Text 13. Dna Stretching Mystery is Solved

Active Vocabulary:

to unravel	розплутувати	bead	кулька, бульбашка
mystery	таємниця	to pull apart	розривати
to stretch	натягуватися	tweezing	розщеплення
breaking point	межа міцності	zipper	змійка
researcher	дослідник	transition	переміщування
to carry out	виконувати	tension	напруга
to attach	приєднувати	strand	ланцюжок молекул

Researchers in Europe have unravelled a mystery that has been puzzling scientists for years: what happens to a molecule of DNA when it is stretched to its breaking point.

Now Erwin Peterman and his colleagues appear to have answered the question. The researchers carried out a DNA-stretching experiment by attaching one end of each strand of a length of double-stranded DNA to a polystyrene bead. The beads could be pulled apart with a controlled and measurable force by lasers – a process called optical tweezing.

“Pulling the DNA from both ends is a bit like pulling on a jacket that has a double-ended zipper,” says Peterman. “What we found was that at the transition force the zipper starts to come apart at either end, but remains zipped in the middle. In other words, the DNA comes apart at either end, and under tension this single-stranded DNA is 70 percent longer than double-stranded DNA.”

It is a great work. It tells us about the way the structure of a single molecule is changing under tension, something we have not been able to see before. It looks as though they have solved the question, but as always it is very complicated. So this might not be the end of the story.

Speech Patterns

He	appeared	to have forgotten my address.	Виявилось, що він забув мою адресу.
	seems		Здається, він забув мою адресу.

І. Decide which of these statements are true and which are false.

1. The researchers have been stretching strands of DNA for ages. 2. The scientists have divided strands of DNA into two different parts. 3. A single-stranded DNA is as long as a double-stranded one. 4. The structure of a single molecule can be changed under pressure.

ІІ. Answer the following questions.

1. Who carried out a DNA-stretching experiment? 2. What was the DNA-stretching experiment? 3. What happened to a molecule of DNA when it was stretched to its breaking point? 4. Is this experiment useful? Why?

Text 14. Status of Genetically Modified Products

Active Vocabulary:

advance	рух уперед	raw material	сировина
tissue	тканина	objection	заперечення
to emerge	з’являтися	consumer	споживач
crop breeding	вирощування зерна	detrimental	нищівний
benefit	прибуток, перевага	affordable	доступний
enhanced crop yield	підвищений врожай зерна	current	сучасний
nutritious	поживний	to assist	сприяти, допомагати
efficiency	ефективність	to reduce	зменшувати

The development of modern biotechnology is really a ground-breaking advance because of its enormous power to transform living things. New techniques such as tissue culture, cell culture and embryo transfer, as well as various techniques of molecular manipulation, have emerged. Transgenic technologies such as genetically modified organisms (GMOs) are now being widely used in crop breeding and commercial production.

There are a number of actual or potential benefits from GM crops. These include:

• Enhanced crop yield and productivity;

• More nutritious and higher quality products;

• Less need for pesticides and herbicides;

• Greater efficiency in resource management;

• Role as a bioreactor to produce raw materials for pharmaceuticals and other industries.

For critics, there are four main objections:

• Consumers do not have enough information about GMOs.

• There may be potential detrimental effects from eating GM foods, while there have not yet been objective studies to identify such effects, if they exist.

• There may be unexpected environmental problems.

• Using of GM crops may go against certain religious beliefs and traditions.

So, rapid introduction of GM products into the market is really amazing. Many of the key technologies are in the hands of the private sector, and dominated by a few companies. The use of transgenic modification could have benefits for developing countries only, due to an affordable cost.

So, there are some more problems of using these products.

• Many developing countries can not afford the cost of biotechnology.

• The crop genetic improvements that are currently available are not suitable for developing countries.

• The question is who will assist developing countries, and what type of assistance is appropriate.

Population growth and food distribution will most likely remain the two most critical problems which mankind must face for many years to come. Biotechnology offers the potential to reduce uncertainty in the world’s future food supply, in the face of a growing population and the limited carrying capacity of the Earth.

Speech Patterns

The years to come	Наступні роки
The words to remember	Слова, що треба запам’ятати
The things to do	Все, що треба зробити

You have to hurry to catch the train.	Ви повинні поквапитись, щоб встигнути на потяг.
To drive a car you must get a license.	Для того, щоб водити автомобіль, потрібно отримати права.

І. Decide which of these statements are true and which are false.

1. Transgenic technologies have been known since ancient times. 2. Genetically modified food is very useful for our body. 3. GMOs may cause plenty of environmental problems. 4. A developing country should have a fortune of money to afford the cost of biotechnology.

ІІ. Answer the following questions.

