chem

• A protein is a naturally-occurring, unbranched polymer in which the monomer units are amino acids. (contains 40 and up amino acids)
• monomer units of proteins are amino acids
• Elemental composition contains Carbon (C), Hydrogen (H), Nitrogen (N), Oxygen (O), most also contain Sulfur (S)
• COOH is the acid part; put at the top of the Fischer projection; attached to alpha carbon
• NH2 is the basic part, and the basis of L and D isomer; attached to alpha carbon
• R group or side chain is unique in every amino acid; located at the bottom of Fischer projection
• There are 20 standard amino acids; 19 are chiral
• Glycine is the only amino acid that is not chiral
• Zwitterion is an ion with + (positive) and – (Negative) charges on the same molecule with a net zero charge
• The number of isomeric peptides possible increases rapidly as the length of the peptide chain increases
• Cysteine is the only standard amino acid with a sulfhydryl group ( — SH group)
• Cystine are two cysteine residues linked via a covalent disulfide bond
• All of the other amino acid residues have names that end in -yl. The -yl suffix replaces the -ine or -ic acid ending of the amino acid name.
• Enkephalins are pentapeptide neurotransmitters produced by the brain and bind receptor within the brain and it helps reduce pain
• Glutathione protects cellular contents from oxidizing agents such as peroxides and superoxides; regulate the oxidation-reduction process
• Simple proteins is a protein in which only amino acid residues are present
• More than one protein subunit may be present but all subunits contain only amino acids
• Conjugated protein is a protein that has one or more non-amino acid entities (prosthetic groups) present in its structure
• Lipoproteins contain lipid prosthetic groups
• Glycoproteins contain carbohydrate groups
• Metalloproteins contain a specific metal as prosthetic group
• Primary Structure is the order and sequence of amino acids
• Secondary Structure is the backbone (alpha-helix – coiled; beta-pleated – folds)
• Tertiary Structure is a 3D structure and shows interactions
• Disulfide bond is the bond between two cysteine groups
• Electrostatic interactions is the bond between charged side chains like -OH, -NH2, -COOH
• H-Bonding bond with O, N or F
• Hydrophobic interactions it is between non-polar side chains
• Quaternary Structure is the combination of 2 or more subunits
• Non-polar amino acids are hydrophobic
• nonpolar amino acids consists of glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, and tryptophan
• polar amino acids are hydrophilic
• polar amino acids consists of serine, cysteine, threonine, asparagine, glutamine, and tyrosine
• Polar acidic is with carboxyl group
• polar acidic consists of aspartic acid and glutamic acid
• Polar basic is with amino group
• polar basic consists of histidine, lysine, and arginine
• fibrous proteins are alpha keratin and collagen
• Alpha-Keratin provides protective coating for organs
• Collagen is the most abundant proteins in humans (30% of total body protein); Organic component of bones and teeth