Fill in the gaps with the following words

introduced / entropy / added / reversible / in relation to / random / distribution / measures / density

______________ is a measure of the disorder of a system.

Light is refracted when it travels into a medium of different ______________.

The evolution of the eukaryotes ______________ several additional factors into the process of cell division.

Dolly established beyond all dispute that determination is ______________, that with the right techniques the fate of a fully differentiated cell can be altered.

The ______________ of individuals in a population can be clumped, random, or even.

Transposons select their new locations at ______________, and are as likely to enter one segment of a chromosome as another.

The inside of the cell is more negatively charged ______________ the outside.

In ATP the reactive group ______________ to the end of the AMP phosphate group is not another nucleotide but rather a chain of two additional phosphate groups.

A variety of defensive ______________ evolved in molluscs and gastropods, including thicker shells, spines, and shells too smooth for predators to be able to grasp.

Translate into Russian

1. If only a few factors of each kind were in the zygote, some of the resulting gametes would have none.

2. If we found that one segment was hit twice as often as the other, we would judge it to be twice as long.

3. If the physical basis of linkage were the chromosome, one might expect either complete linkage or none at all.

4. Were two chemical events required for mutation, the first small exposure would mostly bring about only one reaction per cell; in very few cells would both events occur.

5. Were there a small chance that each cell exposed to streptomycin would mutate, the distribution of numbers of mutants in different cultures should follow the Poisson formula.

6. If crossing over occurred between one and the other locus and the centromere, we would expect half of the spores produced to contain parental combinations of genes, and half to contain recombinations.

7. Only one prophage has been found in E. coli which does not segregate in crosses as would be expected if it were located on the chromosome.

8. If there were any significant variation in the sequences of the original molecules of the preparation, it would not be possible to reconstruct a single sequence from the fragments.

9. This process would be impossible in terms of energy were it not for the presence of the plasma membrane.

10. The potential difference between the two solutions will give us information about the free energy change of the oxidoreduction which would take place between the two substances if we were to mix their solutions, EV being equal to about 23 kcal.

11. If there were no other factors involved, we could predict the energy change accompanying the electron transfer from the difference in length of the upward and downward arrows, EA-IP (electron affinity-ionization potential).

12. If the spectra had been charge transfer spectra and not the spectra of the radical one would have expected marked changes in absorption when using different donors.

13. If the course of our work had to be plotted, we would plot it as a straight line.

14. A similar reaction would result if water movements were dependent on an active transport of salt.

15. Such a process would result in a marked decrease in CI^- concentration if water were retained in the lumen.

16. If the protein were to be considered as consisting of a number of identical subunits, only a fraction of the available information would be required to specify them.

17. It would probably be more interesting if I described only one of the virus types in considerable detail, for then we might begin to understand how complex, yet superbly organized, a virus particle is.

18. If this were not so, then the properties would be described by test results, as is the case at room temperature.

19. If this term were not zero it would follow that the rates of lie- forward reverse reactions were affected by some common factors.

20. The mutagen hypothesis would require that DNA be a highly specific mutagen corresponding precisely to the traits of the donor.

21. The fluid circuit mechanism requires that water be actively transported, and that solute transport depend on water movement.

22. The quantitative study of different aspects of induction and killing requires that we know the dosage relationships for the different members of the system.

23. This concept does not require that continuity between parts be maintained. It required only that the polarity of the membrane with respect to cytoplasm be constant.

24. Remarkably, one gene was always transferred first, and the others followed in order as though the genetic material were arranged in linear sequence and passed lengthwise across the cytoplasmic bridge.

25. It looks as if the problems of biology could be divided into two classes: those which current biochemistry can solve and those which it cannot.

26. It is a mistake to talk about proteins, nucleic, acids or nucleoproteins and water, as if they were two different systems. They form one single system which cannot be separated into its constituents.

Translate the text into English

Баланс энтропии при росте и развитии организмов

Общая теория роста и развития организмов на основе представлений термодинамики была выдвинута И. Пригожиным в 1947 г.

Согласно данной теории в процессе роста и развития организмов происходит уменьшение скорости продуцирования энтропии, отнесенной к единице массы объекта.

О скорости продуцирования энтропии можно судить по теплопродукции, которая сопровождает необратимые процессы в системе и отражает уровень процессов дыхания или анаэробного гликолиза и поэтому может быть оценена по характеру поглощения О₂ или образованию гликолитических продуктов.

Измерения на различных объектах скорости теплопродукции, отнесенной к единице массы, показали, что этот параметр уменьшается, начиная с первых стадий развития организмов. Изменение удельной интенсивности дыхания имеет сходную тенденцию в те же периоды эмбрионального развития.

