Packet #13 Flashcards
zwitterion
amino acid in the form that has a negatively-charged carboxylate group on one end and a positively charged ammonium group on the other.
zwitterion + acid
amino acid cation + water
zwitterion + base
amino acid anion + water
How to make a dipeptide
- -OH group from carboxylic acid end of first amino acid and a -H from the amine end of the other amino acid
- needs strong acid catalyst
- results in a dipeptide.
- bond between the carbonyl C and the -N is a peptide bond
primary protein structure
- the sequence of amino acid residues in a protein
- Example: Gly-Ser-Gly-Ala
Secondary protein structure
- this refers to whether a segment of a protein chain is coiled into a helix or whether the chains are stacked more straightly into sheets
- alpha-helix
- beta-sheets
Tertiary protein structure
Refers to how several helical segments or sheet segments of the same polypeptide chain are arranged in space relative to each other
Quaternary protein structure
Some proteins are made up of more than one polypeptide chain. Quaternary structure refers to how the separate chains are arranged in space relative to each other
protein definition
a polypeptide that has a specific sequence of amino acid residues and does a specific job in the body.
amino acid residue
when amino acids combine they are amides so they can’t be called an amino acid; called amino acid residues.
amyloidosis
a disease characterized by the presence of amyloid proteins (Alzheimer’s abd Creutzfeld-Jakob Disease)
amyloid
a protein that is normally alpha-helical BUT has been misfolded into a ß-sheet
protein jobs
- structure (keratin & collagen)
- catalys (lactase, sucrase, pepsin. . .)
- muscle contraction (actin & myosin)
- transport & storage (hemoglobin & myoglobin)
- immune system (antibodies)
