Transcript Chapter 2: Chemistry

Chapter 2: Chemistry
What is matter made up of and how does
it react?
What is Matter?
• Anything that occupies space and has mass.
Elements
• Pure substance made up of only one kind of
atom
• 90 occur naturally
• 25 essential to life: C,H,O,N
– 0= 65%, C=18.5%, H=9.5%, N=3.2%
• Atom: smallest unit of matter that cannot
be broken down by chemical means.
Periodic Table
• Atomic Symbol: C = carbon, or Au = gold
• Atomic Number: Number of Protons in an
Atom. Carbon has ? Gold has ?
• Atomic Mass: Number of Protons and
Neutrons.
• Isotope: Different numbers of Neutrons
than Protons
Periodic
Table
Atoms
• Three major parts.
– Protons: Positive Charge. Inside Nucleus
– Neutrons: Neutral Charge. Inside Nucleus:
– Electrons: Negative Charge. Outside Nucleus
• 2 electrons in first shell
• 8 electrons in the second shell
• Eight is Great! Will not React with other
atoms.
• If the outer shell is not full it will react.
Combining Chemicals
Periodic
Table
Bonding
• Compound: When two or more different elements
combine.
• Hydrogen Bond: H2O
– When hydrogen bonds with another atom. Creates a
polar molecule.
• Covalent bond: CO2
– When atoms on the same side of the chart (same size)
bond. Share electrons.
Ionic/
• Both Hydrogen and Covalent bonds form
Covalent
molecules, ionic bonds do not.
Bonds
Review of Chem
Review
of Chem
Combining Chemicals continued
• Ionic Bonds: When atoms on different
sides of the chart (different size) bond.
Steal electrons. Create Ions. Make teeth and
bones.
• Ion: Charged particle either negative or
positive. NaCl = table salt
• Free Radical: Electrically charged ion
with an unpaired electron in its outer
shell.
Antioxidants, What are they?
• Substances that inactivate oxygen derived
free-radicals
• Slows damage from free-radicals
• Examples: Selenium, Zinc, Betacarotene, Vitamins C & E
Free Radicals
Acai Berry
Energy and Chemical Reactions
• Reactants and Products
– Co2 + H20 = H2C03
• Energy Transfer
– Exergonic Rxns- Energy exits or released
– Endergonic Rxns- Net absorption of energy
• Activation energy
Enzyme song
– Energy needed to start the reaction. Catalysts
reduce the energy needed. Often enzymes.
Endothermic Rxn
Exothermic Gummi
Reduction-Oxidation Rxns.
• Redox Reaction: Reactions in which
electrons are transferred between atoms.
• Oxidation Reaction: a reactant looses one
or more electrons. The reactant is now
positively charged.
• Reduction Reaction: a reaction gains one
or more electrons. The reactant is now
Flamming
negatively charged.
Gummi
bear
Solution
• A mixture in which one or more substances
are evenly distributed in another substance.
• Solute: smaller word, smaller thing
• Solvent: bigger word, bigger thing
Types of solutions:
• Aqueous Solutions: water is the
solvent.
• Saturated solutions: no more solute
can dissolve in the solvent.
• Concentration: the amount of solute
dissolved in a fixed amount of a
solution.
The Importance of Water
• Polar molecule (it has a negative and positive
charge.)
– Can dissolve both Ionic and Polar-Covalent
molecules
• Surface Tension
– Cohesion: Sticks to itself.
– Adhesion: Like a band-aid. Sticks to stuff
• Capillary Action: Climbs up thin tubes
Importance of Water
• Evaporates: Cooling, Water cycle, etc
• Resists Temperature Change: Takes
a lot of energy to heat or cool water
• Expands as it Freezes.
Ph Scale
• Measured on grams of Hydrogen (H+)
– pH of 1= 1g of H+, pH of 2= .01g of H+
• Acid: form hydronium ions (H+)
– pH of less than 7 ( 1 to 6.9)
• Base: form hydroxide ions (OH-)
– pH of more than 7 (7.1 to 14)
• Acid + Base: salt & water, the solution is
neutral with a pH of 7.
– NaOH + HCL = H2O + NaCl with a pH of 7
What is a Buffer?
• Chemical substances that neutralizes small
amounts of an acid or base added to a
solution.
• Why are these important to your body?
Organic Compounds: C-H
Carbohydrates
• Carbohydrate: fast energy
– made of Carbon, Hydrogen, and
Oxygen. 1:2:1 proportion. Sacchar
= sugar
• Monosaccharides:C6H12O6,
glucose, fructose, & glactose
• Disaccharides: 2 sacchar’s:
Sucrose, table sugar
• Polysaccharides: Many sacchar’s:
Cellulose (wood) and starch.
Organic Compounds: C-H
• Lipids: Fats long term energy storage
–Have very few oxygen atoms
–Saturated fats: All C bonded to
H. Lard, and butter.
–Unsaturated fats: C is double
bonded to itself. Oil.
Lipids
Organic Compounds:
All organic compounds contain Carbon.
• Protein: the working molecule
– 50 or more Amino Acids make a
protein
– Types of Proteins
Protein
• Muscle
• Enzymes: Control chemical reactions
and can be re-used like a key in a lock
• Hair
Organic Compounds:
All organic compounds contain Carbon.
• Nucleic Acids: pg. 37 DNA and
RNA
–Made of nucleotides: Sugar,
Phosphate, and X
• ATP: energy cells run on.
DNA