Calcium
From the Simple English Wikipedia, the free encyclopedia that anyone can change
Calcium is a chemical element. Its symbol on the periodic table (a list of all the elements) is Ca. Its atomic number is 20. (The atomic number says where Calcium sits in the periodic table.)
Calcium is a soft white-gray substance. It is the 5th most common element on the earth.
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[change] Calcium in living things
Calcium is very important for all organisms. To stay healthy it is important to eat calcium every day. Without enough calcium bones can become weak. This is called osteoporosis.
[change] Calcium in cells
It is important to know how cells work. Many cells have calcium channels on their surface. These are openings where calcium can enter the cell. The cell is told to act and it opens the channels. Once in the cell calcium activates many proteins to do specific things. For example, when it goes into muscle cells, it makes them contract (shorten so the muscle pulls.) When it goes into nerve cells, it triggers electrical impulses that send a messages. When it goes into white blood cells it makes them fight germs.
Calcium is important to cells and too much calcium can be bad. If a cell gets more calcium than it needs it can die. This is why the amount of calcium in cells is highly regulated. Conversely, not enough calcium is bad. Cells must have the right amount to function properly.
Sometimes cells are unhealthy and need to die in for the body to replace them with new, healthy cells. This keeps the whole organism healthy. Cells know when they should die and can trigger reactions to end their life cycles in many ways. When this happens it is called apoptosis, also known as a 'programmed cell death' (planned cell death.) One way cells accomplish apoptosis by taking in toxic levels of calcium.
[change] Calcium storage
Bones contain most of the calcium in the human body. If we need more calcium for our blood, muscles, or other tissue, it comes from the bones. If we have extra calcium it goes into bones.
[change] Calcium regulation
Organisms need to keep calcium levels very well controlled. High calcium levels are bad. Low calcium levels are bad.
The body controls this by changing
- how much calcium we get from the food we eat
- how much calcium we lose in urine
- how much calcium is put in bones
The control of calcium in the body is called calcium metabolism.And is really important, so start eating calcium!!
The body controls calcium levels with many hormones. Calcitonin, Parathyroid hormone (acronym PTH), and Vitamin D are the most important hormones in calcium metabolism. (Vitamin D is a hormone but it is called a vitamin.)
[change] Calcium in Industry
Calcium is also important in chemistry. It is important for making things. It is a part of cement which is needed to make concrete (a hard substance that many buildings are made from.)
Calcium is part of quicklime (calcium oxide – CaO). Quicklime is used to make paper, pottery, food, and to purify water (make it good to drink.)
