Elements+Required+By+Living+Things+Life

CHNOPS https://www.youtube.com/watch?v=DeIQvs5LsOs 7min Recipe of Living Things https://www.youtube.com/watch?v=CPmM-yeQQyI SciShow https://www.youtube.com/watch?v=H8WJ2KENlK0

https://sciencing.com/six-elements-occur-living-organisms-8224328.html https://sciencing.com/major-chemical-elements-found-cells-biology-21339.html https://sciencing.com/elements-found-living-organisms-8335998.html https://sciencing.com/elements-found-living-organisms-8335998.html

About 25 common elements make up living things. Close to 100 elements occur naturally. Of these, 25 are found in living things. As you can see in the pie graph at the left, about 97 percent of your body’s mass consists of just four major elements— oxygen, carbon, hydrogen, and nitrogen.

Major Elements The six most common elements in living things are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur. Atoms of these elements combine and form thousands of large molecules. These large molecules make up the structures of cells and carry out many processes essential to life. Later in this chapter you will learn about the properties of carbon atoms that allow them to form a huge number of different large molecules. Carbon molecules can be long chains or rings of atoms. Some are even a combination of chains and rings. We call life on Earth carbon-based because of carbon’s essential role.

Other Elements Other elements are also important to the proper functioning of organisms. These elements include sodium, chlorine, fluorine, potassium, calcium, iron, and magnesium. The illustration on page 341 presents an overview of some important functions of these elements. The following are only three examples. • Sodium (Na+) and potassium (K+) ions play a key role in the transmission of nerve impulses between your brain and all parts of the body. • Calcium (Ca2+) ions are essential for muscle contractions and the clotting of blood. • Fluorine forms a salt with calcium. This salt makes the teeth stronger.

There are even some very important elements that are present in only small amounts. They may seem insignificant. They are not. For example, iron makes up only about 0.004 percent of your body mass, but you couldn’t live without it. Oxygen from the air you breathe binds to the iron in the hemoglobin molecules in your blood. The blood carries this oxygen to body cells, where it is used in cellular respiration.