Ency123

What is Computer Memory? To process information electronically, data are stored in a computer in the form of binary digits, or bits, each having two possible representations (0 or 1). If a second bit is added to a single bit of information, the number of representations is doubled, resulting in four possible combinations: 00, 01, 10, or 11. A third bit added to this two-bit representation again doubles the number of combinations, resulting in eight possibilities: 000, 001, 010, 011, 100, 101, 110, or 111. Each time a bit is added, the number of possible patterns is doubled. Eight bits is called a byte; a byte has 256 possible combinations of 0s and 1s. A byte is a useful quantity in which to store information because it provides enough possible patterns to represent the entire alphabet, in lower and upper cases, as well as numeric digits, punctuation marks, and several character-sized graphics symbols, including non-English characters. A byte also can be interpreted as a patter...

Structure of an Atom - What is the Structure of an Atom? Atoms are composed of smaller particles called protons, neutrons, and electrons. The Atom consists of a cloud of electrons, surrounding the core - protons, and neutrons.  The electrons and protons have an electric charge, which affects the way they interact with each other and with other electrically charged particles. Electrons have a negative electrical charge, while protons have a positive.  The negative charge is the opposite of the positive charge, and as the opposite poles of a magnet, these opposite electrical charges attract. However, as the charges (negative and negative or positive and positive) repel. The attraction between the electrons of an atom and its protons holds the atom together. Normally, an atom is electrically neutral, meaning that the negative charge of the electrons is exactly equal to the positive charge of the protons. The core contains nearly all of the mass of an atom, but it occupi...

Atom - small basic building block of matter.  All materials on Earth are composed of different combinations of atoms. Atoms are the smallest particles of a chemical element that still have all the unique chemical properties of this element. A row of 100 million atoms would be about a centimeter long. Understanding the atoms is the key to understanding the physical world. More than 100 different elements exist in nature, each with its own unique atomic structure. The atoms of these elements react with each other and make different combinations, forming virtually unlimited number of chemical compounds. When two or more atoms combine, they form a molecule.  For example, the two hydrogen atoms (abbreviated to H) combined with an atom of the element oxygen (O),   form a water molecule (H20). Since all matter, since its creation in the early universe to current biological systems is made up of atoms, understanding their structure and properties play an important r...

White blood cells are almost 900 times less than the red blood cells , there are several types of it, whose primary task is to fight infection. Small red cells are much more numerous in the blood and give it its color. But white blood cells also play an important role. White blood cells are also called leukocytes. The most numerous white blood cells are granulocytes. These cells go in and out in the blood at the point where germs are collected or where is injured tissue. Some of them, which we call Neutrophils, take the bacteria within and destroy them. Leukocytes produce substances that soften and digest dead tissue and produce pus. Other white blood cells are called lymphocytes. Their number is often increased when the body for a longer time is exposed to an infection. They are an integral part of the mechanized body, and as we can see, their role is very important. The third type of white blood cells are Monocytes. These cells, together with other cells in tissues, have the ...

What are red blood cells? Red blood cells (also called erythrocytes) provide a blood red color. There are so many red blood cells in the blood (about 25 billion) which makes them responsible for the red color of the blood. These tiny, round and flattened discs, all at the same time circulate through our bodies and are always found in the blood vessels. It is almost impossible to imagine such a large number, but this may help you to understand it: Each blood cell is so small that it can be seen only under a microscope. If we can connect these microscopic cells into a series, than we could encircle the globe four times! However, during blood tests, only blood cells from one spatial millimeter of blood are counted, not from the whole body. Although these cells are very small, together they cover a huge area. For example, if you have woven them into the carpet, its total area would amount to 4,500 square meters. Given that at any moment one-fourth of blood is in the lungs, an are...

Why am I always tired? Fatigue can be considered a sort of intoxication.  When the muscles of our body work, lactic acid is created. If we remove the acid from the tired muscles, they will be able to work again. During the day, we are, we are “poisoning” ourselves with lactic acid.  Also there are other substances which are produced during muscle work, and these substances are called poisons fatigue. They are carried by the blood throughout the body, so we feel tired not just in the muscles, but also in the entire body, especially the brain. Scientific experiments related to fatigue are showing some interesting results.  If a dog gets tired to exhaustion and sleep, and then its blood is injected into another dog, that dog will also immediately become tired and fall asleep to. If, on the contrary, a tired dog receives a blood transfusion from rested, alert dog, this dog will immediately wake up and will not feel tired. Fatigue is not only a chemical process, but...

In some parts of the body there are cells that can shrivel or relax – these are the muscle cells. There are two types:   smooth and  striated. Smooth muscle s are found in many parts of the body and support the work of almost all organs: they contract and expand the pupil of the eye, regulate breathing and so on. Contraction of smooth muscle is strong, but slow. Where is necessary to move quickly, are located the striated muscle cells . All the muscles that move our limbs are striated. The human body has 639 muscles.  Muscles are actually fleshy parts of the body. Meat purchased from a butcher is striated muscle. Muscles are in different sizes and different shapes. Medium sized muscle is consisted of about ten million of muscle cells, and the whole body from about six billion muscle cells! Each of the six billion of muscle-like cells, is similar to ten-cylinder engine arranged in a single row. Cylinders are tiny boxes containing liquid. Muscle twit...

If the body did not have joints, we would not be able to move.  Than we could only lie completely motionless, unable to move our head, to walk, to raise our hands or move only one finger! All this we can do through the joints. Everywhere where two bones slide over one another, there is a joint. The joint allows the bones to move smoothly with little friction, because the ends of the bones are covered with cartilage, so that the bones do not rub against each other. In addition, the joint is whitish liquid, thick as a living egg, synovial fluid, and it plays the role of lubricating the machine, which reduces friction. When the joint is at rest, it generates very little synovial fluid and joint becomes really creaky. Types of joints In the human body there are four types of joints: angular,  egg-shaped,  in the form of hinge joints and  rotary joints.  Shoulder joint, which is spherical, is the most mobile of all the joints in the body. Therefore,...

The cell is the smallest fraction of every living being. The simplest forms of plants and animals are composed of only one cell. Within the more complex living beings cells work together, organized into groups, each of which has its own task. Tissue is a group of cells of the same type that performs specific task. There is, for example, bone tissue, etc. The tissues are grouped to perform a specific job; such group is called body tissues. For example, the human hand is composed of different tissues: bones, muscles, nerves, etc. In the human body there are five major types of cells.  Epithelial or cover cells build the skin, glands, and line the blood vessels.  Muscle cells built up three types of muscles.  Nerve cells constitute the brain, spinal cord and nerves.  Blood cells are found in lymph.  The binding cells of the human body form the connective tissue, which is the supporting tissue.

What Is Protoplasm? The secret of protoplasm is the secret of life itself. We still do not know what makes the protoplasm a living substance. Protoplasm is the living part of every plant and animal. All organisms, plants and animals, are composed of cells. In one living organism can be millions of cells, as in human body, or just one – like in protozoa (pre-animals). But the walls of the cells of all living beings wrap the same living matter – the protoplasm. In each cell the protoplasm consists mainly of two parts: a stronger central part called the nucleus and the softer, liquid part which is called cytoplasm. Every living specie has its own kind of protoplasm, and the different types of cells in the body have their own forms of protoplasm. Although the protoplasm varies, up to 99 percent of its content consists of carbon, hydrogen, oxygen and nitrogen, with traces of many other elements. When a living beam enters the food it is first digested, ie. converted into ...