• All matter is composed of elements, each having one type of atom.
  
  

• Atoms react with one another forming ions, molecules, and compounds.

1. How is an atom organized?
   Answer



2. What are radioactive isotopes and how can they be used for the biological benefit of humans?
   Answer
   
   
3. What are the two basic types of reactions between atoms?
   Answer

• Atoms
• Bonds

• Periodic Table
• Electron Energy Levels

• Chemical Survey

• Atomic Structure (573.0K)
• Covalent Bond (773.0K)
• Ionic Bond (892.0K)

• The existence of living things is dependent on the characteristics of water.
  
  
• The hydrogen ion concentration in water changes when acids or bases are added to water.

1. What characteristics of water help support life?
   Answer
   
   
2. What are the hydrogen ion concentration differences between water, acids, and bases?
   Answer

• Water
• pH

• Molecular Structure of Water
• Water as a Solvent
• pH Scale
• Formation of Acid Precipitation

• Macromolecules are polymers that arise when their specific monomers (unit molecules) join together.
  
  
• The molecules found in cells are carbohydrates, lipids, proteins, and nucleic acids.

1. What is a macromolecule, and what are the four classes of macromolecules in cells?
   Answer
   
   
2. What individual units comprise carbohydrate, protein, and nucleic acid polymers?
   Answer

• Organic Chemistry

• Carbohydrates function as a ready source of energy in most organisms.
  
  
• Glucose is a simple sugar; starch, glycogen, and cellulose are polymers of glucose.
  
  
• Cellulose lends structural support to plant cell walls.

1. What is the usual form of carbohydrates in organisms?
   Answer
   
   
2. What are some examples of different types of carbohydrates?
   Answer

• Carbohydrates

• Lipids are varied molecules.
  
  
• Fats and oils, which function in long-term energy storage, are composed of glycerol and three fatty acids.
  
  
• Sex hormones are derived from cholesterol, a complex ring compound.

1. What is the function of fats and oils, and of what are they composed?
   Answer
   
   
2. What are the uses of steroids in the body?
   Answer

• Lipids

• Unsaturated Fat

• Proteins help form structures (e.g., muscles and membranes) and function as enzymes.
  
  
• Proteins are polymers of amino acids.

1. What are the major functions of proteins in organisms?
   Answer
   
   
2. How do proteins illustrate the principle that the shape of a molecule influences its function?
   Answer

• Proteins

Art Quiz

• Peptide Bonds

• Nucleic acids are polymers of nucleotides.
  
  
• Genes are composed of DNA. RNA serves as an intermediary during protein synthesis.

1. What does it mean to say that DNA is a double helix?
   Answer
   
   
2. What is the function of DNA in cells?
   Answer
   
   
3. What is the function of RNA related to the function of DNA?
   Answer

• Nucleic Acids

Art Quiz

• DNA Base-Pairing and Hydrogen Bonds