Organic Compounds: Amino Acids, Peptides, and Proteins

First published at 17:02 UTC on May 9th, 2024.

In this video I go over amino acids, which are derived from ammonia and carboxylate, and combine together to form peptides or longer chains as proteins. Amino acids combine via peptide bonds, which are covalent bonds that involve the loss of a water molecule. Thus, technically, peptides and proteins are made up of amino acid residues, indicating they are formed from the "residue" or leftover molecules in the peptide bond reaction (since water is lost). Further terms and definitions are listed in the timestamps below.

Timestamps:

- Ammonia (NH3) is a compound of nitrogen and hydrogen: 0:00
- Amines have a basic nitrogen atom with a lone pair of electrons: 1:09
- Amino group is the substituent -NH2: 2:25
- Amino acids contained charged amino (ammonio), carboxylate, and a side chain: 3:05
- Every amino acid contains carbon, hydrogen, oxygen, nitrogen: 4:20
- Structure of generic L-amino acid used for systematic naming: 4:45
- L- vs D- amino acids are left and right handed (chiral) configurations: 5:21
- A molecule or ion is chiral if it can't be superposed on its mirror image by any combination of rotations, translation, some conformational changes: 6:30
- A chiral molecule or ion exists in 2 stereoisomers that are mirror images, called enantiomers: 7:14
- Peptides are short chains of amino acids linked by peptide bonds (covalent bond that releases a water molecule): 8:36
- Oligopeptide consists of 2 to 20 amino acids: 9:44
- Polypeptide is a longer continuous unbranched peptide chain: 10:08
- Protein is a polypeptide with more than approximately 50 amino acids: 10:22
- Proteins consists of 1+ polypeptides arranged in a biologically functional way: 11:09
- Ligand forms a complex (surrounding a central atom or ion) with a biomolecule: 11:39
- Cofactor is required for an enzyme's activity as a catalyst (increases rate of reaction): 13:08
- Amino acid residues refer to the amino acids left over from peptide bonds which removes a water molecule: 13:51
- Condensation reaction combines two molecules into one: 15:54
- Protein sequence is the linear sequence of amino acids, reported from amino-terminal (N) end to carboxyl-terminal (C) end: 16:02