Micro ch.7

Organic Molecules

•Biochemistry – study of life chemistry

Major cellular elements (macronutrients):

1.Hydrogen

2.Carbon

3.Oxygen

4.Nitrogen

5.Phosphorus

6.Sulfur

•99% of cell dry weight

•4 most common: H, C, O, N

Organic Molecules

Micronutrients:

1.Sodium

2.Potassium

3.Magnesium

4.Zinc

5.Iron

6.Calcium

7.Molybdenum

8.Copper

9.Cobalt

10.Manganese

11.Vanadium

Less abundant, but equally important

Organic Molecules

•Organic molecules = carbon & combo of macronutrients

•Mostly larger and more complex

•Form cell structures

•Held together by covalent bonds

•Inorganic = no carbon

•Simpler and smaller

•Do not form cell structure

Organic Molecules:

Carbon Skeletons:

•Carbon molecules have varying sizes and arrangements

•Arrangements can be chain, branched, or cyclic

Organic Molecules

•Structural isomers – carbon molecules with same formula but different arrangement

•Example: sugars = C6H1206

Organic Molecules

•Stereoisomers – same sequence, same structure, but different 3D shape

•Enantiomers – related by reflection to ea. other

•Organisms may only want one type of enantiomer

•Can give drugs different therapeutic effect

Biological Functional Groups-

Groups of atoms with a specific chemical composition attached

to carbon chain, branching, or cyclic formation

Macromolecules

Chains of carbons with various functional groups

•Monomers – building block of (most) macromolecules

•Polymers – repeating monomers

Macromolecules

Some polymers are formed through dehydration synthesis (water formed as byproduct)

•7.2 Carbohydrates

Carbohydrates

•Most abundant macromolecule

•Serve as food source, structure, and transmitting genetic info

•Provide energy in form of starch & glycogen

Types:

•Monosaccharides – simplest building block of carbohydrates (monomer)

•Polysaccharides – polymers of monosaccharides

Carbohydrates

•Monosaccharides – simplest building block of carbohydrates

•Classified on carbonyl group placement (C=O) and number of carbons

Carbohydrates

•Disaccharides – chain of two monosaccharides

•Bonded with a glycosidic bond

Carbohydrates

•Polysaccharides – polymer chain of monosaccharides

•Bonded with a glycosidic bond

•Examples: agar, cellulose, starch, chitin, peptidoglycan

wheat starch

glycogen granules

bacterial cellulose

•7.3 Lipids

Lipids

Function: nutrients, carbon & energy storage, structure for membranes & hormones

Types:

1.Fatty Acids

2.Phospholipids

3.Isoprenoids/Sterols

Fatty Acids

•Long chained hydrocarbons with terminal carboxylic acid

•Hydrophobic/non-polar

•Saturated or unsaturated groups

Fatty Acids

•Triglycerides – 3 fatty acids + glycerol molecule

•Common to adipose tissue & sebum oil

•Phospholipids – lipids with phosphate group

•Chains may be

saturated or not

•Amphipathic

allows for various

formations

Phospholipids and Membranes

•Micelles – spherical assembly of phospholipids

•Membranes – bilayers of phospholipids

Liposomes

Micelles

Bilayers

Phospholipids and Membranes

Isoprenoids

•Isoprenoids – branched lipids (aka terpenoids)

•Uses: pharmaceuticals, pigments, fragrances

•Found in many hydrophobic oils & waxes

•Many bacteria rely on isoprenoids

Ex. Propionibacterium acnes

Steroids

•Rigid structure in membranes

(especially when no wall present)

•Fungi & protozoa - ergosterol

•Bacteria - hopene

•7.4 Proteins

Proteins

•Polymers of amino acids

•Amino acids =

H atom + carboxyl + amino + side chain

Proteins

•Polymerization occurs via peptide bond & dehydration synthesis

•Polypeptides = <50 amino acids

•Large polypeptides = proteins

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Protein Structure

Amino acids chains will fold into:

1.Primary – sequence of amino acids

2.Secondary - ⍺ helix & β sheets

3.Tertiary – 3D shape

4.Quaternary – combined subunits

•7.5 Using Biochemistry to Identify Microorganisms

Using biochem to ID microbes

1.MALDI-TOF

matrix-assisted laser desorption/ionization

time-of-flight mass spectrometry

2.FAME

fatty acid methyl ester analysis

3.PLFA

phospholipid-derived fatty acids analysis

4.Proteomic analysis

5.Carbohydrate analysis