11 protein classification Flashcards
proteins comprised of only 1 type of amino acid is called a:
simple protein
a protein soluble in neutral, DISTILLED WATER
albumin
a protein soluble in neutral dilute SALT
globulin
a protein soluble in dilute acid or base
glutelin
soluble in alcohol (ethanol)
prolamines
insoluble in water and neutral salts
scleroproteins
basic proteins (contain a lot of lysine and arginine)
histones
food science is most interested in what classes of proteins?
albumins and globulins
conjugated proteins
contain chemical moieties other than amino acids
a non-amino acid component of a protein is called a:
prosthetic group
prosthetic groups include:
- lipoproteins
- glycoproteins
- metaloproteins
- phosphoproteins
carbohydrate usually attaches to OH group of what amino acids by O-glycosidic linkage?
threonine, serine
carbohydrate usually attaches to amide group of what amino acid by N-glycosidic linkage?
asparagine
what’s a metaloprotein?
protein mixed with metal ion that’s loosely chelated
give 2 examples of metaloproteins
hemoglobin and myoglobin - they chelate Fe2+ in porphoryn rings
numerous ______ have metal ions as their prosthetic group
enzymes
what’s a phosphoprotein?
proteins conjugated to inorganic phosphates
give examples of phosphoproteins
casein, rennin
P is linked to OH groups of ser and thr
denaturation disrupts what structures of a protein?
secondary and tertiary
denaturation:
change in structure or conformation that doesn’t involve breaking of peptide bonds
what are the interactions disrupted in denaturation?
- H bonds
- electrostatic bonds
- hydrophobic interactions
- van der waal’s forces
denaturation causes a lot of _______ properties to change
physical
denaturation generally (increases/decreases) water solubility?
decreases
denaturation can cause an (increase/decrease) in viscosity?
increase
denaturation (promotes/inhibits) crystallization
inhibits
what can occur if proteins are denatured to the point where their secondary structures are completely disrupted?
- polymerization or aggregation
leading to gel formation or precipitation
what factors influence denaturation?
- temp
- pH
- changes in ionic strength
- chemical agents
- surface forces
shift in pH effects which protein structure?
tertiary (electrostatic)
what is one substance used to compete with peptide linkage for H bonds? disrupts both tertiary and secondary structures
urea