1. What new techniques in modern biotechnology do you know? 2. What are pros and cons of GM crops? 3. What is the situation with GM products on the market? 4. How can you solve the problem of food supply for all the mankind?

Text 15. The Big Future of Nanotechnology

Active Vocabulary:

to deal	діяти	tool	інструмент
realm	сфера, галузь	fuel cell	паливний елеметн
invisible	невидимий, непомітний	cell	1) клітина; 2) елемент; 3) секція; відсік; 4) сота
dwarf	гном	cancers	рак
by account	за оцінкою	without controversy	безсумнівно, безперечно
stain-proof	брудовідштовхувальний	nanoparticle	наночастинка
fabric	тканина	device	прилад
scratch-resistant	стійкий до подразнень	to punch	пробивати отвір

Nanotechnology deals in the realm of the nearly invisible. The word comes from the Greek nanos, meaning “dwarf”. But by most accounts, the technology’s potential is anything but small. Scientists and engineers can now physically work with materials at the atomic level to create stain-proof fabrics, scratch-resistant paints and longer-lasting tennis balls. And researchers say new medical diagnostic tools and smaller, more efficient fuel cells and batteries based on nanoscience are on the way.

From computer chips invisible to the naked eye to microscopic machines that seek out and destroy cancers inside the human body, a lot of scientists argue that the potential of nanotechnology could be endless, but not without controversy.

“If we can get a nanoparticle into a cell, that might prove to be a new and useful drug delivery device,” says Ms. Kulinowski, Executive Director of the Center for Biological and Environmental Nanotechnology at Rice University. “On the other hand, it might prove to be a toxin to the cell either by punching a hole in the cell membrane or otherwise disrupting the cell’s function”.

Whether the benefits of nanotechnology outweigh the risks will determine the future of what many researchers hope will be the world’s next industrial revolution.

Speech Patterns

He	is anything but	lazy.	Він далеко не ледащий.
It		pleasant.	Це зовсім не приємно.

On the one hand	З одного боку
On the other hand	З іншого боку

І. Decide which of these statements are true and which are false.

1. Nanoparticles are very big. 2. Nanotechnology has a great potential. 3. There is no need to use nanotechnology in medicine. 4. Nanotechnology is a step to the industrial revolution.

ІІ. Answer the following questions.

1. What does the word nanos mean? 2. At what spheres of industry can you use nanotechnology? 3. Why is nanotechnology useful? 4. How do nanoparticles influence the cells?

Text 16. The Greenhouse Effect

Active Vocabulary:

greenhouse	теплиця	wave-length	довжина хвилі
to trap	поглинати, вбирати	to impact	мати вплив
to radiate	випромінювати	surface	поверхня
to spread	поширювати	to blanket	заглушати
global warming	глобальне потепління	to escape	виходити
transparent	прозорий, відкритий	space	космос, простір
to income	надходити	level	рівень
to convert	перетворювати	average	середній

The light from the sun comes in, and the greenhouse gases trap some of the heat radiated from the Earth. It’s an energy balance. The more heat that comes in or the more heat that is trapped, the higher the energy balance is. The bigger the ice fields, the lower the Earth’s energy balance.

A fundamental error is being spread that, because a global warming gas is transparent to a large amount of the incoming radiation from the sun, it cannot have much effect in terms of warming the planet. This is an error that ignores a real-world fact that incoming radiation is converted to longer wave-lengths as it impacts the atmosphere and the planetary surface. It is these longer wave-lengths that are then blanketed from escaping back into space. If it were not for this wave-length conversion (mechanism), the greenhouse gases (GHGs) would not be causing the rise in the level of the Earth’s energy balance.

The energy balance for the Earth is about 33° Centigrade higher than it would otherwise be if there was no greenhouse effect. The average temperature on Earth is about 16° Centigrade. Thus, it would be more like -17° Centigrade, if there were no greenhouse gases in the atmosphere and, therefore, no greenhouse effect. The best estimate is for climate sensitivity to be 3°С. Values substantially higher than 4.5° C cannot be excluded.

Speech Patterns

If it were not for X ... we would ...	Якби не Х, ми б ...
If it were not for hope, the heart would break.	Якби не надія, серце б розірвалось. (Надія вмирає останньою.)

І. Decide which of these statements are true and which are false.

1. Energy balance depends on heat level. 2. GHGs can not cause the rise in the level of the Earth’s energy balance. 3. The average temperature on Earth is about 18° Celsius. 4. The best temperature for climate is 3° F.

ІІ. Answer the following questions.

1. What is an energy balance? 2. What error information is spread all over the world? 3. What is the difference between a greenhouse effect and a global warming? 4. Is there any danger in the greenhouse effect?