Synthesis

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Soaps and Detergent Synthetic polymers Proteins (Natural polymers) Empirical formulae “Synthesis”

Soaps and Detergents

• Fats and oils: long chain carboxylic acids are known as “fatty acids” will undergo reactions with glycerol to form fats and oils
• Glycerol: 3 hydroxyl groups on it
• Alcohol + acid will produce esters
• Fat: animal (saturated)
• Oil: plant
• “there are 5 kingdoms. animals, vegetables…” - norrie
• Acid ion makes soaps work
• Heat esters with hydroxide ions
  • you get glycerol back
  • you get 3 acid ions back
• For big organic ions, sometimes write with charges on individual ioons

1. soap or detergent dissolves in water
2. Surfactant ions orientate themselves in grease and water
3. Agitation begins to separate grease from surface
4. Process continues
5. Cleaning complete

• Soaps will precipitate with group 2 ions to form scum
• Detergents will not form scum

Polymers

• Long molecules - form plastics, synthetic fibres, etc
  • has 1000s of C’s
• Addition:
  • With alkene, double bond breaks
  • Monomers join up
  • Long chain alkane forms
  • Called a polymer
  • E.g. monomer + propene → polypropene
• Properties
  • Density: high for long strands
    • Low for branched molecules
  • Cross linking
    • Strands bonding(strong) molecules together
• Teflon
  • C2F4
  • Unreactive
  • Impervious to water
  • Non stick cookware
  • Plumbing tape
• Condensation
  • Esterification
  • 2 monomers

Amino Acids

• Amine and acid groups are on the same carbon
• R is a C chain + functional groups (side group)
• Acid end can act as acid
• Amine end can act as base
• 4 possibilities
  • Amine end has accepted proton and become positive, without acid donating proton
    • Acidic
  • Acid end has donated proton, without amine accepting proton
    • Basic
  • Both a positive and a negative charge
    • Neutral
  • Neutral molecule
• Can act as a buffer
• Condensation reactions; polymerisation

Polypeptides

• A polypeptide is a polymer of amino acids connected in a specific sequence
• Amino acids consist of 4 components attached to a centra carbon, the alpha carbon 🐺🐺🐺🐺🐺🐺🐺
• These components include a hydrogen atom, a carboxyl group, an amino group, and a variable R group (or side chain)
  • Differences in R groups produce the 20 different amino acids
• The 20 different R groups may be as simple as a hydrogen atom (as in the amino acid glutamine) to a carbon skeleton with various functional groups attached
• The physical and chemical characteristics of the R group determine the unique characteristics of an amino acid
• One group of amino acids has hydrophobic R groups (usually non-polar)
• Another group of amino acids has polar R groups, making them hydrophilic
• The last group of amino acids includes those with functional groups that are charged/ionised at cellular pH
  • Some R groups are bases, other are acids
• Amino acids are joined together when a dehydration reaction removes a hydroxyl group from the carbonyl end of one amino acid and a hydrogen from the amino group of another
  • The resulting covalent bond is called a peptide bond
• Repeating the process over and over again creates a long polypeptide chain
• A protein’s function determines by its specific conformation
  • Usually, it depends on its ability to recognise and bind to some other molecule
• Levels of protein structure
  • Primary structure
    • Unique sequence of amino acids
    • The precise primary structure of a protein is determined by inherited genetic information
    • Even a slight change in primary structure can affect a protein’s conformation and ability to function
    • Example: Sickle Cell Disease
  • Secondary structure
    • Results from hydrogen bonds at regular intervals along the polypeptide backbone
    • Typical shapes that develop from secondary structure are coils (an alpha helix) or folds (beta pleated sheets)
  • Tertiary structure
    • Used to organise the folding within a single polypeptide
    • Determined by a variety of interactions among R groups and between R groups and the polypeptide backbone
    • These interactions include hydrogen bonds among polar and/or charged areas, ionic bonds between charged R groups, and the hydrophobic interactions and Van der Wall’s interactions (dispersion forces) among hydrophobic R groups
  • Quaternary structure
    • Arises when two or more polypeptides join to form a protein
• A protein’s conformation can change in response to the physical and chemical conditinos
• Changes in pH, salt concentraiton, temperature, or other factors can iunravel or denature a protein
• Some proteins can return to their functional shape after denaturatino, but others cannot, especially in the crowded environment of the cell
  • Usually denaturation is permanent

Proteins

• Primary structure: sequence of amino acids
  • Order is important??????
• Secondary structure
  • Hydrogen bonds between peptide links (on backbone) cause folding
• Tertiary
  • Overall shape of proteins
  • Interaction of R groups (side groups)
  • Non-polar chains - dispersions with other non poilar groups
  • Polar: hydrogen bonding (betwen R groups)
  • Ionic bonding
• Fibrous vs globular
  • More strand like structural keratoi
• Denaturing
  • Disrupt the shape (uncoils)
    • H+ or OH- and heat
    • Breaks pH dependent links

Ethyl Ethanoate and friends

• Ethanol is created from hydration of ethene
• Ethanoic acid is created
• Ethanol + ethanoic acid → ethyl ethanoate

Haber process

• Hydrogen gas is produced from steam reforming and methane

$N_2+3H_2\rightleftharpoons 2N{H}_3\text{, }\Delta \text{H= -ve}$

• Iron/iron oxide catalyst (mesh)
• Temp 300-500˚C
  • Moderate temperature
  • Compromise between yield and reaction rate
• Constant removal of $N{H}_3$ (liquefy)
• Pressure of 100-250 atm
  • Very high pressure
  • Maximise yield and rate

Contact process (sulfuric acid)

• Source of sulfur is often from ore impurities like $Fe{S}_2$

$2S{O}_2+O_2\rightleftharpoons 2S{O}_3\text{, }\Delta \text{H= -ve}$

• Temp 400-50 ˚C
  • Moderate temperature
  • Compromise between rate and yield
• $V_2{O}_5$ catalyst
  • Vanadium pentoxide
• Pressure - Atmospheric pressure (1 atm)
  • Benefit to rate and yield is not worth the cost
• Strategic dissolving of $S{O}_3$

$\text{(Oleum) }{H}_2{S}_2{O}_7\to H_{2}S{O}_4+S{O}_3$

Enzymes

• Optimum temperature
• Functioning of Enzymes
  • related to side group and its acid/base behaviour
  • Change in R group alters interaction (COO- and COOH) and shape
  • Hydrolysis vs denaturation
    • Hydrolysis: breaking amide link on main chain
    • Denaturation: Change in shape conformation