AP BIO Unit 1

• What are all substances made up of?

  Atoms
• Why are atom molecules necessary?

  They are necessary to build new molecules
• What is the composition of a hydrogen atom?

  1 proton and 1 electron
• What is the composition of an oxygen atom?

  8 protons, 8 neutrons, and 8 electrons
• What determines the kind of bond formed between atoms?

  Electron number and arrangements
• What are the types of chemical bonds?


  • Hydrogen bond: Between partially charged atoms
  • Ionic bond: Metal donates an atom to a nonmetal
  • Covalent bond: Nonmetals share electrons
  • Metallic bond: Holds atoms in metallic substances
• What is a hydrogen bond?

  It forms when two partially negative charged hydrogens and one partially positive oxygen bond covalently
• How does an ionic bond form?

  A metal atom donates an atom to a nonmetal atom
• What characterizes a covalent bond?

  Two nonmetals share electrons
• What is a metallic bond?

  It is the force that holds atoms together in a metallic substance
• Why is water considered polar?

  Because it has hydrogen bonds
• What are the properties of water?

  • Cohesion: Water molecules stick to each other
  • Adhesion: Water sticks to other molecules
  • Surface tension: Resistance to being stretched
  • Unusual phase change: Density decreases when frozen
• What is cohesion in water?

  It is the tendency of hydrogen molecules to stick to each other through hydrogen bonding
• What is adhesion in water?

  It is the tendency of hydrogen to stick to other molecules via hydrogen bonding
• What causes surface tension in water?

  Hydrogen bonds resisting being stretched due to water's polarity
• What is unusual about water's phase change when it freezes?

  Its density lessens, unlike other solids
• What is ionization?

  It is the process in which an atom or molecule acquires a charge by losing or gaining electrons
• What is high heat of vaporization?

  It is the amount of energy needed to change one gram of a liquid to gas at constant temperature
• What does high specific heat mean for water?

  It takes more energy to increase the temperature of water compared to other substances
• Why is water considered a versatile solvent?

  It is excellent at dissolving polar molecules
• What happens when water ionizes?

  It produces hydroxyl ions
• How many hydrogen bonds can one water molecule form?

  Up to 4 hydrogen bonds
• How do organisms interact with their environment?

  • Exchange matter to grow
  • Reproduce
  • Maintain organization
• What are the main elements of life represented by CHONPS?

  Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur
• What is the role of carbon in biological molecules?

  It is used to build biological molecules like carbohydrates, proteins, and lipids
• In what forms is carbon used in organisms?

  In macromolecules, storage molecules, and cell formation
• What is phosphorus used for in biological systems?

  To build nucleic acids
• What is nitrogen's role in biological molecules?

  It is used to build proteins and nucleic acids
• What are lipids and their characteristics?

  • Nonpolar molecules
  • Include fats, oils, waxes
  • Composed of fatty acids and glycerol
• What are saturated fats?

  Fats with no double bonds, solid at room temperature
• What are unsaturated fats?

  Fats with one or more double bonds, liquid at room temperature
• What is the structure of triglycerides?

  Three fatty acids bonded with glycerol
• What are proteins made of?

  Amino acids
• How many essential amino acids are there?

  9 essential amino acids
• What are the four levels of protein structure?

  Primary, Secondary, Tertiary, Quaternary
• What happens to denatured proteins?

  They do not work
• What determines the properties of biological molecules?

  • Subcomponents of molecules
  • Sequence of subcomponents
• What is a monomer?

  A subunit that serves as a building block for polymers
• What is a polymer?

  A large molecule made up of many similar/identical monomers linked together
• What is the monomer of proteins?

  Amino acids