Understanding of life

Life is the existing form of protein Group, and the basic factor of this existing form lies in the constant metabolism with the outside world around him. Once this metabolism stops, life will stop, and the result is the decomposition of protein.

Engels' definition of life expresses life as a protein body with metabolism as its basic form of existence, obliterates the difference between life and protein body (organism), confuses the concepts of life and biology, which is not in line with objective reality and violates the logical law of cognition.

The definition of life given by modern biology;

Life is a complex phenomenon of self-reproduction, growth and development, metabolism, genetic variation and response to stimuli.

This definition expresses life as a compound phenomenon of living things. It obliterates the difference between life and biological phenomena and confuses the concepts of life and biology, which does not conform to the objective reality of life and violates the logical law of cognition. ,

Life is a unique phenomenon of organisms, which is composed of polymer nucleic acid protein and other substances. Different from non-living things, living things can form their own bodies and reproduce their offspring by using external substances, grow and develop according to genetic characteristics, and often show the ability to adapt to the environment when the environment changes.

Life is the consciousness of existence expressed by the growth, development, reproduction, metabolism, stress, evolution, movement, behavior, characteristics and structure of organisms.

Life or survival consciousness is the essence, internal regulation and component of living things, and it is the universal law followed by endless changes of living things. Biology is the unity of life, survival consciousness and things.

The growth, development, reproduction, metabolism, stress, movement, behavior, characteristics and structure of organisms are all manifestations of life or survival consciousness. By observing the manifestations of living things, we can judge whether an object has life or survival consciousness, whether it is biological or abiotic.

The definition of life given by molecular biology;

Life is a molecular system composed of nucleic acid and protein, which has the ability to reproduce and react to the outside world.

This definition describes life as a molecular system, that is, life is a biological system, and further describes the molecular system. This definition is not the definition of life at all, but the definition of biology and the definition of molecular system, which completely confuses life and biology.

Let's understand life by enumerating some changes and characteristics of living things.

I. Identification of chemical constituents

In terms of element composition, among the many chemical elements found in 1 10, almost all the elements necessary for biology are specific, among which C, H, O, N, P, S, Ca, Mg and K account for an absolute majority.

In terms of molecular composition, an important feature of an organism is that it basically contains protein, nucleic acids, lipids, sugars, vitamins and other organic substances called biomolecules. These organic molecules have the same structural patterns and functions in various organisms. For example, the genetic materials of all living things are DNA and RNA, the catalytic enzymes in life are all kinds of protein, and all kinds of living things use high-energy compounds (ATP, NADH, ...), which shows that they have a high degree of identity with the biological world in chemical composition.

Second, a neat and orderly structure.

The chemical components of organisms are not randomly stacked together in the body, but orderly. The basic unit of life is the cell (whether it is virus, viroid, prion, etc. It is still controversial that they belong to the category of life, but they all need to complete their life activities normally in the cell structure. Each structural unit in a cell has a specific structure and function. Biological macromolecules, Wu Nu and complexity are not life. Only when macromolecules form a certain structure or form an orderly system like cells can life be expressed. Without order, if cells are homogenized, life will be over.

The biological world is a multi-level and orderly structure. There are also levels of organization, organ, system, individual, population, community and ecosystem above the cell. Every structural unit at every level, such as organs in the nine systems of human body, has its specific structure and function, and the coordinated activities of experts constitute a complex life system.

Third, metabolism.

The organism is an open system, and the material exchange and energy flow between the organism and the surrounding environment are continuous. After some substances are absorbed by organisms, a series of changes occur in the body, which become the final products and are excreted. This is called metabolism. Metabolism is a neat and orderly process and a reaction network composed of a series of enzymatic chemical reactions. If the order of metabolic process is disrupted, for example, some links are blocked, the whole metabolic process may be disrupted, life will be threatened, and even life will end.

Fourth, pressure.

Living things can accept external stimuli and respond to their purposes. Includes two processes: feeling stimulation and reaction. The result of the reaction is that organisms "seek advantages and avoid disadvantages." Drop a drop of acetic acid in a drop of paramecium suspension, and paramecium will swim one by one; A piece of carrion can attract flies; Plant shoot tips grow towards light, which is pressure.

Stress is a universal feature of living things. The stress performance of animals is more obvious and diverse. Sensory organs and motor organs of animals are the products of highly developed stress.

