Computerized biology laboratory works

O.A. Povalyaev - Chief of the "SNARK" research group, candidate of technical sciences
E.N.Ovcharova - Biology teacher of the secondary school #880, candidate of biological sciences
L.I. Rubacheva - Manager of the MIPKRO teaching and methodical laboratory

The laboratory operations are extremely important part of educational process when biology is studied in school. Therefore each teacher aspires to make their maximum informative and attractive for the pupils. Certainly, the computer can help with it. Pupils get acquainted with computer abilities both at lessons of computer science in school and in private life. The computer comes to them as an element of show business (e.g. computer games). Pupils get acquainted and with other opportunities of a computer at the lessons of computer science. They learn about drawing up various archives and databases (original "notebook"), performance of the composite evaluations ("calculator"), text editing. Thus, pupils have an impression that a computer is either a toy, or the advanced writing accessories. Of course, both of these applications are extremely important and literally have made revolution as in the field of entertainments and in the office-work, but computer opportunities are not limited by it. The series of the computerized laboratory operations, created by the SNARK research group and by the MGIU laboratory of new training technologies in cooperation with the Moscow professional development institute for educational employees (MIPKRO), uncloses computer opportunities for processing analogue signals (i.e. signals from actual physical devices) to the pupils. This aspect of computer application is extremely important for future doctors (the modern diagnostic methods), for processing engineers (industrial process control), and also for researchers, military, designers and for representatives of other specialities, who depend on the natural sciences at performance and subsequent mathematical processing of the physical quantities measurement result. But, unfortunately, this aspect of computer application in a school course of computer science is not practically considered. The computerized laboratory works in the field of natural sciences, particular in biology are called to liquidate this gap. Indisputable advantage of this series of laboratory works is the obviousness for the pupils of interior system of such major optical devices as spectrophotometers, photoelectrocalorimters, polarimeters, nephelometers and luminometers for carrying out of biological research of the optical instruments. In fact all these devices consist of the combination of the light source, the light receiver and additional filtering light elements. All these elements are executed as separate small blocks as in a laboratory complex designed, which are easily installed on the magnetic blackboard. A pupil can assemble any necessary optical instrument necessary from these blocks as from cubes. Here intersubject ties are occurred: the pupil at practice understands that optics laws, which he studied in physics course, are the major studying tools of the biological phenomena. The analogue signal from the device translates in a digital form and transmits to a computer with the help of analog-digital transformer (ADT). It uncloses ample opportunities for measurement result processing: build-up of diagrams, statistical result processing, and an simultaneously tracking opportunity for several parameters which relations can be shown not only as diagrams, and as tables. The laboratory works for studying properties of monosaccharides, fibers and enzymes ("Cytology" section of general biology course are constructed; 1 half-year of 10 class), and growth curves of microorganisms (11 class, ecology) are based on optical parameter measurement. Monosaccharide laboratory work allows to acquaint pupils easily in practice with existence of sugar optical isomers. Intersubject ties not only with physics (assembly of polarimeter laboratory model circuit), but, first of all, with chemistry are obvious in this work. However chemical properties of sugars (and others biologically active substances) are considered in organic chemistry course very briefly as the attention of organic chemist first of all focused on oil processing products and regenerated polymer compounds gained on their basis.

At the same time for the biologist monosaccharides are the base of such major part of a metabolism as an energy metabolism and a carbohydrate metabolism cycle is a key uniting an energy metabolism with plastic in a single whole. Thereof it is better to carry out works on monosaccharide studying in the cytology course (10 class) as an illustration to the "Carbohydrates" section. Also laboratory work at egg albumin denaturation studying is very interesting. In the work given the light diffusing is measured on laboratory installation. For albumin light diffusing the temperature effect diagram, gained on measurement results, allows to show evidently for a pupils not only typical for most proteins the denaturation temperature range, but also to show as far as promptly nonreversible protein denaturation comes at excess of a critical temperature threshold. A series of laboratory works at studying of response rate of the enzymatic reaction are interesting by allowing to fix an enzymatic reaction flow (starch digestion by amylase) at a neutral mode. Measurement process is extremely toilful at the periodic mode, but becomes so easy feasible at the continuous monitoring, that a teacher without any problems can carry out not only studying of individual enzymatic reaction kinetics in the fixed conditions, but also to trace influence on enzymatic reaction rate of such factors, as enzyme concentration, temperature, medium acidity with a pupils. The opportunity to trace growth dynamics of microorganisms (for example, yeast) in the continuous mode and thus to receive the actual S-shaped curve which for the most pupils always remains only abstraction, represents the great cognitive meaning, given by this work cycle. So, the series of laboratory works for senior classes has important developing and cognitive meaning. The works of the "Man and health" course for 9-form classes are not less interesting. Pupils are evidently convinced that physiological parameters of organism are also measured with the help of physical devices. Pupils can trace respiration rate and compare the individual data to the data of other pupils and to the average values given in the textbook in the laboratory works with respect to breath; they can analyze physical and emotional activity influence on respiration rate, can be convinced that human speech sounds arise only from the exhalation, also they can analyze breath-holding influence on inhalation and exhalation depths (to the question about respiratory movement regulation). Pupils can compare inhaled and exhaled air moisture (air moisture always is close to 100 %, because alveolus should not dry up!) and also to compare evaporating rate of moisture from the surface of skin and lungs with the help of moisture sensor. "Nervous system" works allow not only to establish individual distinctions between pupils in nervous response rate (simple sensomotor test), but also to trace influence of such factors, as derivation of attention and intoxication incipient at breath-holding, on this rate results. More complex nervous process (response with a select) is simultaneously shown. The emotional state exerts influence on its rate, in particular so-called "order - readiness to performance of particular activities and object achievement. So, this computerized laboratory work course extends pupil conceptions about computer abilities. They also get acquainted with general system principles of optical devices and physiological sensors, and developing intersubject ties in their own thinking. The considerable labor reduction, due to their performance in the continuous mode, uncloses ample opportunities of process analysis, which were inaccessible early to the school biology course. As a whole the suggested laboratory works extend and intensify theoretical knowledge of pupils and their practical skills and promote pupil's liberalizing and their natural-science ideology building.