Classification of protein based on shape, Biology

Protein Classification Based on Shape

There are three types of proteins on the basis of shape - Fibrous, Globular, Intermediate

1.       FIBROUS PROTEINS

  1. They are thread-like elongated proteins which have little or no tertiary structure.
  2. Secondary structure in the final structure in fibrous proteins.
  3. All the three types of secondary structure occur in fibrous proteins.
  4. Fibrous proteins occur singley or join together in coils and bundles to form fibres.
  5. They are nonenzymatic proteins which are insoluble in water, produce structural components, provide rigidity and elasticity.
  6. Common fibrous proteins are collagen (connective tissue, tendon, cartilage, bone teeth), keratin (skin, hair, beaks, feathers, claws, nails, hoofs, horns), fibroin (silk, spider webs), elastin, tropomyosin, paramyosin, fibrin (blood clot), etc.

2.       GLOBULAR PROTEINS

  1. They are rounded, over or oblong in outline.
  2. The shape is achieved through tertiary and quaternary folding of polypeptides.
  3. Most of the proteins are globular in nature.
  4. They are not contractile but otherwise from all other types of proteinaceous structures, both enzymatic and non-enzymatic (including antibodies and hormones).
  5. Their solubility in water depends upon size.
  6. Smaller globular proteins are soluble in water.
  7. They are also not coagulated by heat, e.g., histones.
  8. With increase in size the globular proteins become sparingly soluble in water and develop the tendency to get coagulated by heat.
  9. Albumins are soluble in water but are coagulated by heat, e.g., egg albumin. Globulins (e.g., Serum globulins) and glutenins (e.g., Wheat, Maize) are both insoluble in water and coagulate with application of heat.

3.       INTERMEDIATE PROTEINS

  1. They are neither fibrous nor globular but of intermediate from and characteristics.
  2. Myosin with some 1700 amino acid residues in its polypeptide is not fibrous but assumes an extended from in solution.
  3. Fibrinogen is a highly soluble extended but somewhat asymmetric protein that forms insoluble fibrin in coagulated blood.
Posted Date: 10/9/2012 5:57:04 AM | Location : United States







Related Discussions:- Classification of protein based on shape, Assignment Help, Ask Question on Classification of protein based on shape, Get Answer, Expert's Help, Classification of protein based on shape Discussions

Write discussion on Classification of protein based on shape
Your posts are moderated
Related Questions
Explain in detail about the Concomitant squint Concomitant squint is also called comitant squint. It means "I follow you", i.e., in all directions of gazes, the squinted eye fo

A container is filled to a depth of 20.0 cm with water. On top of the water floats a 30.0-cm-thick layer of oil with specific gravity 0.700. What is the absolute pressure at the bo

Explain the Properties of Good Prebiotic? Thus, to summarize, we can say that a good prebiotic should have the following properties: Be active at a nutritionally feasibl

Define the Carbohydrate and Fat required for elderly? Carbohydrate: It is usually recommended that approximately 55en% (percent of  energy) be provided from carbohydrate food

How do you determine if a molecule is polar or non-polar? A polar molecule is a molecule that has a net dipole moment because of its having unsymmetrical polar bonds

Q. What is the difference between the concepts of genome and karyotype? Genome is the set of DNA molecules that characterizes each species or each living being. The concept the

Q. What are the Symptoms of dyslipidemia? The main symptom is presence of xanthoma: This is a yellowish swelling, nodule or plaque in the skin resulting from deposits of fat. T


Was there molecular oxygen in the earth's primitive atmosphere? How has that molecule become abundant? The presence of the molecular oxygen in the primitive atmosphere was prob

Q. How does the breathing process correct alkalosis? If the body undergoes alkalosis the respiratory center located in the medulla gets the information and induces the lowering