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Basic Chemistry Concepts. Structure and function of all living things are governed by the laws of Chemistry Understanding of Chemistry’s fundamental principles provides a better understanding of living things and how they function. Composition of Matter.

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basic chemistry concepts

Basic ChemistryConcepts

Structure and function of all living things are governed by the laws of Chemistry

Understanding of Chemistry’s fundamental principles provides a better understanding of living things and how they function

composition of matter
Composition of Matter
  • Everything in the universe is made of matter
  • Matter is anything that has mass and takes up space
elements
Elements
  • Pure substances that cannot be broken down chemically into simpler kinds of matter
  • Periodic Table gives:
  • Atomic Number
  • Chemical Symbol
  • Atomic Mass
slide4
Of more than 100 elements, fewer than 30 are important in living things
  • More than 90% of the mass of living things is composed of:
    • Oxygen (O)
    • Carbon (C)
    • Hydrogen (H)
    • Nitrogen (N)
atoms
Atoms
  • Simplest particle of an element that retains all of the properties of that element
    • Basic building blocks of all matter
  • Contain 3 types of particles:
    • Protons
    • Neutrons
    • Electrons
the nucleus of an atom
The Nucleus of an Atom
  • The central core of an atom
  • Most of the mass is here
  • Contains two kinds of particles
    • Protons: POSITIVE CHARGED PARTICLE
      • All atoms of an element have the same number of protons
      • Number of protons = atomic number
    • Neutrons: NO ELECTRICAL CHARGE
      • Number of protons + neutrons = atomic mass
      • Same element with different neutrons: isotopes
electrons
Electrons
  • Third type of atomic particle
    • NEGATIVELY CHARGED PARTICLES
  • Very small and move around the nucleus at very high speeds
  • Number electrons = number protons
slide8
Electrons move in different energy levels
  • Each energy level can hold only certain # of electrons
    • 1st level: 2
    • 2nd and other outer levels: 8
  • A stable atom is one that has a full outer level
compounds
Compounds
  • Pure substances that are made up of atoms of two or more elements that are chemically combined
    • Proportion of each kind of atom is fixed (for example, H2O: chemical formula)
slide10
Compound properties (physical and chemical) are different from individual element properties
  • Elements tend to combine depending on number and arrangements of electrons
    • Working toward more stable state

NaCl

chemical reactions and bonds
Chemical Reactions and Bonds
  • Atoms undergo chemical reactions to become more stable
  • In reactions, chemical bonds are broken, atoms rearranged, and new bonds (or attachments) are formed
  • Metabolism: all of the chemical reactions that occur in an organism
  • Two types of chemical bonds:
    • Covalent Bonds
    • Ionic Bonds
covalent bonds
Covalent Bonds
  • Two atoms SHARE one or more pairs of electrons
    • Most compounds in organisms have covalent bonds
    • A group of atoms held together by covalent bonds is called a molecule
ionic bonds
Ionic Bonds
  • Formed by electrical attraction between two oppositely charged ions
    • Ion: atom or molecule with an electrical charge
energy and chemical reactions
Energy and Chemical Reactions
  • Energy is required to make or break chemical bonds, at least for the reaction to begin
  • Chemical reactions that involve a net release of energy: exergonic reactions
    • May be used to do other work
  • Chemical reactions that involve a net absorption of energy: endergonic reactions
catalysts in chemical reactions
Catalysts in Chemical Reactions
  • For many compounds, the amount of energy needed to start the reaction (called activation energy) is HIGH
  • Catalysts are chemical substances that reduce the amount of activation energy needed
    • With a catalyst, the reaction may proceed spontaneously or with only small amount of energy
  • Enzymes are important catalysts in living things
chemical equations
Chemical Equations
  • Shows the changes occurring in a chemical reaction
    • Reactants are on the LEFT side
    • Products are on the RIGHT side
solutions
Solutions
  • Mixtures in which one or more substances are UNIFORMLY distributed in another substance (example: sugar water)
    • Sugar is the solute (substance dissolved)
    • Water is the solvent (substance in which the solute is dissolved)
  • Aqueous solution: water is the solvent
    • Universally important in living things
acids and bases
Acids and Bases
  • On ph Scale from 0-14
    • 0 = very acidic (more H+ ions)
    • 7 = neutral
    • 14 = very basic or alkaline (more OH- ions)
  • Buffers neutralize solutions (example of homeostasis in living things)
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