while higher plants and higher animals are multicellular organisms.
Cells can be divided into two categories: prokaryotic cells and eukaryotic cells, but some people have proposed that they should be divided into three categories, that is, the ancient karyotic cells that originally belonged to prokaryotic cells should be separated as a parallel category. The discipline that studies cells is called cell biology. Cells are so small that they can only be seen under a microscope and come in a variety of shapes.
It is mainly composed of the nucleus and cytoplasm, and has a cell membrane on the surface. Higher plants have a cell wall outside the cell membrane, plastids in the cytoplasm, chloroplasts and vacuoles in the body, and mitochondria. Animal cells do not have a cell wall, and centrosomes are often present in the cytoplasm, while higher plant cells do not.
Cells have functions such as locomotion, nutrition, and reproduction.
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The compounds that make up the cell of water can be roughly divided into: inorganic compounds and organic compounds Inorganic compounds: including water and inorganic salts; Organic compounds:
Including proteins, nucleic acids, sugars and lipids Water: 80%-90%, inorganic salts: 1%, protein:
7%--10%, lipids: 1%--2% Carbohydrates and nucleic acids: 1%, so it can be seen that the most abundant component of the cell is water.
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Cell membrane, cell wall, nucleus. There is intracellular fluid in the cell.
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The fresh is the water, and the dried is the protein.
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