Области применения биофизики.

Биологические объекты, как правило, очень

сложны и на протекающие в них процессы влияют многие факторы, которые часто зависят друг от друга. Физика позволяет создать упрощенные мо- дели объекта, которые описываются законами термодинамики, электродинамики и т.д.

В физике имеется множество методов, кото- рые в своей первоначальной форме не могут быть использованы для исследований биологических объектов. Поэтому ещё одной задачей биофизики является приспособление этих методов и методик для решения задач биологии. Сегодня для получе- ния информации в биологических системах при- меняют различные оптические методы, рентгено- структурный анализ, ЯМР - и ЭПР- спектроскопию, различные электрометрические методы, методы хемилюминесценции, лазерную спектроскопию, метод меченых атомов и др. Это используется, в частности, для медицинской диаг- ностики и терапии.

 

19. Write an essay on the topic “Prospects of biophysics”.

20. With the group of your colleagues make a presentation about the following selected topics in biophysics:

· Biophysical mechanisms

· Biophysical techniques

· Molecular structure and behavior

sis?

Unit 10 Physicochemical methods of analysis

What are the physicochemical methods of analy-

What kinds of physicochemical methods do you

they constitute to one of the parts of analytical chemis- try. The essence of the physical and chemical methods of analysis is to study relations between structure and properties of systems. For the analysis of substances chemical reactions are widely used. They are accom- panied by changes in the physical properties of the analyzed system, for example, the color intensity of

know?

What is the basis of physicochemical methods of analysis?

1. Read this text and translate it.

Physicochemi- cal Methods of

Analysis: What Are These?

It seems that this term can be met only in Russian. In the English- language literature, they usually speak and write about instrumental methods of analysis. The name instru- mental is evidently not ideal; analytical balances or titrimeters used in classical chemical methods also be- long to instruments.

Physicochemical methods of analysis have wider application. Without them it is hard to control and manage production processes and research. It should be noted that physicochemical methods of analysis solve the problems of chemical control and analysis;

fluorescence, etc. So physicochemical methods of analysis is a field of analytical chemistry that investi- gates analyses using scientific instruments. There are several types of instrumental analyses.

Spectroscopy measures the interaction of the molecules with electromagnetic radiation. Spectros- copy consists of many different applications such as atomic absorption spectroscopy, atomic emission spectroscopy, ultraviolet-visible spectroscopy, x-ray fluorescence spectroscopy, infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance spectroscopy, photoemission spectroscopy and so on.

Mass spectrometry measures mass-to-charge ra- tio of molecules using electric and magnetic fields. There are several ionization methods: electron ioniza- tion, chemical ionization, electrospray, fast atom bombardment, matrix-assisted laser desorp- tion/ionization, and others.

Crystallography is a technique that characterizes the chemical structure of materials at the atomic level by analyzing the diffraction patterns of electromag- netic radiation or particles that have been deflected by atoms in the material. X-rays are most commonly used. From the raw data the relative placement of at-

oms in space may be determined.

Electroanalytical methods measure the electric potential in volts and/or the electric current in amps in an electrochemical cell containing the analyte. These methods can be categorized according to which as- pects of the cell are controlled and which are meas- ured. The three main categories are potentiometry (the difference in electrode potentials is measured), cou- lometry (the cell's current is measured over time), and voltammetry (the cell's current is measured while ac- tively altering the cell's potential).

Calorimetry and thermogravimetric analysis

measure the interaction of a material and heat.

Separation processes are used to decrease the complexity of material mixtures. Chromatography and electrophoresis are representative of this field.

Microscopy. The visualization of single mole- cules, single biological cells, biological tissues and nanomaterials is very important and attractive ap-

chromatography-infrared spectroscopy, liquid chroma- tography-mass spectrometry and so on.

