Chemistry Pre-Quiz!

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Chemistry Pre-Quiz!
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Question 1

• Biochemistry is the study of ____________.

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Question 2

• An atom consists of protons, neutrons, and
  ____________.

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Question 3

• The molecular formula for water is ____________.

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Question 4

• Which is the smallest?
• Organism
• Cell
• Atom
• Compound

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Question 5

• Glucose is an example of a monosaccharide.
• True or False?

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Chapter 2

• The Chemistry of Life

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Why do biologists need to study chemistry?

• All life forms are MATTER and all matter is made
  up of chemical parts.
• Matter anything that has a MASS and VOLUME that
  can be measured.
• Examples of Matter (living and nonliving)
• All matter has both physical and chemical
  properties.

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Physical Properties

• Can be observed and measured without permanently
  changing the identity of the matter
• Observed by the senses - taste, smell, shape,
  color, texture, melting and boiling points.

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Chemical Properties

• Chemical properties can change a substance into a
  new substance through a chemical reaction.
• New substance is created and permanently altered!
• Rusting (oxidation) and combustion (flammability)
• Examples of chemical reactions

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Levels of Organization(Largest Smallest)

• Organism Organ Systems
• Organs Tissues Cells
• Cell Organelles
• Molecule/Compounds Atoms

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Ch. 2- Section 1
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ATOMS

• Smallest, indivisible unit of matter.
• Extremely small!
• (100 MILLION atoms lined up end to end would
  only equal 1 cm in length!)
• However, an atom is made up of smaller parts
  called SUBATOMIC PARTICLES.

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ATOMS (continued)

• Center of Atom Nucleus
• Subatomic Particles Protons, Neutrons,
  Electrons
• Protons - positively charged particle (1)
• Neutrons- particle with NO CHARGE neutral (0)
• Electrons- Negatively charged particle (-1)

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ATOMS (continued)

• Nucleus contains protons AND neutrons.
• Electrons circle around the nucleus in electron
  clouds or orbitals or valence shells.

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ATOMS (continued)

• Every atom has an ATOMIC NUMBER. The atomic
  number tells you a lot of information.
• This number tells you the type of atom you have.
  (Element name)
• This number ALWAYS tells you the of Protons in
  the atom.
• The atomic is usually the number of neutrons
  and electrons, also. (not always!)
• Example Atomic Number of 6
  6 Protons, 6 Neutrons in the
  nucleus of the atom.
• Use Periodic Table of Elements to look up element
  name for atomic number 6 Carbon

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Elements

• Every element consists of only 1 type of atom.
• Every element has a DIFFERENT atomic number and
  its own symbol on the Periodic Table (PT).
• 109 elements on the PT, 90 are found in nature,
  19 were formed in a laboratory by scientists.

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Using the Periodic Table

• Below the Symbol (C) youll find the elements
  atomic mass.
• Atomic Mass Sum of protons neutrons

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Drawing Atomic Structures

• Look up element on the Periodic Table.
• Write down Atomic Number.
• Draw Nucleus with 3 orbitals surrounding it.
• Inside nucleus, write of protons (p).
• Inside nucleus, write of neutrons (n0).
• Fill in orbitals with correct number of
  electrons.
• First orbital gets only 2 electrons.
• Additional electrons, fill 2nd orbital.
• (up to 8 e-)
• More electrons will go into 3rd orbital.
• (up to 8 e-).

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Drawing Atomic Structures

• Example CARBON

6 p 6 n0
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PRACTICE!Drawing Atomic Structures

• Draw the following elemental atoms.
• Oxygen
• Nitrogen

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Chemical Elements Compounds

• Remember!
• The atomic number of an element NEVER changes! IT
  IS ALWAYS THE OF PROTONS IN THE NUCLEUS!
• However, the number of NEUTRONS can vary from one
  atom of that element to the next.

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Isotopes

• Examples 13C 14C
• All are Carbon atoms, just with different atomic
  MASSES! (same atomic )
• Atoms of the same element, same number of
  protons, but different of neutrons are called
  isotopes.

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Radioactive Isotopes

• The nuclei of some atoms are unstable and will
  from time to time break down, releasing matter
  and energy that we call radiation.
• Atoms that emit (give off) radiation are said to
  be RADIOACTIVE.
• Radioactive Isotopes have many uses for living
  organisms, such as diagnosing and treating
  diseases, sterilize food, and measuring the ages
  of things, like trees or rocks.

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Radioactive Isotopes (continued)

• Examples
• Iodine - 131 (131I) injected into humans to
  study the function of the thyroid gland. Can be
  seen through special equipment that picks up on
  the radiation energy given off by this isotope as
  it travels through the body.
• Carbon-14 (14C) used to treat brain tumors and
  track the ages of trees and fossils.

