Organic Chemistry

Monomers and Polymers

Attribution: K.R Roshith, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Polymers are large molecules made up of repeated units of smaller molecules called monomers. Think of links on a chain. The monomers are the individual links and the polymer is the entire chain. The process by which monomers bond is called polymerization. Watch the following video:

https://youtu.be/6tSIbSKacXA

How Can Polymers Be Classified?

A polymer can be:

Homopolymers: Consist of 1 type of monomer.
Copolymers: Consist of 2 or more types of monomers.

Homopolymer: nine blue circles connected; Copolymer: a chain of circles connected in the following order: blue, two orange, blue, orange, three blues and orange.

A polymer can be either straight (linear) chain, or branched.

There are two structures. Straight which has four carbons connected by single lines. The first and last carbon are attached to three hydrogens and the two middle carbons are attached to two hydrogens. The branched structure is a carbon attached to three carbons. The central carbon is attached to one hydrogen. The other three carbons are attached to three hydrogens.

Additionally, polymers are not just made from oil-based compounds (i.e. plastics), they are also made of living things.

Examples: Proteins, carbohydrates, lipids, nucleic acids
Polylactic acid is made by polymerizing lactic acid produced by bacteria
Some plants can be genetically engineered to produce bioplastics

Biopolymers are renewable resources, and are easily degradable, so these are preferable to oil based polymers when possible.

What Are Hydrocarbons?

When discussing hydrocarbons, there is some key terminology we need to review:

Covalent Bond: 2 or more nonmetals sharing valence electrons.
Organic Chemistry: The study of carbon based compounds.
Organic Compounds: Compounds that contain carbon.
There are three types of bonds: Single bond, double bond and triple bond.

Single Bond: A single line connecting two hydrogens; double bond: two lines connecting two O's; Triple bond: Three lines connecting two N's.

A hydrocarbon is an organic compound that consists primarily of hydrogen and carbon, and there are four classes of hydrocarbons which are the following:

Alkanes consists of only single bonds, such as C-C, example is Methane (CH4) and a model is four carbons connected with single bonds. Alkenes have at least one double bond, such as C=C, ethene (C2H4) is an example, and a model is 4 carbons connected with one double bond. Alkynes have at least one triple bond, such as a C connected by three lines to another carbon. Butyne (C4H6) is an example. A model is four carbons connected with one connection having a triple bond. Cyclic Hydrocarbons are ringed structures with single bonds. An example is cyclohexane (C6H12). A model is four carbons connected in a square structure.

Many organic compounds contain atoms other than carbon and hydrogen. These groups are called functional groups. Functional Groups are a specific arrangement of atoms in an organic molecule and are very important for determining the reactivity of an organic molecule. There are many functional groups which you can attach to the carbon chain, but you only need to know the following ones:

Hydroxyl (-OH)

R with one line going to an O with a line going from the O to an H.

Aldehyde (C=O)

A central carbon with two lines going towards an O, one line going to an R, and one line going towards and H.

Carboxylic Acid (COOH)

A central carbon with two lines going to an O, one line going to an R, and one line going to an OH.

Watch the following video!

https://youtu.be/9lpPEOA1gIM

Hydrocarbons have isomers. An isomer is when you have hydrocarbons with the same number of atoms, but a different shape. As you increase the number of carbon atoms in a hydrocarbon, the number of isomers quickly increases due to the greater number of possible arrangements. Next, isomers have different properties. For example, Isomers will have different boiling points because the different shapes of the isomers will create different intermolecular forces between molecules; thus, affecting the boiling point. As carbon chains grow longer there is an increase in the intermolecular forces of attraction between molecules, such as the London Dispersion Forces. These forces hold molecules together, and in order to boil, the molecules must be separated. So, if there are stronger intermolecular forces of attraction between molecules as the number of carbons in a chain increases, the boiling point will also increase.

What Are The Biomolecules?

Watch the following video:

https://youtu.be/YO244P1e9QM

This is a 3 by 5 table with the following labels: Biomolecule, Monomer, Polymer. The first row is carbohydrates, Monosaccharide (Simple Sugar), and Polysaccharide (Complex Sugar) AND Disaccharides: row two is proteins, amino acids, and polypeptide: row three is lipids, fatty, Glycerol, and Fats, Oils, Steroids' and Waxes; Row four is Nucleic Acids, Nucleotides, and DNA and RNA.

Carbohydrates: These are what we think of as sugars and starches (polysaccharides)
- Carbohydrates are the main source of energy for the body
  - Even if you eat a bunch of fat and protein, these are turned into carbohydrates by your body, so they can be used by your cells.
- Some types are also used for structure and support, especially in plants
- 3 categories of carbohydrates
  - Monosaccharides: These carbohydrates have single ring structures. For example, glucose, galactose, and fructose.
  - Disaccharides: Two monosaccharides combine to form a disaccharide. For example, maltose, lactose, and sucrose.
  - Polysaccharides: Consists of 3 or more monosaccharides bonds together. For example, cellulose and glycogen.
Lipids have many function in the body and more energy is stored in 1 gram of fat than carbohydrates or proteins.
- Includes such things as: fats, oils, and waxes
- Types of fats:
  - Triglycerides: Fats and oils that store energy. They can be saturated or unsaturated.
  - Phospholipids: They make up the cell membrane, and they have a hydrophilic (water loving) and a hydrophobic (water fearing) part.
  - Cholesterol (steroids): Has a role in the structure of the cell membrane and synthesis of hormones.
  - Waxes: There are three types:
    - Spermaceti which is found in the head cavities of the sperm whale
    - Beeswax which is a natural wax produced by honey bees of the genus Apis.
    - Carnauba Wax which is a wax of the leaves of the palm Copernicia prunifera.
Proteins
- Proteins have the following functions:
  - Structure
  - Enzymes: catalysts that speed up chemical reaction
  - Transport: hemoglobin in blood transport gases
  - Toxins: many toxins/venom are proteins
  - Messages: Some hormones are proteins

Protein:
- Monomer= Amino Acid
  - The “R” group gives each amino its unique properties
  - ONLY the “R” group (side chain) is different, everything else is the same

Dipeptide= 2 amino acids bonded together
Polymer (Polypeptide)= Complete protein
A peptide bond links amino acids together
A total of 20 amino acids

A central carbon connected to an R, H, COOH and NH2

Watch the following video.

https://youtu.be/stR6RWIonf4

Nucleic Acids
- Nucleotides:
  - Consist of 3 parts: a sugar, a phosphate group, and a nitrogenous base
    - Nitrogenous Bases
      - Adenine (A)
      - Guanine (G)
      - Thymine (T) - DNA
      - Cytosine (C)
      - Uracil (U) –RNA
- Two nucleotides join together by a condensation reaction
- Polymer – Nucleic Acid
- 2 types of nucleic acids:
  - DNA and RNA: DNA is a double helix, RNA is a single helix molecule.

Watch the following video from 0:00 to 1:54:

https://youtu.be/MA-ouz1LtpM

Organic Chemistry​

Monomers and Polymers

Organic Chemistry