A general method for analysis of concentration involves the creation of a calibration curve. This al- lows for determination of the amount of a chemical in a material by comparing the results of unknown sam- ple to those of a series known standards. If the concen- tration of element or compound in a sample is too high for the detection range of the technique, it can simply be diluted in a pure solvent. If the amount in the sam- ple is below an instrument's range of measurement, the method of addition can be used. In this method a known quantity of the element or compound under study is added, and the difference between the concen- tration added, and the concentration observed is the amount actually in the sample.

 

Vocabulary

proach in analytical science.

Also, hybridization with other traditional analyti- cal tools is revolutionizing analytical science. Micros- copy can be categorized into three different fields: op- tical microscopy, electron microscopy, and scanning probe microscopy. Recently, this field is rapidly pro- gressing because of the rapid development of the computer and camera industries. Combinations of the above techniques produce a "hybrid" or "hyphenated" technique. Several examples are in popular use today and new hybrid techniques are under development, for example, gas chromatography-mass spectrometry, gas

accompanied analytical chemistry

atomic absorption spec- troscopy

atomic emission spec- troscopy

biological tissues calibration curve calorimetry chemical structure color intensity coulometry

crystallography decrease (v) electric current electric potential electroanalytical method

electromagnetic radia- tion

electrospray

fast atom bombardment fluorescence hybridization

ionization methods infrared spectroscopy instrumental analyse investigate (v)

mass spectrometry mass-to-charge ratio microscopy

resonance spectroscopy photoemission spec- troscopy

property

potentiometry production processes pure solvent separation processes single molecule solve (v)

ultraviolet-visible spec- troscopy

voltammetry

x-rayfluorescence

зить уровень абсорбации.

 

4. Fill in the gaps in this sentences:

1) Physicochemical methods of have wider application.

2) Spectroscopy measures the interaction of the molecules with.

3) From the raw data the relative placement of

in space may be determined.

4) Separation processes are used to decrease the complexity of.

5) The visualization of single molecules, single

3. Translate the sentences with the words from vocabulary after the text.

1) Флюоресценция - свечение некоторых тел под влиянием освещения, по прекращении кото- рого свечение не наблюдается.

2) Чистый растворитель не обладает запа- хом и не токсичен.

3) Достаточно знать химический со- став вещества и его плотность, что- бы предсказать и все его прочие свойства.

4) Ученым необходимо измерить оптиче- ские линий одиночных молекул.

5) Спектроскопия обнаруживает и определя- ет вещества при помощи измерения их характе- ристических спектров.

6) После изучения теории ученые принялись

исследовать новый материал.

7) В этом эксперименте необходимо пони-

biological cells, biological tissues and nanomaterials is very important and attractive approach in.

6) Microscopy can be categorized into three dif- ferent fields:,, and scanning probe microscopy.

 

4. Write out the sentences expressing the main ideas of each logical part of the text.

5. Write a summary of the text in your own words making use of plan and the sentences you’ve written out.

6. Choose the type of instrumental analysis and make a detailed presentation about it.

7. Past Perfect and Past Perfect Progressive. Choose the correct sentence from each pair.

1) I knew the facts of the case because I had

read / had been reading the report.

2) My eyes ached because I had read / had been reading for three hours.

3) The children were filthy. They had played / had been playing in the garden, and they were covered in mud.

4) I was very nervous at the beginning of the match. I had never played/ had never been playing her before, and I didn't know how good she was.

5) Donald excelled himself as a cook. He had cooked / had been cooking a wonderful Spanish dish.

6) Donald was very cross. He had worked/ had been working in the kitchen all morning, and none had offered to help.

 

8. Define if the verb tenses in these sentences are correct.

1) He had been sitting here for 40 minutes when the telephone rang.

2) I had tried to get him on the phone all day.

3) When Sarah arrived at the party, Paul had been already going home.

4) When we got back the babysitter had gone home.

5) Tom had done his homework for an hour when his friend came to see him.

6) They had hoped to get the summit but Travers fell ill at base camp.

7) When we got home last night, we found that somebody had been breaking into the flat.

8) At eight in the morning we had been driving for six hours.

 

9. Read this text and translate it.