Base Pairing. The particular H-bonding taking place between purines and pyrimidines in dou-

44. Base Pairing. The particular H-bonding taking place between purines and pyrimidines in dou-

ble-stranded nucleic acids (i.e., DNA and RNA).

45. Batch Culture. A cell suspension grown in a liquid medium of a known volume. Organisms in this system invariably exhibit a ‘sigmoid’ type growth curve. The inocula of successive sub- cultures are of similar size, and the cultures usually contain almost an equivalent quantum of ‘cell-mass’ at the end of each passage. Cultures frequently exhibit five distinct phases per passage, namely : (i) lag phase ; (ii) exponential growth phase ; (iii) linear-growth phase ; (iv) deceleration phase ; and (v) stationary phase.

46. Bacteriostat. A chemical entity or other substance that does not kill but prevents the possible

bacterial growth and multiplication is termed as bacteriostatic.

47. Bactericide. An agent or a substance that usually kills bacteria (rather rapidly) ; and this activity is known as ‘bactericidal activity’.

48. Bioassay. A biological assay carried out on the ‘living cells’ or on a ‘living organism’.

49. Biochip. A hi-tech device that essentially combines a small scale ‘biosensor’ with an inte- grated circuit.

50. Bioconversion. The actual transformation of matter from one form to another by living organ- isms or enzymes.

51. Biodegradation. A recognized and accepted phenomenon whereby a material is broken down into its smaller chemical fragments by the action of living organisms e.g., biodegradable poly- mers, biodegradable packing components etc.

52. Biomass. The cell mass produced during fermentation or the total weight of living matter in a population.

GLOSSARY

53. Biopolymer. An altogether different type of large molecules duly formed by organisms i.e., nucleic acids, proteins, lipids, and polysaccharides.

54. Bioreactor. A vessel, preferably made up of SS, employed to perform a biological reaction i.e.,

a reactor used for the culture of aerobic cells, or to the columns or packed beds of immobilized cells or enzymes.

55. Biosensor. A highly specific and sophisticated device that usually makes use of an agent either having a biological origin or a biological principle, for the assay of a chemical compound viz., tissues, immunosystems, isolated enzymes, organelles, and whole cells as catalysts. The ‘catalyst’ is immobilized and used in conjunction with a physico-chemical device.

56. Biosynthesis. Refers to ‘biological synthesis’ i.e., the building or forming of biological compounds in a living organism.

57. Biotechnology. The meticulous application of organisms, biological systems, or biological phenomena specifically either to manufacturing units or to service industries. However, this very definition has been logistically extended to include any process or device wherein organ-

isms, tissue cells, organelles, isolated enzymes, design and usage of ‘bioreactors’, fermentors,

downstream processing, and above all the analytical and control equipment associated with biological manufacturing process.

58. Biotype. A certain group of organisms having the same genetic characteristic features.

59. Biotin [Vitamin H ; Co-carboxylase ; C 10 H 16 O 3 N 2 S ; MW 244.31] :

It is a component of vitamin B complex. It serves as a prosthetic moiety for carboxylase- enzymes. Usually present in all living cells bound to proteins or polypeptides, and is of utmost importance in carbohydrate, protein, and fat metabolism. It is essentially component of most plant tissue culture media.

60. Buffer. An admixture of various chemical substances (mostly inorganic) in an aqueous me- dium, or system that prevents/resists change in pH (despite addition of small quantum of acid or base) and withstand shock ; as buffered media can appreciably resist pH drift. The extent to which pH change can be resisted logically represents as a measure of the solution’s buffering

capacity.

61. Budding. A form of asexual reproduction wherein a daughter cell develops from a small out- growth or protrusion of the mother (parent) cell.

62. Callus (plural-calluses or calli). An actively growing undifferentiated (parenchymous) tissue formed in higher plants in response to wounded surface or certain infections. It usually repre- sents a disorganized tumour-like masses of plant cells which are formed in a culture medium. It proliferates in an irregular tissue mass which varies extensively in several aspects e.g., appear- ance, texture, rate of growth. Callogenesis — refers to the phenomenon of callus formation i.e.,

a function of the tissue type (species and explant) as well as the composition of the medium.

63. Capsid. A protein coat of a virus enclosing the naked nucleic acid (i.e., DNA and RNA).

64. Capsomere. The individual protein subunits which essentially form the capsid of a virus.