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Chemical Bonding

• When individual atoms interact, they form
  chemical bonds.
• When chemical bonds form between 2 or more atoms,
  your result is a chemical compound.
• However, atoms combine in a certain way and
  follow a specific set of rules!
• The rules affect the electrons in the outermost
  orbital, or VALENCE ELECTRONS.

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VALENCE ELECTRONS

• When the outermost orbital is full with the
  maximum number of electrons, the atom is very
  stable (happy!). These atoms are unreactive and
  do not combine with other atoms to form
  compounds.
• When the outermost orbital is NOT full, it will
  try and fill its orbital by combining with other
  atoms. To become stable, an atom will either
  GAIN, LOSE, or SHARE electrons. An atom will
  bond with another atom if the bond gives both
  atoms complete valence energy levels.

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Two major types of bonds that can form
compounds

• IONIC BONDS
• COVALENT BONDS

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IONIC BONDS

• DEFINITION A bond that completely transfers
  electrons from one atom to another.
• Electrons are completely given up or taken in
  order for atoms to have a completely full
  outermost orbital. Remember- thats when atoms
  are most happy and stable!

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IONIC BONDS (cont.)
11 p 11 n0
17 p 17 n0
Na
Cl
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IONIC BONDS (cont.)
Happy!
Happy!
NaCl
11 p 11 n0
17 p 17 n0

11 p 10 e- 1
Cl-1
17 p 18 e- 1-
Na1
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Ionic Bonds (cont.)

• When electrons are gained or lost, the elements
  take on a charge. The charge will be either
  positive or negative based on gaining or losing
  electrons. These charged elements are called
  IONS.
• http//www.visionlearning.com/library/flash_viewer
  .php?oid1349mid55
• http//www.youtube.com/watch?vFtw7a5ccubsfeature
  related

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COVALENT BONDS

• DEFINITION A bond that shares electrons from
  one atom to another.
• Electrons are NOT completely given up or taken,
  BUT ARE SHARED. This allows for atoms to have a
  completely full outermost orbital.

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COVALENT BONDS

• Example H2O

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More covalent bonds!
Ionic covalent bonding video
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Chapter 2 Properties of Water
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Properties of Water

• Polar covalent bonds- e- are shared, however,
  electrons are pulled more towards the oxygen, due
  to the more protons ( charges)
  in the nucleus.
• Water is POLAR due to this PULL, or uneven
  distribution of electrons.

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Hydrogen bonds (weak bonds)

• Cohesion- attraction between molecules of the
  SAME substance
• (Ex. Water beads up due to the attraction
  between similar water molecules- Surface
  tension on penny)
• Adhesion- attraction between molecules of the
  DIFFERENT substances
  (Ex. Adhesives like glue, tape, etc.)

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Acids/ Bases/ pH Scale

• Water can break apart into ions
• H2O H OH-
• Water Hydrogen Hydroxide
• Ion Ion
• The pH scale measures the concentration of H
  ions in a solution.

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Acids/Bases

• pH scale ranges from 0-14.
• Any reading BELOW 7 on the pH scale is an ACID.
  (HIGH concentration of H ions)
• Any reading ABOVE 7 on the pH scale is an BASE.
  (LOW concentration of H ions)

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• Acids (Acidic solutions) lower the pH, the
  STRONGER the acid.
• Bases (ALKALINE solutions) higher the pH, the
  STRONGER the base.

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Buffers

• Any pH level near 7, is consider NEUTRAL.
• Buffers can be added to strong acids/bases to
  prevent strong changes in the pH levels.
• Very important for maintaining blood pH in
  humans (HOMEOSTASIS)

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Ch. 3 Organic Macromolecules
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Organic macromolecules

• CARBON ORGANIC
• MACROMOLECULES BIG MOLECULES
• Monomers (one piece) bond together to form
  polymers (many pieces)
• 4 major polymers, or MACROMOLECULES, in living
  things.
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids

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Carbohydrates

• Main source of IMMEDIATE ENERGY in living things.
• MONOMERS (smaller pieces) SUGARS (Saccharides)
• Found in starches such at potatoes, pastas, rice
  etc.

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Proteins

• Control and regulate cell processes, fight
  disease, transport substances for cells.
• MONOMERS (smaller pieces) AMINO ACIDS
• Make up muscles of animals

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Lipids

• Used for ENERGY STORAGE slower release of energy
  than carbs make up cell membranes chemical
  messengers
• MONOMERS (smaller pieces) Glycerol and 3 fatty
  acid chains
• Found in oils, tree nuts, waxes

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Nucleic Acids

• Store and transmit genetic information
• MONOMERS (smaller pieces) NUCLEOTIDES
• Found in DNA and RNA within all cells