Study Set Content:
antibodies - counteract the foreign protein; fibrinogen – blood clotting
Protection
some proteins not only control gene expression, thereby regulating the kind of proteins synthesized in a particular cell, but also dictate when such manufacture takes place.
Regulation
Molecules are constituted by several coiled cross-linked polypeptide chains
Fibrous proteins
• Insoluble in water and highly resistant to enzyme digestion
Fibrous proteins
Soluble in water
Globular proteins
Constitute the enzymes, oxygen-carrying proteins, hormones
Globular proteins
serve as structural entities
Fibrous proteins
the major protein of the connective tissue, insoluble in water, acids or alkalis; convertible to water-soluble gelatin, easily digestible by enzymes
Collagen
protein of hair, nails
Keratins
present in tendons, arteries and other elastic tissues, not convertible to gelatin.
Elastins
- is a protein in which only amino acid residues are present (e.g.insulin, oxytocin)
• Simple protein
- is a protein that has one or more non-amino acid (prosthetic group) entities present in its structure in addition to one or more peptide chains
Conjugated protein
• Upon hydrolysis, yields the
prosthetic group
• prosthetic group could be a
sugar, nucleic acid, lipid or some other group
Soluble in water; Coagulated by heat
Albumins
Insoluble in water; Soluble in dilute salt solutions; coagulated by heat
Globulins
Insoluble in water or dilute salt solution; soluble in dilute acid or alkali
Glutelins
Insoluble in neutral solutions; soluble in 80% alcohol
Prolamines
Dissolved only by boiling In acids
Albuminoids
Soluble in water Insoluble in dilute ammonia Basic in reaction
Histones
