What does the metabolic process of protein look like in the human body?

Do you understand the metabolism of proteins in the human body.

(1) The starting part of the human body to decompose starch is the oral cavity; The starting point of protein breakdown in the human body is the stomach (2) The organ that secretes pancreatic juice is the pancreas, which contains enzymes that digest starch, fat, and protein, and the pancreatic juice flows into the duodenum through the ducts

3) Ming Ming ate fried dough sticks and soy milk in the morning, the fat substances contained in the fritters need to be secreted by the liver to make the fat into tiny particles, thereby increasing the contact area between lipase and fat, which plays a role in promoting fat decomposition, and the fat is finally decomposed into glycerol and fatty acids

4) The main organ of the human body that absorbs nutrients is the small intestine

So the answer is: (1) ; Oral cavity; ②；Stomach;

2）③；Pancreas; Starch; Fat; Protein;

3）④；Liver; Bile; Glycerol; Fatty acid;

4）⑤；Small intestine;

Answer]: Under normal circumstances, the body's proteogenesis are in dynamic equilibrium, and tissue proteins and some nitrogen-containing compounds are constantly decomposed and synthesized. The protein ingested from food is digested and absorbed into the body, and a part of it is used in the liver for the synthesis of white matter or the decomposition of amino acids, and the other part is distributed to various tissues and organs of the body with the blood.

In tissues, amino acids synthesize tissue proteins, enzymes and hormones on the one hand, and decompose into keto acids and ammonia on the other. These synthesis and decomposition are generally reversible reactions and constitute a dynamic equilibrium, so that the amount of amino acids in the blood can be kept constant.

The end products of protein catabolism in the body are:

a.Amino acid.

b.Peptides. c.Carbon dioxide, water, urea.

d.Amino acids, amines, reflux uric acid.

e.Creatinine and creatine leak hail.

Correct answer: c

Categories: Life.

Problem description: There is a problem like this, the metabolic intermediate products or final products of fats, sugars, and proteins are all acidic substances, and now the following substances, which of them are derived from fats, sugars, and proteins?

Five: phosphoric acid, sulfuric acid, uric acid, glyceric acid, carbon dioxide?

Analysis: Fat-glycerate carbon dioxide.

Sugars - carbon dioxide.

Proteins - phosphoric acid, sulfuric acid, uric acid, carbon dioxide.

The final decomposition of sugars into carbon dioxide and water.

Proteins can eventually be broken down into proteins, which can eventually be broken down into carbon dioxide, water, urea, and provide energy for the human body, and some proteins can also be converted into organic amines, and can also be converted into other nitrogen-containing compounds.

The metabolic end product of sugars is carbon dioxide and water.

The metabolic end product of protein is urea.

The end products of the metabolism of all organic matter in the body, that is, the products of complete metabolism, are carbon dioxide and water!

Protein metabolism: In addition to synthesizing the proteins it needs, the liver also synthesizes albumin, partial globulin, fibrinogen, prothrombin and coagulation factors. When the liver is severely damaged, the albumin synthesized mainly in the liver is significantly reduced and globulin can be increased, the albumin ratio decreases and becomes inverted, and edema or ascites often occurs when the albumin content in 100 ml of blood is less than a gram.

Hepatocytes contain a variety of enzymes related to protein amino acid metabolism, especially the activity of glutamate-propylene aminotransferase is significantly higher than that of other tissues, and when liver lesions occur, the activity of this enzyme can be increased, that is, the rapid aminotransferase is increased. After the protein is digested, various amino acids are synthesized, and the liver can turn the amino acids into ammonia, which is further excreted from the urine according to the synthetic urea. Ammonia is a toxic substance, and if the liver is severely damaged, the liver's ability to remove ammonia is reduced, and the ammonia content in the blood is too high, which leads to ammonia poisoning coma, which is hepatic encephalopathy.

