1. Long-term exercise makes your body sour. Reason: Glucose and other nutrients decompose and metabolize to produce lactic acid. The accumulation of lactic acid makes muscles sour and will decompose after a certain period of time. 2. The reason why the fish surfaced on cloudy days: the cloudy weather is low, the dissolved oxygen in the water is low, and the oxygen on the water surface is relatively high. 3. The reason why the earthworm crawled out of the soil after the rain: After the rain, the oxygen in the soil was squeezed out by water, and the earthworm crawled out of the ground to breathe oxygen. But many will not be dried in the soil in time, trampled to death and so on. 4. Sugar water mixed with tomatoes is actually the least nutritious reason: the osmotic pressure of sugar water is large, and the last juice is tomato cell juice, mostly water. 5. The reason for leaving more lateral roots when cutting plants is to increase water absorption and improve survival rate. 6. The reason why the newly transplanted plants leave few leaves: too many leaves have strong transpiration, while the roots of the newly transplanted plants are destroyed and the water absorption is still weak. Too many leaves will make them die of lack of water. 7. Fruits and vegetables are best soaked before eating. Reason: Soaking in bubbles can make the pesticides on the surface dissolve in water, but the time should not be too long, otherwise it will be absorbed. 8. Put salt before wrapping Chinese cabbage buns. Reason: Chinese cabbage cells will leave the plasma wall when exposed to salt, and it is not easy to wrap the cell fluid. 9. Add salt when cooking jiaozi. Reason: It can prevent adhesion. 10. Reason: Flowers often loosen the soil.
2. Microbiological knowledge
Microorganisms refer to all tiny organisms that are invisible or unclear to the naked eye, so they need to be observed with a microscope.
Microorganisms include prokaryotes (such as bacteria), eukaryotes (such as fungi, algae and protozoa) and acellular organisms (such as viruses). The main characteristics of microorganisms are not only small in size, but also simple in structure.
Because microorganisms are tiny in activity, large in relative area and fast in substance absorption and transformation. The growth and reproduction of microorganisms are also very rapid and have strong adaptability.
From cold glaciers to extremely hot hot springs, from extremely high mountain tops to extremely deep seabed, microorganisms can survive. Because of the strong adaptability of microorganisms, it is easy to accumulate a large number of individuals in a short time (for example, 10 10 /ml), so it is easy to screen and isolate mutant strains.
The characteristics of microbial mutants are easy to obtain, which brings broad opportunities for human beings to use and develop microorganisms, but it is also the internal cause of drug resistance. Metabolism of microorganisms The metabolism of microorganisms refers to all chemical reactions that occur in microorganisms (cells).
The metabolism of microorganisms is extremely vigorous, because the ratio of surface area to volume of microorganisms is very large (about 300,000 times that of adults with the same weight), which enables them to exchange substances with the external environment quickly. Metabolite microorganisms will produce a variety of metabolites during metabolism.
According to the relationship between metabolites and microbial growth and reproduction, it can be divided into primary metabolites and secondary metabolites. Primary metabolites refer to substances produced by microorganisms through metabolic activities and necessary for their own growth and reproduction, such as amino acids, nucleotides, polysaccharides, lipids and vitamins.
The types of primary metabolites in different kinds of microbial cells are basically the same. Secondary metabolites refer to complex chemical structures produced when microorganisms grow to a certain stage, which have no obvious physiological function to microorganisms, or are not necessary substances for microbial growth and reproduction, such as antibiotics, toxins, hormones, pigments, etc.
Different kinds of microorganisms produce different secondary metabolites, which may accumulate in cells or be discharged into the external environment. Metabolic regulation microorganisms have formed a complete metabolic regulation system in the long-term evolution process to ensure that metabolic activities are carried out economically and efficiently.
There are two main ways to regulate microbial metabolism: the regulation of enzyme synthesis and the regulation of enzyme activity. In addition, artificial measures to control microbial metabolism include changing the genetic characteristics of microorganisms and controlling various conditions in the production process.
The main classified microorganisms are mainly divided into the following categories: (see biological taxonomy) Prokaryotes, bacteria, archaea, eukaryotes, fungi, protozoa, algae, acellular biological viruses, viroids, viroids, prions (also known as prions). Protein infectious particles (prions) [Editor] The existence of microorganisms in nature. Microorganisms widely exist in nature, and the number is huge. The following table is an estimate of the number of microbial cells in some ecological environments: the global total density is108 ~109l-1,about 1029, and the marine sediments are 109 g- 1, about 3*. 1029 animal digestive tract101g-1about 1025 deep about 102~ 108 about/kloc-0.