Аналогичную картину можно получить и для целых организмов, и на изолированных органах и тканях. В процессе регенерации конечностей у амфибий, заживления ран у млекопитающих происходит также уменьшение скорости теплопродукции или уменьшение скорости продуцирования энтропии, отнесенной к единице массы.

Таким образом, согласно теории И. Пригожина, в процессе развития и роста организмов скорость продуцирования энтропии непрерывно снижается и достигает минимальных значений в конечном стационарном состоянии. Благодаря более интенсивным процессам обмена веществ отток энтропии превышает ее продукцию.

Уменьшение термогенеза в период развития может быть вызвано изменением степени сопряжения энергодающих и энергопотребляющих процессов, а также структурными перестройками макромолекул.

Можно сделать вывод о том, что в течение жизненного цикла существуют определенные периоды, когда происходит уменьшение скорости продуцирования энтропии в результате отклонения системы от стационарного состояния. Это отклонение может быть вызвано изменением условий существования или изменением внутренних параметров (температура, влажность, гормональные факторы). В процессе роста и старения организма уровни стационарных состояний изменяются: имеет место колебание содержания Са²⁺ в костях, а также величины биопотенциалов. Если эти изменения невелики, т. е. осуществляются в определенных пределах, то система или возвращается в исходное состояние, или переходит в новое. Значительные нарушения могут привести организм к гибели.

Старение, напротив, сопровождается возрастанием энтропии, которое уже не компенсируется ее оттоком в окружающую среду.

Идет накопление энтропии в системе. Как писал один стареющий физик, «меня съедает энтропия и целиком, и по частям». Скорость накопления энтропии различна у разных видов организмов. Энтропия достигает максимального значения при термодинамическом равновесии. Таким образом, живые организмы — это открытые системы, претерпевающие необратимые физиологические изменения в процессе роста и развития, происходящие через ряд состояний. При этом поступающая из окружающей среды свободная энергия затрачивается на стационарное протекание необратимых процессов, образование клеточных структур, синтез сложных молекул, что и сопровождается локальным изменением энтропии.

Жизнь — это постоянная борьба против тенденции к возрастанию энтропии. Усложнение структуры клеток в процессе эволюции (прокариоты, эукариоты) и организации живых существ — мощные антиэнтропийные факторы.

UNIT 12 The Information Content of a Nucleic Acid

One mammalian DNA molecule consists on average of 15 000 pairs of nucleotides. Assuming that the four possible types of nucleoside bases have an equal probability of occurrence, then the information content of each single nucleotide will, consequently, have a value of 2 bits. The information capacity of one DNA molecule, in this case, amounts to 30 000 bits.

The problems of this kind of calculation may be illustrated in the following example: the information content of an English text can be calculated from the frequency of the use of individual letters. In this way one can derive the information content of a word, a sentence, and, consequently, even of this textbook. It is, however, obvious that this parameter does not reveal anything about the "information value" of the book as generally understood. The same information (I) would be given by any other book with the same number of meaningless strings of English words.

This situation, however, does not invalidate Shannon's information concept. Everybody knows how important the calculation of information is today in the field of computer science. So, for example, for the author of this book it is quite important to know which sort of discs he needs to store the text and the figures of this book. But, obviously, this is just a question of its volume, of the codes used, but in no case of its "information value" in the common sense.

Does this mean that it is impossible to quantify biologically important information? Does it mean that the information concept is not applicable to biological systems at all? In fact, there is no reason for skepticism. Consequently, a distinction has to be made between a syntactic measure of information, and a semantic measure.

The syntactic information content of a DNA molecule, as calculated above, provides some information on the maximum storage capacity of the genome. The amount of information actually stored is even lower, if the redundancy in the storage of genetic information which is required for the protection of the information is taken into account. Estimates of information capacity in the genome vary between 3 • 10² bit and 10¹² bit.

The semantic information, in contrast to the syntactic information, really should contain some kind of validation of the content. Despite many attempts, quantification of semantic information has not yet been achieved. In spite of the problems of giving an exact and meaningful quantification of information, it is doubtless a quality of matter and has a place in information theory and thermodynamics.

Define the following words using a dictionary

A parameter, skepticism, redundancy, capacity, to reveal, to invalidate

Complete the sentences

1. It is, however, obvious that…

2. The amount of information actually stored…

3. Despite many attempts,…

4. Assuming that the four possible types of nucleoside bases have an equal probability of occurrence,…

5. Obviously, this is just a question of its volume,

6. Consequently, a distinction has to be made…

7. In this way one can derive…