8/18/2016 Important Biological Molecules Inorganic Compounds Inorganic Compounds Small and structurally simple Learning Objectives Typically lack carbon Examples:water,oxygen,carbon dioxide,salts, List several properties of water that are acids,and bases important to living systems Define acid,base,salt,and pH Organic Compounds Always contain carbon and hydroger Examples:structurally complex polysaccharides, proteins,and nucleic acids(macromolecules) Water Water is a Good Medium for Living Cells All living organisms require a variety of Exists mostly as liguid on Earth inorganic compounds for growth,repair, -strong attraction for other water molecules maintenance,and reproduction requires heat to form vapor == Water is vital and makes up on average 65%- Good solvent(dissolving medium)due to 75%of every cell polarity For microorganisms,outside the cell nutrients polar substances dissociate forming solutes are dissolved in water,which aids their passage into the cell Key reactant in the digestive process and in the synthesis of organic compounds in cells Water is a polar molecule since it -H'and O participate in chemical reactions has a slight negative and a Maintains a constant temperatur slight positive charge H a good temperature buffer for living cells Polar molecule Due to the H-bond of water molecules 8/18/2016 3 Inorganic Compounds Small and structurally simple Typically lack carbon Examples: water, oxygen, carbon dioxide, salts, acids, and bases Organic Compounds Always contain carbon and hydrogen Examples: structurally complex polysaccharides, proteins, and nucleic acids (macromolecules) Important Biological Molecules Learning Objectives List several properties of water that are important to living systems Define acid, base, salt, and pH Inorganic Compounds All living organisms require a variety of inorganic compounds for growth, repair, maintenance, and reproduction Water is vital and makes up on average 65%- 75% of every cell For microorganisms, outside the cell nutrients are dissolved in water, which aids their passage into the cell Water is a polar molecule since it has a slight negative and a slight positive charge Water Polar molecule Water is a Good Medium for Living Cells Exists mostly as liquid on Earth - strong attraction for other water molecules - requires heat to form vapor Good solvent (dissolving medium) due to polarity - polar substances dissociate forming solutes Key reactant in the digestive process and in the synthesis of organic compounds in cells - H+ and O- participate in chemical reactions Maintains a constant temperature providing a good temperature buffer for living cells - Due to the H-bond of water molecules Water acts as a solvent for sodium chloride