CHEMISTRY OF LIVING THINGS - PowerPoint PPT Presentation

CHEMISTRY OF LIVING THINGS

• Defined as the study of the structure of matter and the composition of substances, their properties, and their chemical reactions
• Biochemistry is the study of chemical reactions of living things

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• Matter is anything that has weight and occupies space; it is neither created nor destroyed
• Energy is the ability to do work or to put material into motion and exists in the body as:
• Potential energy
• Kinetic energy

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• An atom is the smallest piece of an element
• Atoms are made of subatomic particles
• Protons have a positive charge
• Neutrons have no charge
• Electrons have a negative charge

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• Isotopes are atoms of a specific element with the same number of protons but a different amount of neutrons
• Radioactive Isotopes are unstable and may decay

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• Atoms that are alike combine to form elements
• There are 92 elements found naturally and each is represented by a chemical symbol or abbreviation

© 2004 Delmar Learning, a Division of Thomson Learning, Inc.

• Organic compounds are compounds found in living things containing the element carbon
• Molecules are the smallest units of compounds that retain its properties and remain stable

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• Ions are atoms that have more protons than electrons; creating a positive charge
• Electrolytes are atoms that have more electrons than protons; creating a negative charge

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• Inorganic Compounds
• Made of molecules that do not contain carbon (C)
• Organic Compounds
• Always contain the element carbon (C)
• 4 Groups of organic compounds are:
• Carbohydrates • Proteins
• Lipids • Nucleic acids

© 2004 Delmar Learning, a Division of Thomson Learning, Inc.

• All carbohydrates are compounds of carbon, hydrogen, and oxygen
• 3 Groups of carbohydrates:
• Monosaccharides
• Disaccharides
• Polysaccharides

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• Lipids contain less oxygen than hydrogen
• Examples of lipids:
• Fats
• Phospholipids
• Steroids

© 2004 Delmar Learning, a Division of Thomson Learning, Inc.

• Proteins are among the most diverse and essential organic compounds found in all living things
• Amino acids are the small units that make up protein molecules
• Enzymes are specialized protein molecules that help control chemical reactions in a cell

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• Nucleic acids are the largest known organic molecules; made from thousands of repeating subunits called nucleotides
• There are two major types of nucleic acids:
• DNA
• RNA

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• Acids are substances that yield hydrogen ions in solution
• Bases are substances that ionize into negatively charged hydroxide ions and positively charged ions of metal when dissolved in water
• Salts are formed when acids and bases are combined

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• pH measures acidity or alkalinity of a solution
• The pH scale ranges from 0 to 14
• A pH between 0 and 6.9 is acidic
• A pH between 7.1 and 14 is alkaline
• A pH of 7.0 is neutral as it contains the same number of hydrogen and hydroxide ions

© 2004 Delmar Learning, a Division of Thomson Learning, Inc.