Transcript Ch 2

Chemistry
Chapter 2
Atomic Structure
Particles
Proton
Neutron
Electron
Charge
+1
no charge
-1
Mass
1 amu
1 amu
0 amu
Chemical Bonds
Ionic bonds: electrons are transferred
Cation +
Anion –
Covalent bonds: electrons are shared
Polar (slight charge)
Nonpolar (no charge)
Hydrogen bonds: (weak intramolecular bonds)
Chemical Reaction
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Synthesis
Decomposition
Single Displacement
Double Displacement
Hydrolysis
Dehydration
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A+BC
CA+B
AB + C  AC + B
AB + CD  AD + CB
H2O + C A + B
A + B – H2 O  C
Energy Transfer
 Endothermic /
Endergonic –
Absorption of energy
 Exothermic /
Exergonic – Release
of energy
Rate of Reaction
 Temperature – increase in temperature leads
to an increase in kinetic energy (faster moving
particles)
 Particle Size – increased surface area allows
particles to collide more frequently.
 Concentration – the more concentrated a
solution is, the more likely the particles will
collide.
 Catalysts – (enzymes) – help by lowering the
amount of energy needed for a reaction to
proceed. (not used up during the rxn)
Acids and Bases
 pH scale (0 – 14) (measures the hydrogen
ions in a soln)
 Acid (sour taste; corrosive)
 molecule capable of releasing H+
 molecule that absorbs a OH-
 Base (bitter taste; slippery)
 molecule capable of absorbing H+
 molecule that releases a OH-
 Titration – balancing acid and base
Salts
 Formation of a salt
 HCl + NaOH –> H2O
+ NaCl
 Salt is an ionic
compound that
contains cations
other than H+ and
anions other than
OH-
Buffers
 Buffer - a substance
that either releases
or absorbs H+ and
helps to prevent a
drastic change in pH.
 When the buffer runs
out the pH will again
begin to fall with the
addition of more H+.
Carbohydrates
Monosaccharides – simple
sugar (single chain or
ring) ex: glucose,
galactose, fructose
Disaccharides – double
sugar ex: sucrose,
lactose, maltose
Polysaccharides – many
sugars ex: starch,
glycogen, cellulose,
Lipids
 Fats, Oils, Waxes
 Higher number of C – H
bonds than carbohydrates
 Used for Lubrication,
Waterproofing, Insulation,
Energy Storage
 Saturated vs. Unsaturated
 Phospholipids, Steroids,
Triglycerides
Proteins
 Composed of 20 different amino acids. (vary by
the side chain: R-group)
 What makes one protein different from another
is the amino acids making it up and the order
of the amino acids.
Each amino acid has an amine group (-NH2)
and a carboxyl group (-COOH)
Protein Formation
Peptide bond formation: long
chains of amino acids
joined by a dehydration
reaction
Proteins are classified based
on function.
 Folding of proteins creates
different structures:
primary, secondary,
tertiary, quaternary
Proteins can form bonds with
themselves or other
proteins
Protein Classification
2 ways of classifying proteins
Structural Protein – fibrous proteins;
composed of intertwined chains, resembles a
rope, used for support, insoluble (ex: collagen)
Functional Proteins – globular proteins;
compact and spherical, water soluble,
chemically active, mobile (ex: antibodies,
enzymes, and protein-based hormones)
Protein Denaturation
Denaturing – heat or pH effects hydrogen
bonds in a globular protein and can
permanently change it
Denaturation destroys active sites
ex: hemoglobin becomes unable to bind
and transport oxygen when blood pH is
too high
Molecular Chaperones
 Globular proteins that prevent incorrect
folding, help move certain ions across
cell membranes, break down
damaged/denatured proteins, etc.
 Ex: stress proteins- produced in
response to traumatizing stimuli
Enzymes
 Globular proteins that act as catalysts
 They regulate and accelerate
biochemical reactions
 Each enzyme is chemically
specific
Nucleic Acids
 DNA
 Found in the nucleus
 Blueprint of life (CGAT)
 Inheritable
 RNA
 3 types
 mRNA (messenger)
 tRNA (transfer)
 rRNA (ribosomal)
 Single Stranded
 Uracil replaces thymine
 ATP
 Adenosine triphosphate
 energy