Biological Compounds

There is a difference between an element, a molecule, and a compound.

  • An element is one type of atom (H, for example).

  • A molecule is two or more elements of the same type chemically bonded (O2, for example).

  • A compound is two or more elements of different types that are chemically bonded (CO2, for example).


Miller-Urey Experiment

This experiment set out to replicate conditions of the early Earth to see if life-necessary amino acids would form naturally. It was a success.

The experiment used Methane (CH4). Carbon makes methane easily because it has 4 valence electrons, and Hydrogen only has one. Elements like to have electrons add up to 8.

Since carbon is so good at bonding, it’s an integral part in many important molecules.

Functional Groups

Functional groups are sort of “suffix” compounds. They all have sides open for bonding. They can add polarity to a compound. Polarity is important because it makes solubility possible. The compounds are:

  • Hydroxyl (-OH)

  • Carbonyl (>C=O)

  • Carboxyl (-COOH)

  • Amino (-NH2)

  • Sulfhydryl (-SH)

  • Phosphate (-OPO3^2-)

  • Methyl (-CH2)

They show up in 3 of the major biomolecules.

Acid-Base Theories

There are different theories of how H+ transfers between acids and Bases.

Brønsted-Lowry theory says that acids give the H+ and bases receive H+.

Lewis theory says that bases give the H+ and acids receive it.

Salts and Buffers

In a Buffer, acids and bases neutralize each other. Salts exist because of this process. There is a bicarbonate buffer in blood that does this. Buffers have been used in lakes in New York to help with pollution that makes a lake acidic.

Four Major Biomolecules

The four major biomolecules are

  • Lipids, which do energy storage and insulation

  • Carbohydrates, which provide rapid energy and structure

  • Proteins, which help with enzymes, structure, and transport

  • Nucleic Acids, which store and send genetic information


Lipids

Lipids are macromolecules made of fatty acid monomers, not polymers. They are hydrophobic. They can exist as Triglycerides, Phospholipids, and Steroids/Waxes

They also help make up cell structure, store energy, and cell signalling.

Hormones tell the tissue to do something.

Essential Fatty Acids include Omega-3 and Omega-6.

Acids and Vitamins include the fat-soluble vitamins A, D, E, and K, while water-soluble vitamins include B-complex and C. Vitamins help with metabolism and immune function.

Carbohydrates

Carbohydrates can exist both as monomers and polymers, unlike lipids. Monosaccharides and Polysaccharides are monomers and polymers, respectively. Glucose is an example of a monosaccharide, while starch is an example of a polysaccharide.

The ratio of elements in a carbohydrate is C:H:O = 1:2:1

Proteins

Amino Acids are an example of a protein monomer. Each type of amino acid has its own unique R-Group.

Proteins can make Polypeptides via bonding with peptides.

Once bonded, Proteins can be part of 4 levels of bonding:

  • Primary, which looks like a string of beads. This is the structure amino acids have.

  • Secondary, which is known as an alpha-helix or beta-pleated sheet.

  • Tertiary, which can show up as Fibrous or Globular. These are 3D shapes.

  • Quaternary, which involves multiple polypeptide chains.


Nucleic Acid (DNA and RNA)

Unlike DNA (deoxyribonucleic acid), which uses Adenine, Guanine, Cytosine, and Thymine (Think Gattaca), RNA (ribonucleic acid) uses Uracil instead of Thymine.

As a monomer, it is a Nucleotide, made of sugar, phosphate, and a base.

Prions

Prions (Proteinaceous Infectious Particle) are misfolded proteins that cause disease. Some examples of Prion diseases are Mad Cow Disease, Chronic Wasting Disease, and Creutzfeldt-Jakob Disease.

They have no unique genetic material and have ongoing research dedicated to them. They merely influence and pull apart other proteins in important areas like the brain and nerves.