The liver plays an important role in protein synthesis and catabolism In addition to synthesizing various proteins required by the liver itself, it also synthesizes plasma albumin, fibrinogen and prothrombin Some A globulins and B globulins in plasma are also synthesized by hepatocytes, and only Y globulin is mainly synthesized by plasma cells The protein content in normal human serum is 6 0 7 5 g 100 ml serum, albumin A4 0 5 5 g 100 ml serum, globulin G2 0 3 0 g 100 ml serum, the ratio of albumin to globulin is 1 5 2 5 5 In liver lesions, the synthesis of albumin is mainly reduced In acute hepatitis, due to the short course of the disease, the change of serum albumin is not obvious; In chronic hepatitis or cirrhosis, serum albumin is significantly reduced, while Y-globulin is significantly increased, and the total serum protein content is often reduced The A-g ratio becomes smaller, or even less than 1, this phenomenon is called A-G ratio inversion The molecular weight of B-globulin and Y-globulin in the serum is larger, the isoelectric point is higher, the surface charge is less, and it is easy to produce turbidity or flocculent agglutination reaction with zinc sulfate, thymol and cerebral phospholipid cholesterol; The albumin and A1 globulin have a smaller molecular weight, a lower isoelectric point, and more surface charge, which have the effect of preventing the above-mentioned turbidity or flocculent agglutination reaction This is the theoretical basis for the commonly used clinical examination of liver function and various turbidity or flocculent tests Hepatocytes contain many enzymes related to amino acid metabolism, so the amino acid metabolism of the liver is very active, such as the transamino, dehydrogenation and decarboxylation of amino acids, etc., can be carried out in the liver The transaminase activity of the liver is high, especially the valley Alanine aminotransferase activity is significantly higher than that of other tissues When liver function is impaired, the serum glutaminase SGPT activity is increased due to the increased release of enzymes in liver cells, so the measurement of SGPT activity is helpful for the diagnosis of liver diseases The liver is also an important organ for processing amino acid metabolites All kinds of ** ammonia can synthesize urea in the liver through the ornithine cycle When liver function is severely impaired, blood ammonia concentration can increase due to the reduced ability to synthesize urea This is one of the causes of hepatic encephalopathy

It is mainly manifested by changes in the content of plasma proteins.

Plasma proteins mainly include albumin, globulin, fibrinogen, and trace amounts of enzymes and zymogen (such as prothrombin). The total amount of plasma protein in a normal human is 6 g%, of which albumin grams, globulin 3 grams, fibrinogen grams, albumin The ratio of globulin is.

1.Decreased plasma albuminPlasma albumin is synthesized by hepatocytes, and when hepatocytes are damaged, plasma albumin decreases. The liver synthesizes albumin about 12 18 grams per day, and the half-life is about days, so in acute hepatitis in the short term, the changes in plasma albumin are not obvious.

Hepatocytes are severely damaged (acute or chronic), such as acute or subacute hepatic necrosis, chronic hepatitis, hepatic hard rock cryptography, etc., and plasma albumin is significantly reduced due to decreased albumin synthesis. Decreased plasma albumin (less than gram %), plasma colloidal osmolality, is one of the important causes of ascites or generalized edema.

2.Coagulation substances such as fibrinogen and prothrombin reduce fibrinogen, prothrombin and coagulation factors, which are synthesized in hepatocytes. Severe damage to hepatocytes, decreased production of coagulation factors, and decreased blood coagulability are important causes of bleeding tendency in patients with liver disease.

3.Globulinia, mainly -globulin. Globulins are produced by plasma cells.

In liver disease, the production of -globulin increases due to antigen stimulation. -Globulin is synthesized by hepatocytes, plasma cells, lymphocytes, and its main component is -lipoprotein. In liver disease, -globulin is often increased, especially in cholestasis, such as in patients with obstructive jaundice, and the blood socks sell -globulin is significantly elevated, which may be related to lipid metabolism disorders.

In liver disease, globulin increases due to decreased albumin synthesis. Thus, although total plasma protein may not change significantly, the albumin-globulin ratio is reduced and can be smaller than or even inverted (i.e., more globulin than albumin).