What is the main enzyme component of Sanger sequencing?
A.Helicase
B.Polymerase
C.Nuclease
D.Gyrase
A.Helicase
B.Polymerase
C.Nuclease
D.Gyrase
Sugar Power for Cell Phones
Using enzymes commonly found in living cells, a new type of fuel cell produces small amounts of electricity from sugar. If the technology is able to succeed in mass production, you may some day share your sweet drinks with your cell phone.
In fuel cells, chemical reactions generate electrical currents. The process usually relies on precious metals, such as platinum. In living cells, enzymes perform. a similar job, breaking down sugars to obtain electrons and produce energy.
When researchers previously used enzymes in fuel cells, they had trouble keeping them active,says Shelley D. Minteer of St LouisUniversity. Whereas biological cells continually produce fresh enzymes, there&39;s no mechanism in fuel cells to replace enzymes as they quickly degrade.
Minteer and Tamara Klotzbach, also of St LouisUniversity, have now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket. "We tailor these pockets to provide the ideal microenvironment for the enzyme," Minteer says. The polymers keep the enzyme active for months instead of days.
In the new fuel cell, tiny polymer bags of enzyme are embedded in a membrane that coats one of the electrodes. When glucose from a sugary liquid gets into a pocket, the enzyme oxidizes it, releasing electrons and protons. The electrons cross the membrane and enter a wire through which they travel to the other electrode, where they react with oxygen in the atmosphere to produce water. The flow of electrons through the wire constitutes an electrical current that can generate power.
So far, the new fuel cells don&39;t produce much power, but the fact that they work at all is exciting, says Paul Kenis, a chemical engineer at the University of Illinois at Urhana-Champaign.
"Just getting it to work," Kenis says, "is a major accomplishment."
Sugar-eating fuel cells could be an efficient way to make electricity. Sugar is easy to find. And the new fuel cells that run on it are biodegradable, so the technology wouldn&39;t hurt the environment.
The scientists are now trying to use different enzymes that will get more power from sugar. They predict that popular products may be using the new technology in as little as 3 years.$amp;According to the first paragraph, when can we share our sweet drinks with our cell phones? 查看材料;$br>
A.When enzymes can be commonly found in living cells
B.When the technology of producing a new type of fuel cell appears
C.When the technology of a new type of fuel cell is suitable for mass production
D.When the technology of mass producing cell phones appears
A、benefit
B、 benefitting
C、 benefits
(二)66Scientists and experts have proved the uniqueness of finger-prints and discovered that no exactly similar pattern is passed on from parents to children, though nobody knows why this is the case. The ridge (隆起) structure on a person's fingers does not change with growth and is not affected by surface injuries. Burns, cuts and other damage to the outer part of the skin will be replaced in time by new one, which bears a reproduction of the original pattern.67Some criminals make use of this fact to remove their own finger-prints but this is a dangerous and rare step to take. Finger-prints can be made very easily with printer's ink. They can by be recorded easily.68Because of the simplicity and economy of this system, finger-prints have often been used as a method of solving criminal case. A suspected man may deny a charge but this may be in vain.69. When a suspect leaves finger-prints behind at the scene of a crime, they are difficult to detect with the naked eye.70Some of the marks found are incomplete but identification is possible if a print of a quarter of an inch square can be obtained.
F. His finger-prints can prove who he is even if his appearance has been changed by age or accident. G. Every human being has a unique arrangement of the skin on his fingers and this arrangement is unchangeable. |
A、Exogenous
B、DNA
C、Deoxynucleotides
D、Dideoxynucleotides
A、DNA ligase quickly re-seals target sequences when they are cut.
B、Proteins attach to the target sequences, preventing restriction nucleases from binding.
C、The bacterium chemically modifies its own DNA sequences, thereby preventing recognition by the nucleases.
D、Bacterium has membrane organelle to contain and protect the DNA.
A、specifically label the DNA sequence of interest within a given band.
B、visualize the separated DNA bands in the gel.
C、identify the desired nucleotide sequence by complementary base pairing.
D、denature the DNA sequence of interest.
为了保护您的账号安全,请在“简答题”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!