NEET Biology Solved Question Paper 2006

In fibrinolysis, a fibrin clot, the product of coagulation is broken down. Plasmin is a proteolytic enzyme in plasma which can digest many proteins through the process of hydrolysis. It cuts the fibrin mesh at various places, leading to production of circulating fragments which are cleared by other proteases or by the kidney and liver. It induces lysis of fibrin during fibrinolysis and is known as fibrinolysin

Amino acid is the monomer unit of protein. Glycine is the simplest amino acid as it contains one amino group and one carboxylic group. The structural formula of Glycine is 

Mitochondria and chloroplast contain DNA. The extranuclear inheritance or cytoplasmic inheritance is a consequence of the presence of genes in mitochondria and chloroplasts.

The principal of carbohydrate in diet is starch i.e., the carbohydrates, ingested in the diet, are hydrolyzed by the enzyme called $\mathrm{\alpha }$-amylase. This enzyme is found in saliva and intestinal juice. It's main function is to break down glycosidic bonds between glucose units.

Pepsin is an endopeptidase that breaks down proteins into smaller peptides. It is produced in the stomach and is one of the main digestive enzymes in the digestive systems of humans and many other animals.

Cellulose is the main constituent of cell wall in plants. It provides rigidity or stiffness to plants. It is the abundant organic compound on Earth.

Glucosidases are enzymes involved in breaking down complex carbohydrates such as starch and glycogen into their monomers. Their main function is to catalyze the cleavage of individual glucosyl residues from various glyco- conjugates including alpha or beta linked polymers of glucose.

Stomach is the site of digestion mainly for proteins and fats. Proteins are very complex organic molecules having amino acids as monomer units. They consits of Carbon, Hydrogen, Oxygen and Nitrogen. They also consists of less amount of sulphur, phosphorus, iodine and iron.

Lipid is a term used to describe a group of substances in cell, characterized by their solubility in organic solvents such as ether and benzene. These are insoluble in water, because they contain hydrophobic fatty acid chain.

Smooth endoplasmic reticulum or SER forms transport vesicles by which large molecules are moved in the cell. Often transport vesicles are on their way to the plasma membrane or another part of the endomembrane system particularly the Golgi apparatus.

Prokaryotes are unicellular or multicellular organisms. These lack true nucleus, nuclear membrane and membrane bound organelles such as mitochondria, Golgi bodies, lysosomes etc. It also lacks Endoplasmic reticulum or ER.

Lysosomes may be formed directly from endoplasmic reticulum (ER). Enzymes are stored within the lysosomes as crystalline form mainly as hydrolytic enzymes. These enzymes are synthesized on RER. These enzymes help in the digestion if required.

Prokaryotic cell consists of a small amount of genetic material in the form of a single molecule or chromosome of circular DNA. It lies in the centre of a single chromosome. Hence, it is known nucleoid or genophore.