Verb (abbreviation of verb) steady state

100 years ago, C. Bernard discovered that although the external environment fluctuates greatly, mammals always have some mechanism to keep their internal environment unchanged. Later, W.B. Cannon developed this concept into a steady state. Later, it was found that not only mammals, but all organisms, cells, communities and even ecosystems are stable without strong external factors, and each of them has its own specific mechanism to ensure its own dynamic stability.

VI. Growth and Development

All living things can grow and develop through metabolism. A seed can become a tree, so that everyone can become a frog. Although environmental conditions will affect the growth and development of organisms, the growth and development of each organism is carried out according to a certain pool area, a certain model and a stable procedure.

Seven. Genetic variation and evolution

No individual organism can exist for a long time. They can continue their life by reproducing and producing offspring. The similarity between offspring and parents in morphological structure and physiological function is the result of heredity. The difference between parents and children is caused by variation. From about 3.8 billion years ago to the present, the evolution process of organisms from simple to complex and from low to high is the result of evolution.

Eight. adapt to

Every creature has its own unique living environment, and its unique structure and function are always suitable for survival and continuation in this environmental condition. For example, the structure of fish gills is suitable for fish to breathe in water, while the lung structure of terrestrial vertebrates is suitable for land breathing. Adaptation is a unique phenomenon in life.

The adaptation of any living thing to the environment is always relative. Due to genetic and phenotypic differences, individuals of the same species always have different degrees of adaptation to the environment. As long as there are such differences, even slight differences, natural selection will play a role in promoting the evolution of the population in a more adaptive direction.

Two articles about life:

First, "life and its meaning"

(Author: Haron Lee)

Your life does not belong to you.

It belongs to everyone who cares about you.

Therefore, cherishing life is an obligation, not a right.

The meaning of your life belongs only to yourself.

It doesn't belong to anyone

So you have the right to choose waste or abundance. ...

Second, life, life

(Author: Xing Linzi)

Small moths are struggling in danger, fragrant melon seeds are growing seedlings in the cracks in the corner bricks, and "I" listen to my heartbeat and feel my life. These are ordinary things, but the author has learned a profound truth from them. Try to contact the author's life experience and understand why she shouted "life, life" strongly.

I often think, what is life?

At night, I was writing under the lamp, and a moth kept flying over my head and harassing me. When it stopped, I reached out and grabbed it. As long as I push my finger a little harder, it won't move. But it struggled and tried to encourage its wings. I felt a force of life in my hands, so powerful! So vivid! The moth's desire to survive shocked me, and I couldn't help letting go!

A sweet melon seed fell into a brick crack in the corner. A few days later, a small melon seedling appeared. What a powerful vitality that little seed contains! Unexpectedly, it can break through the hard shell and grow indomitable in the cracks of bricks without sunlight and soil, even if it only lives for a few days.

Once, I listened to my heartbeat with a doctor's stethoscope, and the steady and regular beating gave me a great shock. This is my life, only mine. I can make good use of it or spoil it for nothing. It's up to me. I must be responsible for myself.

Although life is short, we can make limited life show infinite value. So, I made up my mind to cherish my life, never let it pass in vain, and let myself live more wonderfully.

3. Cherish life.

Shuttle through the white ward every day, thinking about those patients, when sound waves penetrate the eardrum, my heart is also sad. Looking at those eyes full of longing for life and trust in medical care, I was deeply shocked. Use my blood, my hands and my wisdom to soothe those sad hearts. Then laughter will continue to appear in the ward. But sometimes, despite this, the cancer demon will mercilessly take innocent lives. To this end, I ask heaven: why does our modern medicine sometimes seem so pale and powerless? ! I mused. ......

Death is the end of life. Life is short, you should know how to cherish it when you are healthy. Don't cherish when your life comes to an end. Don't miss it for a moment of beauty and wine. And greed; And forget the potential of the disease, the bane of the disease deterioration.

To enjoy life, you must treat life well. Compared with the vast history, life is a short moment. Power is a thing of the past, and money is a thing outside. Cherish life and take care of your health. I would rather be poor all my life than be rich for a while. This is an understanding of being a man.

Being alive is also a kind of luck. Cherish life and enjoy life, which is the greatest happiness. There is no need to regret yesterday's disappointment, nor to worry about today's loss, let alone the gains and losses of the Ming Dynasty. Look at the mountains, be calm, be broad-minded, have a psychological balance, be content with contentment, and reach the highest level of kindness to life in order to truly enjoy every day. Friend, life is colorful, cherish life.