Chemistry

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Chemistry

• Microbiologys Building Blocks

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Microbe of the Day

• Lactobacillus acidophilus

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Lactobacillus acidophilus

• Normal flora in GI tact and vagina
• L. gasseri most common of 6 Lactobacilli in human
  GI tract
• Produce acids from lactose
• Relatives ferment yogurt, sourdough bread
• Sold as health supplements (probiotics)

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Lactobacillus acidophilus

• Probiotic (health promoting) activities
• Vitamin K production
• reduction in fecal mutagenic enzymes
• macrophage stimulation
• bacteriocin production
• enhanced barrier functions
• 2006 American Academy of Microbiology, available
  at www.asm.org

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Chemistry

• Microbiologys Building Blocks

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MethaneCovalent Bond

• One C and 4 H atoms share electrons to form the
  molecule CH4

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Hydrogen Bonds

• In H2O, the electrons are closer to the O than to
  the H atoms
• The O is slightly negative and the H atoms are
  slightly positive
• The attraction of a positive H to a negative O of
  another water molecule is hydrogen bonding

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Hydrogen Bond
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Chemical Reactions

• Chemical reactions form or break bonds
• Reactions that require energy are called
  endergonic reactions
• Reactions that release energy are exergonic
  reactions

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Is this an exergonic or endergonic reaction?
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Chemical Reactions

• Synthesis reactions form new bonds (anabolism)
• Decomposition reactions break bonds (catabolism,
  degradation)
• Exchange reactions are part synthesis and part
  decomposition
• Some reactions are reversible

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Important Biological Molecules

• Inorganic molecule
• lacks C
• Ionic bonds
• Organic molecule
• contains C
• covalent bonds

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Water

• Polar molecule unequal distribution of charges
• Hydrogen bonding
• Solvent
• Reactant or product in chemical reactions
• Temperature buffer

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pH
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Functional Groups in Organic Molecules Table 2.3
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Naming Molecules

• Functional groups are used to classify molecules
• EXAMPLE an amino acid would have which
  functional groups?
• A polymer is a large molecule of covalently
  bonded small molecules (monomers)

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Dehydration Synthesis

• Dehydration removes H2O
• Hydrolysis adds water

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Carbohydrate

• (CH2O)n
• Sugars and starches food reserves
• Glycoproteins
• DNA
• Cell walls (peptidoglycan)

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Lipid
Fatty acids are hydrophobic
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Lipids

• Nonpolar molecules of C, H, O
• Triglycerides (fats) glycerol fatty acids.
• Saturated fatty acids (no double bonds between C
  atoms) are more tightly packed than unsaturated
  fatty acids

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Fat (Triglyceride)
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Phospholipids
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Cholesterol A Complex Lipid

• Sterols are found in plasma membranes of one
  group of bacteria

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Amino Acid

• Amino acids have amino and carboxyl groups (Table
  2.4)

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Peptide Bond

• Amino acids form polymers called proteins

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Protein Structure

• Primary linear sequence of aa
• Secondary localized folding
• Tertiary overall 3-D structure
• Quaternary association of 2 or more protein
  subunits into a protein
• Denaturation unfolding

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DNA Structure

• Deoxyribonucleic acid
• A and G are purines C and T are pyrimidines

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DNA and RNA

• DNA contains the genetic blueprint for the cell
• RNA can be messenger, ribosomal, or transfer RNA
  it functions in protein synthesis

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ATP

• ATP has high energy bonds P

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Slime Layer (EPS)

• Slime layer unorganized, loosely attached to
  cell wall

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Biofilms

• Biofilm a microbial community attached to a
  surface
• May be one or several organisms

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http//www.arches.uga.edu/kristenc/cellwall.html
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LPS
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