[Editor] The role of microorganisms is closely related to human production, life and survival. Many foods (such as soy sauce, vinegar, monosodium glutamate, wine, yogurt, cheese and mushrooms), industrial products (such as leather, textiles and petrochemical products) and medicines (such as antibiotics, vaccines, vitamins and ecological pesticides) are made of microorganisms. Microbes also play an important role in mineral exploration and mining, waste treatment (such as water purification, biogas fermentation) and other fields.
Microorganisms are the only known nitrogen-fixing bacteria (such as soybean rhizobia) and animal and plant residue degrading bacteria (such as cellulose degrading bacteria) in nature. They are located at both ends of the common biological chain, thus completing the connection of biomass such as carbon, nitrogen, sulfur and phosphorus in the great cycle. Without microorganisms, many living things would lose their necessary sources of nutrition, and the fiber residues of plants would not be decomposed and accumulated indefinitely, so there would be no prosperity and order in nature today, and there would be no emergence and maintenance of human beings.
In addition, microorganisms also play an important role in the global climate change. Many microorganisms directly participate in the emission or absorption of greenhouse gases, and many microorganisms can become future biofuels [1].
[Editor] Microorganisms are closely related to human health. Most microorganisms are harmless to human body.
In fact, there are many normal and beneficial flora living on the outer surface (such as skin) and inner surface (such as intestine) of human body. They occupy these surfaces, produce natural antibiotics and inhibit the landing and growth of harmful bacteria; They also help to absorb or make some essential nutrients, such as vitamins and amino acids.
The imbalance of these flora (such as antibiotic abuse) can lead to infection or nutritional deficiency. On the other hand, however, many diseases of human beings, animals and plants are also caused by microorganisms, which are called pathogenic microorganisms or pathogens.
The following table lists the important human pathogenic microorganisms. Names of main human pathogenic microbial diseases: the number of pathogens infected (carried) worldwide, the number of new cases and the number of deaths each year ~ 2 billion (accounting for one third of the global population), 88 1 10,000 cases (2003 [1]) and1750,000 people (2003 [ 365,654.38+100,000 people, hepatitis B virus 6,543.8+100,000-30,000 people, measles virus 30,000 cases, 900,000 people, dengue virus 20,000 cases, influenza virus, almost all the population, 3. 00-5 million cases of yellow fever, 250,000 cases of yellow fever virus, 200,000 cases of yellow fever virus, and 30,000 cases of yellow fever virus. Other commonly heard pathogenic microorganisms are: smallpox virus (causing smallpox) and poliovirus (causing polio); Bacillus anthracis causing anthrax; And the SARS coronavirus that appeared in recent years (causing severe acute respiratory syndrome, also known as SARS, also known as atypical pneumonia).
3. Knowledge about bacteria
Bacteria are the largest and most diverse groups in the microbial world. They belong to prokaryotes, including Spirillum, Vibrio, Spirulina, Actinomycetes, Bacillus, Coccus, Mycoplasma and Rickettsia.
Actinomycetes are organisms between bacteria and mold, which are gram-positive, but their morphology is similar to mold. Spirillum is between protozoa and bacteria, but protozoa belongs to longitudinal reproduction, while spirochetes belong to transverse division reproduction; However, the cell wall of this strain lacks firmness, which is the biggest difference from Spirillum. Some bacteria, such as Vibrio cholerae, Salmonella, Staphylococcus aureus, etc. Once it enters the human body, it will make us sick, but some bacteria parasitic in our intestines, such as Lactobacillus bifidus or some lactic acid bacteria, can help us keep healthy. Antibiotics are a magical substance produced by actinomycetes, which can help us fight bacteria and reduce the mortality rate of diseases.
In addition to medical uses, microorganisms also play the role of decomposers in the environment. They can circulate fixed nutrients in the biosphere and make nutrients flow in different organisms. At the same time, it also helps us decompose toxic substances in the environment, so that the polluted environment can be reused by us; But they also produce some greenhouse gases, causing environmental damage. Bacteria are also used in food to produce some dairy products, such as cheese and yogurt. Bacteria are single-celled organisms belonging to prokaryotic cells, with small size and simple structure. There is no nucleus, nucleoli and nuclear membrane formed, and there are no other organelles except white blood cells. It has a relatively stable shape and structure under suitable conditions. Generally, the morphological characteristics of various bacteria can be identified by observing them with an optical microscope, but the internal ultrastructure can only be seen with an electron microscope. The morphology of bacteria is of great theoretical and practical significance to the diagnosis and prevention of diseases and the study of bacteria.
