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Anonymous users2024-02-07Protein is an important component (structural protein) of living organisms, and the primary structure of protein is compatible and unified with protein function.
Relationship between protein spatial structure and function: The specific spatial structure is the basis for exercising biological functions. The spatial structure determines the biological function of proteins.
Protein is the most abundant biological macromolecule in living organisms, accounting for about 45% of the solid composition of the human body, and can reach more than 70% of the dry weight of cells in cells. The content of certain tissues is higher, up to 80 in the spleen, lungs and striated muscles.
Rapidly renewing tissue cells are constantly being renewed every day. Therefore, the human body must consume a certain amount of protein every day as a raw material for the composition and replenishment of tissue cells.
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Anonymous users2024-02-06The relationship between the primary structure and function of proteins: The primary structure of proteins is compatible with and unified with protein functions. Relationship between protein spatial structure and function:
Specific spatial structures are the basis for the exercise of biological functions. The spatial structure determines the biological function of proteins.
The primary structure of protein is compatible and unified with protein function, which can be explained from the following aspects:
1) Variation of primary structure and molecular diseases.
The amino acid sequence in proteins is closely related to biological functions, and changes in primary structure often lead to changes in protein biological functions. For example, sickle cell anemia is a mutation in one of the nucleotides in the hemoglobin gene that causes glutamate at the 6th position of the -chain in the protein molecule to be replaced by valine. This nuance in the primary structure makes the patient's hemoglobin molecule prone to coagulation, causing the red blood cells to become sickle-shaped, which is prone to rupture and cause anemia, that is, the function of hemoglobin changes.
2) Primary structure and biological evolution.
Studies have found that many amino acids in homologous proteins are identical, while other amino acids are quite different. For example, comparing the primary structure of cytochrome C in different organisms, it is found that the closer the kinship with humans, the smaller the difference in amino acid composition, and the greater the difference in the kinship.
3) Activation of proteins.
In living organisms, some proteins are often synthesized in the form of precursors, and only after cleaving and removing part of the peptide chain in a certain way can they be biologically active, such as the activation of zymogen.
There is a close relationship between the spatial structure and function of proteins, and their specific spatial structure is the basis for exercising biological functions. This correlation can be illustrated in two ways.
1) Denaturation and renaturation of ribonucleases and the loss and restoration of their functions.
RNase is a polypeptide chain composed of 124 amino acids, containing four pairs of disulfide bonds, and the spatial conformation is a globular molecule. When the natural ribonuclease is treated with -mercaptoethanol in 8mol l urea, the intramolecular tetra-disulfide bond is broken, the molecule becomes a loose peptide chain, and the enzyme activity is completely lost. However, after the dialysis method was used to remove -mercaptoethanol and urea, the enzyme was oxidized and spontaneously folded into its original natural conformation, and the enzyme activity was restored.
2) Allosteric phenomena of hemoglobin.
Hemoglobin is a tetrameric protein that has oxygenating functions to transport oxygen in the blood. Studies have found that deoxygenated hemoglobin has a low affinity for oxygen and is not easily bound to oxygen. Once one subunit of the hemoglobin molecule binds to O2, it causes the conformation of the subunit to change, and causes the conformational changes of the other three subunits sequentially, making them easy to bind to oxygen, indicating that the changed conformation is most suitable for binding to oxygen.
There is no direct relationship! Look at the structure and arrangement of amino acids! Each protein has a representative amino acid!
Transcription and translation are actions, there is no diversity, they all work in the same way! The diversity of DNA here does not refer to the diversity of genes in different cells of a person, but to the diversity of DNA in one cell of a person. (i.e. the DNA on more than 40 chromosomes is not the same because the bases are arranged in a different order!) >>>More
Physiological functions of proteins: Proteins are important components of tissues and cells, such as muscles, bones and internal organs. The protoplasm of all cells is dominated by proteins, and the cell membranes and interstitium of animals are also mainly composed of proteins. >>>More
1. The following description of proteins is incorrect (d). >>>More
The protein content of most fish can reach 18 to 20 percent, which is higher than the protein content found in meat, poultry, eggs and milk, and is easily digested, absorbed, and utilized up to 85 to 90 percent. Fish protein has a complete amino acid composition, including 8 essential amino acids that cannot be synthesized by the human body. >>>More