Reaction mechanisms[ edit ] Nucleophilic substitution can occur in two different ways. SN2 involves a backside attack.
The talk, as I remember it, plus some stuff I had to cut for time is below. The jury is still out on the theory, and there are plenty of reasons to doubt it.
But if it successfully predicts what happens over the next ten years it will have in good part proved its power. Is this the way innovation progresses, a never-ending stream of new things? If you look at the history of technological innovation over the course of decades or centuries, not just years, it looks completely different.
It looks like innovation comes in waves: This was followed by the spread of the railways and steam power, the age of steel, and the Age of Oil, Autos, and Mass Production from the beginning of the 20th century to the s.
The wave that we are currently in, the Information and Communications Technology Revolution, started around These cycles have eerie similarities. What dynamic could cause it? From the Industrial Revolutions to the Information Revolution.
Her answers lie not just in technological change, but in the social, institutional, and financial aspects of our society itself.
When this system allows a fundamental and basic innovation, the system can cause a technological revolution. For example, here is a group of some of the technologies involved in the start of the Railroad revolution. The railroad was invented to solve a problem: But the railroad addressed a broader and more basic need: It did more than move coal from mine to ship, it moved goods from city to city, it moved mail from city to city, it moved people from city to city, and those people started living away from their hometowns en masse for the first time.
Another constellation of technologies started the ICT revolution: Some of these together allowed the creation of the microprocessor. Originally built to power portable calculators, it ended up addressing another broad and basic need and started a new technological revolution.
When some of the technologies in a linked system progress faster than others, the laggards become the limiting factor in the system. The system can not progress until the reverse salient is cured, so economic resources are directed to its improvement.
If you see a reverse salient, you have found a problem whose solution is far more valuable than it may first seem. Currently, the most obvious reverse salient is battery technology.
The techno-economic paradigm shows a way of using the new technology to make businesses more efficient and profitable, and so more competitive than existing businesses.
But existing businesses have a techno-economic paradigm of their own, the one associated with the previous technological revolution, and they have a lot invested in the old way of doing business. So adoption of the new technologies is slow at the beginning and incumbents resist it.
Money starts to flow into the sector. But a few hit big, and other financiers notice. In the current ICT revolution, think about the investments in Apple Computer and Intel by the then new venture capital industry 3. Seeing the money to be made, money starts to pile into the new technologies.
As the scale of the new opportunity becomes more evident with each successful investment, investment in the sector grows exponentially.
For example, the small venture capital industry of the s lead to the much larger VC industry of the s and then to the dot-com frenzy of the s.Try writing a mechanism for this reaction using the two steps outlined above.
Include all Note: we want to choose the most likely attack, which creates the most resonance- electrophilic aromatic substitution mechanism.
Try this problem (14D Thinkbook, PP#12d) Solution.
C) The reaction in cells must be catalyzed by enzymes, but the reaction in a test tube does not need enzymes. D) Reactant and product concentrations in the test tube are different from those in the cell. 17) Draw all likely alkene products in the following reaction and circle the product you expect 17) to predominate.
18) Draw all likely alkene products in the following . The enzyme is consumed by the reaction 1. Which of the following would interfere most with the ability of an enzyme to catalyze a reaction? the following would be most effective as a feedback mechanism?
1. Reduced concentration of product One lactase enzyme can catalyze many reactions Sample Answer Key Biology.
6 ) Which of the presented mechanisms would be the most energetically favorable and thus the most likely mechanism to actually occur for the following free radical chain reaction. This is an easy way of producing an ester from an alcohol because it happens at room temperature, and is irreversible.
Making an ester from an alcohol and a carboxylic acid (the usual alternative method) needs heat, a catalyst and is reversible - so that it is difficult to get a % conversion.