Protein Flashcards
(26 cards)
What are proteins made up of?
Amino acid residues
Proteins are polymers similar to starch, which is made of glucose residues.
What is the protein equivalent of the glycosidic bond?
Peptide bond
A peptide bond is formed with the loss of a water molecule.
What are peptides?
Short chains of amino acids linked by peptide bonds
The term peptide is derived from the Greek word ‘peptós’, meaning digested.
What do we call chains of two and three amino acid residues?
Di and tri peptides
What are oligopeptides?
Chains of amino acid residues up to ten
What is a polypeptide?
A continuous chain greater than ten (sometimes greater than 15) amino acid residues
What are the two distinct ends of an amino acid chain called?
N-terminus (amino end) and C-terminus (carboxyl end)
What elements do proteins contain besides carbon, hydrogen, and oxygen?
Nitrogen and sulphur
How many amino acid residues does a molecule usually need to be considered a protein?
More than 50 amino acid residues
What is the largest known protein?
Titin
How many amino acid residues does Titin consist of?
34,351 amino acids residues
What are the four levels of protein structure?
Primary, secondary, tertiary, and quaternary structures
What defines the primary structure of a protein?
The sequence of amino acids held in place by peptide bonds
What are common secondary structures of proteins?
ɑ-helix and β-strand or sheet
What stabilizes the secondary structure of proteins?
Hydrogen bonds
What does the tertiary structure of a protein refer to?
The spatial arrangements of the components of the secondary structure
What interactions stabilize the tertiary structure?
Non-covalent interactions, disulphide bonds, and metal ion coordination
What is the quaternary structure of a protein?
The number and arrangement of protein subunits often in association with other molecules
What are some classifications of proteins?
Structure, function, location, and properties
What are glycoproteins?
Proteins associated with carbohydrates
What are lipoproteins?
Proteins associated with lipids
What are metalloproteins?
Proteins associated with metal ions
What is the main role of proteins in mashing?
To catalyse the hydrolysis of mashing substrates
What is an example of an enzyme used in mashing?
α-amylase
