Biochem Lec Mid

• β-amino isobutyric acid: End product of pyrimidine metabolism.
• Learners should be able to classify each amino acid based on the structural differences of its side chain (nonpolar, polar, uncharged, acidic, and basic).
• Proteins are polymers of amino acids joined by specific covalent bonds.
• Amino acids can be classified into four major groups based on their R group.
• Learners should be able to give the name and formula of an amino acid.
• Learners should be able to calculate the isoelectric pH.
• Learners should be able to show the ionization of a given amino acid in a diagram.
• Learners should be able to define a peptide bond.
• Learners should be able to describe the chemistry of a peptide bond.
• Polypeptide chains have specific structures.
• Small peptides with physiological activities include Gluthathione, Aspartame, Oxytocin, and Vasopressin.
• Amino acids are the building blocks of proteins and determine their biological activity.
• Growth, repair, and maintenance of cells depend on amino acids.
• Proteins catalyze reactions and control cellular processes.
• Proteins are naturally occurring, unbranched polymers made up of amino acid monomer units.
• Proteins are the most abundant molecules in cells after water, accounting for about 15% of a cell's overall mass.
• There are twenty different amino acids commonly found in proteins.
• Asparagine was the first amino acid to be discovered in 1806, while threonine was the last to be identified in 1938.
• Amino acids have trivial or common names, often derived from the source from which they were first isolated.
• Examples include asparagine from asparagus, glutamate from wheat gluten, and tyrosine from cheese.
• Glycine was named for its sweet taste, derived from the Greek word for "sweet" (glykos).
• Carbon (C), Hydrogen (H), Nitrogen (N), Oxygen (O), and Sulfur (S) are present in amino acids.
• Iron (Fe), phosphorus (P), and other metals may also be present in specialized proteins.
• The basic structure of amino acids is common to all except for the cyclic amino acid, proline.
• Each amino acid has a different side chain (R group) attached to the α-carbon.
• Amino acid symbols are used to indicate the composition and sequence of amino acids in proteins.
• Carbon atoms in amino acids are identified using a numbering system, with the highest priority given to the carbon with the substituent containing the atom of highest atomic number.
• All 20 common amino acids are α-amino acids, with a carboxyl group and an amino group bonded to the same carbon atom (the α-carbon).
• Amino acids differ from each other in their side chains, or R groups, which influence their solubility in water.
• For all common amino acids except glycine, the α-carbon is bonded to a carboxyl group, an amino group, an R group, and a hydrogen atom, making it a chiral center.
• Amino acids have two possible stereoisomers due to the arrangement of the four different groups around the α-carbon atom.
• Glycine is the only amino acid where the R group is a hydrogen atom.
• Cysteine is an example of an amino acid with a polar, uncharged R group, containing a sulfhydryl group.
• Cysteine can readily dimerize and form cystine through the reaction with another cysteine molecule, forming a covalent disulfide bond.
• Amino acids can have positively charged R groups, with the nitrogen atom of the amino group accepting a proton.
• Amino acids can also have negatively charged R groups, with the carboxyl group losing its acidic hydrogen atom.
• Aromatic R groups are a type of R group found in certain amino acids.
• Common names and three-letter abbreviations are used for naming amino acids, except for asparagine (Asn) and glutamine (Gln).
• Isoleucine (Ile) and tryptophan (Trp) are amino acids.
• One-letter symbols are commonly used for comparing amino acid sequences of proteins, with the most abundant amino acid getting the first letter if multiple amino acids have the same letter.