Bacteria are generally spherical, rod-shaped or spiral prokaryotes, which usually reproduce in binary division. Bacteria are very small. Generally, the diameter of cocci is 0.5~ 1.0 micron, the width of bacilli is 1 micron, and the length is 2 microns. Bacteria are widely distributed in nature, which exists in soil, water, air, animal and plant surfaces and digestive tract. Soil is the main distribution place of bacteria, and each gram of dry soil contains about 10 to 10 times of bacteria. Most bacteria are heterotrophic, and a few are autotrophic, including chemoautotrophic and photoautotrophic. Most heterotrophic bacteria are saprophytic and a few are parasitic.
4. Ten biological tips for human body
1: The circumference of two fists is the circumference of the neck.
The length of seven feet is the height of the body. 3. The heartbeat is 2.5 billion to 3 billion times in a lifetime.
4: Swallow saliva about 580 times a day. 5. People will die if they don't sleep for 0/0 day.
6. People lack inspiration in the afternoon, are smarter at night and are more creative when taking a shower. 7: People's left and right nostrils breathe once every three hours, and they only know when they catch a cold.
8. Muscle can be the engine of human body. 9: Insulin that helps digestion is active in the morning, so be sure to have breakfast.
10: Finger flexion and extension 2500 times in a lifetime. 1 1: The average person urinates every year 12 hours.
12: The length of the intestine is 4-5 times of the height. 13: It only takes 20 seconds for blood to circulate once a week.
14: The length of blood vessels can circle the earth twice. 15: The human brain remembers a computer with a capacity of 4G.
16: People's sleep cycle is 90 minutes, and staying in bed for 30 minutes will enter the next cycle. 17: Most of the natural delivery time is from 5 pm to 6 pm, and more than 60% are delivered around 6 pm.
18: At six o'clock in the afternoon, the human body's secretion of adrenaline reached its peak, and at this time it was most capable of coping with difficulties. 19: The left ear is controlled by the right brain, which dominates emotions, so the left ear is more agile than the right ear when receiving sweet words.
20. The original division of labor makes women's vision almost six times that of men. Men like to stare at a goal, and their horizons are farther, but they are not as broad as women's. 2 1: People share the same brain area in sex color, money and delicious chocolate, which makes people influenced by sex color in money choice and take risks in a much larger proportion.
22: Intelligence is slower than physical aging. 23: Exercise at night. At this time, people's taste, vision and hearing are more sensitive, their coordination ability is stronger, and their heart rhythm and blood pressure are relatively stable.
The number of heartbeats is a fixed number in a person's life. 25: People are resourceful when dealing with negative information that flashes in the subconscious, such as danger, despair, violence, etc.
26: People can fall asleep in an average of 7 minutes. 27: I can't keep my eyes open when sneezing.
28: The brain is more active when sleeping than when watching TV. 29: The fingernails of the thumb are the slowest and the fingernails of the middle finger are the fastest.
Sleeping consumes more calories than watching TV. 3 1: The eyes were big when they were born, and they are still big now, but the nose fish's ears have been growing.
32: The tongue has ten thousand taste buds. Right-handed people live nine years longer than left-handed people.
Tongue prints are the same as fingerprints, and everyone is different. If the moon is directly above people, people will be thinner.
People use the bathroom six times a day on average. Every square inch of human skin contains 20 feet of blood vessels.
38: There are 360 bones at birth and only 206 bones in adulthood. 39: Beard is the fastest growing human hair. If you don't transform it, you can grow 30 feet in your life.
40: When sneezing. The human heart will stop beating about 1 millisecond.
