The 6 Essential Elements

Inorganic Compounds Living things are composed of two main types of chemical compounds: Inorganic: compounds that do not contain carbon C

Example #1 Water – (hydrogen and oxygen) the most important inorganic compound to living organisms Water makes up most of a cell. Water also helps to transport molecules in a cell Water is like the roads on our street; it makes it much easier for atoms and molecules to move around in your body.

Example #2 Salts –give elements to parts of the cell Ex. NaCl dissolves in solution to form Na+ and Cl- The Sodium is used by our brains! The Chlorine helps absorb water and digest food.

I. Why do living things need the six essential elements (CHNOPS)? Organic: compounds that DO contain carbon, oxygen, and hydrogen Carbohydrates (carbon, hydrogen, oxygen) Ex. Provide energy source for respiration (glucose) Lipids (carbon, hydrogen, oxygen) Ex. Insulate and protect organs in the body (fats) Nucleic Acids (carbon, hydrogen, oxygen, nitrogen and phosphorus) Ex. Allow traits to be passed from parent to child (DNA) Proteins (carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus) Ex. Provide specifically shaped molecules that can carry other molecules (hemoglobin carries oxygen)

Functions of carbohydrates Energy is released when carbohydrates are digested. This is because glucose (sugar) is used for cellular respiration (breathing). Simple sugars provide short term energy. Complex sugars, such as starch and glycogen, are considered long-term energy sources because they take much longer to breakdown.

Functions of lipids Because of the numerous bonds and the way the body stores lipids, they can be used as very long-term (weeks, months) energy sources. Ex. Bears accumulate a layer of fat before winter (when food will be less available) Fats stored in the body act as insulation and protection for internal organs. Some hormones are composed of lipids (steroids).

DNA and RNA help create proteins in the body. Functions of nucleic acids DNA makes up the genes. Genes are used to pass traits from parent to offspring. Genes determine traits. DNA and RNA help create proteins in the body.

Functions of proteins Some proteins absorb light. These are called pigments and they create color by reflecting certain wavelengths of light. Ex. Chlorophyll absorbs light to gather energy for photosynthesis. Some proteins form antibodies, which attack foreign pathogens (molecules that make us sick). Proteins help form keratin, which is found in hair and nails.

Some proteins are used for transport (ex. Hemoglobin transports Oxygen) Some proteins are used for communication between cells (ex. Hormones). Enzymes (a protein) speed up chemical reactions.