4 1: Right-handed people can live about nine years longer than left-handed people. The maximum noise that people can tolerate is: 1.20 dB. What is the sound that people can hear? Hertz: 20-20000 Hertz. The hearing range of human ear is: 20hz-20000Hz. What is the highest value of the frequency range of sound waves that people can generally hear? Hertz: 20-20000 Hertz. The human brain needs to be mature: 3 years of saliva: when the food eaten by weakly acidic people passes through the digestive tract, where does it stay the longest? The bile of colon people is: in which part of the brain is the logical thinking activity of yellow people carried out? Where does the salty taste in the tears of left-brained people come from? How does the sense of smell in blood change with age? Which part of the tongue is most sensitive to sweetness? The reason why people on the tip of the tongue sweat during exercise is to keep their body temperature normal. When breathing, the lungs are: How deep can a passive stretching person dive? 30 meters has 42 facial expression muscles. When we smile, how many muscles are activated first: 4 people * * * How many pairs of ribs: 12 What are the joints with the largest range of motion? Shoulder joint When did the first heartbeat of the human body start? At the third week of embryo development, the most distributed sweat glands are-:palms and soles. Where is the human skin most sensitive? Fingertips What is the longest organ in the human digestive tract? What is the longest organ in the small intestine? What is the largest endocrine gland in the small intestine? What is the percentage of muscle tissue in thyroid people? 1/ The hardest substance in the human body is enamel. The organ that catabolizes alcohol is the liver. The internal organs of human detoxification are: the liver. What is the biggest detoxification organ? What is the thickest blood vessel in the human body? What is the organ that can tolerate hypoxia best? What is the largest cell in the brain? What is the smallest organ in the human body? What is the biggest muscle in the human body? What is gluteus maximus? What is the smallest muscle in the human body? Stapes muscle The largest digestive gland in the human body is: the liver and the five internal organs. Gallbladder, small intestine, stomach, large intestine and bladder, which of the following groups belongs to the five internal organs? The first aging organ in the human body is: How many muscles does the thymus have? How long is the small intestine of more than 600? How many kinds of blood vessels are there in the human body? How many pairs of cranial nerves do three kinds of human bodies have? How many bones does the human body have? There are three types of human muscles. Gastrointestinal peristalsis, respiration, circulation and other activities depend on: smooth muscle. The main component of gastric acid in human body is: which element is lacking in hydrochloric acid will cause goiter. Iodine What is the most important organ in human body? The organ with the highest percentage of water content in the liver is the eyeball. The human body can conduct electricity because it contains water. The safe voltage of the human body is 36V. How many sex chromosomes does the human body have: 1? The development of the human body begins with a cell.
5. What are the applications of microorganisms in daily life?
If you drink yogurt, you will drink a lot of lactic acid bacteria. Wine is also brewed by microorganisms. There are also soy sauce, vinegar, soy sauce: the conventional food of northerners, as well as stinky tofu, tofu brain and so on. Do you usually steam steamed bread? If you steam, you should use yeast. Microbes are closely related to people, but you just don't notice them. Most of the above is food. Tell me about others. In modern biopharmaceuticals, anti-inflammatory drugs are probably made of microorganisms. The fuel used in cars is alcohol, which is usually fermented by microorganisms. There are a lot of normal flora in human intestine. Once they are confused, you will get sick. In short, places related to microorganisms.
6. What microorganisms are there?
Microorganisms refer to those biological groups whose individual volume and diameter are generally less than 65438±0mm, and their structures are simple, mostly single cells, and some even have no cell structure.
People usually use microscopes or electron microscopes to see their shapes and structures clearly. It should be noted that microorganism is a relatively general concept, and the boundaries are sometimes very vague.
For example, unicellular algae and some protozoa should also be considered microorganisms, but they are usually not studied in microorganisms. According to the classification proposed by Chinese scholars, organisms are divided into six kingdoms: virus kingdom, monera kingdom, protozoa kingdom, fungi kingdom, plant kingdom and animal kingdom.
It is not difficult to see that microorganisms occupy four of the six realms, so the important position of microorganisms in nature is obvious, and its research objects are also very extensive and rich. Microbes are a group of microorganisms widely existing in nature, which are invisible to the naked eye and must be magnified hundreds, thousands or even tens of thousands times by optical microscope or electron microscope.
They have the advantages of small size, simple structure, fast reproduction, easy variation and strong adaptability to the environment. There are many kinds of microorganisms, at least more than100000.
According to their differences in structure, chemical composition and living habits, they can be divided into three categories. 1. Eukaryotic microorganisms have a high degree of nuclear differentiation, including nuclear membranes, nucleoli and chromosomes; There are complete organelles (such as endoplasmic reticulum, ribosome and mitochondria) in cytoplasm.
Fungi belong to this kind of microorganisms. Second, the degree of nuclear differentiation of prokaryotic microorganisms is low, with only the original nucleoplasm, no nuclear membrane and nucleoli; The organelles are not perfect.
There are many kinds of such microorganisms, including bacteria, spirochetes, mycoplasma, rickettsia, chlamydia and actinomycetes. 3. Cell-free microorganisms have no typical cell structure and no enzyme system to produce energy, and can only grow and reproduce in living cells.
Viruses belong to this type of microorganism. Microorganisms are widely distributed in nature, and there are different kinds of microorganisms in air, soil, rivers, lakes and oceans.
There are also many kinds of microorganisms on the body surfaces of human beings, animals and plants and their cavities communicating with the outside world. Most microorganisms are beneficial and necessary for the survival of human beings, animals and plants.
The circulation of nitrogen, carbon, sulfur and other elements in nature depends on the metabolic activities of microorganisms. For example, a large amount of nitrogen in the air can only be absorbed by plants under the action of microorganisms, while microorganisms in the soil can transform the protein of plants and animals into inorganic nitrogen-containing compounds to meet the needs of plant growth, and plants are used by humans and animals.
Therefore, without microorganisms, plants cannot be metabolized, and humans and animals cannot survive. In agriculture, human beings make extensive use of the characteristics of some microorganisms, and use bacteria to fertilize, promote growth, prevent diseases and treat diseases, thus opening up a new way to increase agricultural production.
In industry, microorganisms are widely used in food, tanning, textile, petroleum, chemical industry and other fields. Especially in the pharmaceutical industry, almost all antibiotics are metabolites of microorganisms, and microorganisms can also be used to make some drugs such as vitamins and coenzymes.
Even many microorganisms parasitic in human and animal body cavities are harmless under normal circumstances, and some of them also have the function of resisting the invasion and settlement of foreign bacteria and providing necessary nutrients (such as vitamins and amino acids) for human beings. A few microorganisms can cause diseases of human beings, animals and plants. These pathogenic microorganisms are called pathogenic microorganisms.
Some microorganisms are not pathogenic under normal circumstances, but can cause diseases under certain conditions, which are called conditionally pathogenic microorganisms. Microbiology is a branch of biology, which studies the evolution and classification of microorganisms, the morphology, structure and life activities of microorganisms under certain conditions, and the relationship between microorganisms and human beings, sports, plants and nature.
With the expansion and deepening of research scope, microbiology has gradually formed many branches, mainly focusing on general microbiology, microbial taxonomy, microbial physiology, microbial ecology, microbial genetics, molecular microbiology and so on. According to the research object, it can be divided into bacteriology, mycology and virology.
According to the research and application fields, it can be divided into agricultural microbiology, industrial microbiology, medical microbiology, veterinary microbiology, food microbiology, marine microbiology, soil microbiology and so on. A brief history of medical microbiology and its development Medical microbiology is a branch of microbiology and a basic subject of medicine.
This paper mainly studies the morphology, structure, metabolic activity, inheritance and variation, pathogenic mechanism, anti-infection immunity, laboratory diagnosis and specific prevention of pathogenic microorganisms related to human diseases. The purpose of studying medical microbiology is to understand the biological characteristics and pathogenicity of pathogenic microorganisms; Understand the immune function of human body to pathogenic microorganisms, the relationship between infection and immunity and its law; Understand the laboratory diagnosis methods and prevention principles of infectious diseases.
Mastering the basic theory, knowledge and skills of medical microbiology can lay a foundation for the study of basic medicine and clinical medicine and help to control and eliminate infectious diseases. Medical microbiology is a science summarized by human beings in the process of long-term understanding of the pathogenic nature of infectious diseases and disease prevention and treatment.
Understanding the past, present and future of medical microbiology is helpful for us to sum up the laws, find the correct research direction and preventive methods, and further develop medical microbiology. 1. Experience in Microbiology Although ancient humans did not observe microorganisms, they had already applied microbiology knowledge in industrial and agricultural production and disease prevention and control. In the Xia and Yu dynasties more than 2000 years BC, there was a record of wine-making in Yidi.
In the Northern Wei Dynasty (AD 386-534), Qi Yaomin recorded the method of making vinegar in detail. For a long time, the common methods of preserving food, such as pickling, adding sugar, smoking and air drying, actually prevent food from rotting and deteriorating by inhibiting the growth of microorganisms.
Regarding the occurrence and prevalence of infectious diseases, 1 1 At the beginning of the century, Liu Zhenren proposed that tuberculosis was caused by insects at the end of the Northern Song Dynasty in China. Italy's fracastoro (1483 ~1553) thinks that infectious diseases can spread directly, indirectly and through the air.
Austria.