Discuss the roles that the protein components play in the classes of metalloproteins.
Discuss the roles that the protein components play in the following classes of metalloproteins: i. electron transfer proteins: Electron transfer reactions involves a switch in the redox states of a metal ion whether it involve Cu(I)/Cu(II), as is the case in blue copper proteins for example, or Fe(II)/Fe(III) as is the case in cytochromes or Fe-S cluster proteins. In any case the protein component of the metalloproteins plays significant roles, some of which are: . protection of the redox site from solvent or other reactive species if necessary 2. optimizing the local electrostatic environment 3. optimizing the spatial arrangement do that the electron transfer distances are minimised 4. fine tuning the environment around the metal centre to adjust the redox potential 5. selection of the metal centre 6. selection of reaction partners If metal ions in electron transfer metalloproteins are the site of electron transfer, the protein component in such proteins is important for establishing the metal binding pocket, and providing most if not all of its coordinating ligands. This is done in such a way as to optimize electron transfer, and can be illustrated for example in blue copper proteins. Indeed, the protein ligands coordinating the copper hold the latter in a much distorted arrangement keeping it an entatic state. This irregular high energy arrangement of the metal
Fermentation is the process of yeast, which converts sugars (glucose) into carbon dioxide and alcohol.
Introduction Fermentation is the process of yeast, which converts sugars (glucose) into carbon dioxide and alcohol. The general formula for this is: Glucose Ethanol + Carbon Dioxide C6H12O6 2C2H5O + 2CO2 Fermentation is a type of anaerobic respiration. Yeast contains single- celled organisms that can respire aerobically. After yeast is combined with sugar, it begins to respire. This reaction produces carbon dioxide, water and energy. So the equation so far is: Glucose + Oxygen Carbon Dioxide + Water + Energy C6H12O6 + 6O2 6CO2 + 6H2O + 2900kj When all the oxygen is used up, the yeast keeps on respiring. The glucose is used up. Due to a lack of oxygen, the products produced are carbon dioxide and ethanol. Therefore the overall process for fermentation is: Glucose Carbon Dioxide + Ethanol + Energy C6H12O6 2CO2 + 2C2H5OH + 84kj Mrs Leaf's problems with her bread dough could have many solutions I believe these could be greatly influenced by temperature. I will investigate what causes bread dough to rise a part from sugar and yeast content. From my preliminary investigation I have discovered that if the yeast to flour ratio is higher then the dough will raise more with this thinner dough. In my preliminary experiment I did not alter the temperatures I left the solution in a water bath at 40 degrees for ten minutes however to achieve a wider range of results I will alter
The discovery of the electron.
The Discovery of the Electron By Joseph John Thomson Soua Lee Prof. Giunta CHM 113 November 24, 2002 Outline I. How the electron was discovered? A) Discovered in 1897 by Joseph John Thomson B) Discovered in the form of cathode rays II. Who was Joseph John Thomson? A) Born on December 18, 1856. B) Lived in Manchester, England. C) Attended Owens College in Manchester. D) Continue crafting mathematical models at Trinity College. III. Experiment in the Cavendish Laboratory A) Worked under the influence of Lord Rayleigh. B) Published the determinations of the ratio of the electrostatic and electromagnetic units. C) Became the Chair of Physics at Cambridge after Rayleigh resigned. IV. J.J. Thomson's experiments: A) Measured the speed of cathode rays, which led to the discovery of electrons. B) Used a vacuum tube to do his experiment on cathode rays. C) Used other tubes of various designs for his experiment, where one he used to most effect. V. Thomson's three hypothesis: A) Cathode rays are charged particles. B) These corpuscles are constituents of the atom. C) These corpuscles are the only constituents of the atom. VI. Conclusion A) His various experiment on cathode rays led him to the discovery of the electron. B) He proved the existence of this entirely new particle to be more than 1000 times lighter than any known atom. C) "Corpuscles" which was
I am trying to find out what insulator is best at keeping the most heat in. I will try out lots of different insulators such as cloth, newspaper, a lid, none and bubble wrap to see what will happen.
Science Coursework Investigating Cooling Hypothesis What do I already know Energy is transferred from atom to atom along the bar. At the hot end, the atoms are vibrating a lot. As they bump into each other, the energy is passed along the bar. Heat Transfer For heat to flow from A to B, A must be at a higher temperature than B. Heat energy causes gas and liquid molecules to move around faster, and causes particles in solids to vibrate more rapidly. When particles move faster it shows up as a rise in temperature. This extra kinetic energy in the particles tends to get dissipated to the surroundings. In other words the heat energy tends to flow away from a hotter object to its cooler surroundings. If there's a difference in temperature between two places then heat will flow between them. Conduction Is the transfer of energy (heat) between materials in contact it happens mostly in solids, but also a little in liquids. As part of substances is heated the particles inside it vibrate. These vibrations are passed from particle to particle. Without the material or the substance moving. Convection happens in liquids and gases it is the transfer of energy (heat) by the movement of a liquid or a gas due to differences in density. Water is heated and Water cools, Becomes less dense
Black body radiation - Radiation is emitted from all objects above absolute zero; the rate of energy per unit area per unit time is proportional to T4.
Black body radiation Introduction Radiation is emitted from all objects above absolute zero; the rate of energy per unit area per unit time is proportional to T4. P=?A?T4 P?T4 P= power Watts ?= emissivity unit less constant related to the colour and reflectivity ?=Stephan's constant Wm-2k-4 T=temperature Kelvin The peak wavelength of the radiation emitted can be calculated from Wein's displacement law which states ?mT=2.898x10-3 where ?m is the peak wavelength. I will be investigating Wein's displacement law and the emissivity of a number of different surfaces. I will also be investigating how power affects temperature using Stefan's power law. Experiment 1 I will be using a computer program to simulate various temperatures and recording the peak wavelength (?m) that corresponds to a number of temperatures. I will then be plotting a graph of ?m against 1/T, the gradient of which should be 2.898x10-3 mK. I will compare my results with Wein's displacement law (see example below). Experiment 2 I will fill a cube with different emissivities on each side with boiling water and record the temperature it boils at as the pressure in the room will probably not be 1 atmosphere so the water will not boil at exactly 1000C. I will record a reading of mV from a thermopile. As one of the sides is black, I will assume it is an ideal blackbody with an emissivity of 1. By
A neutrino is a subatomic particle that is very similar to an electron, but has no electrical charge and a very small mass, which might even be zero.
A neutrino is a subatomic particle that is very similar to an electron, but has no electrical charge and a very small mass, which might even be zero. Neutrinos are one of the most abundant particles in the universe. Because they have very little interaction with matter, however, they are incredibly difficult to detect. Nuclear forces treat electrons and neutrinos identically; neither participate in the strong nuclear force, but both participate equally in the weak nuclear force. Particles with this property are termed leptons. In addition to the electron (and it's anti-particle, the positron), the charged leptons include the muon (with a mass 200 times greater than that of the electron), the tau (with mass 3,500 times greater than that of the electron) and their anti-particles. Both the muon and the tau, like the electron, have accompanying neutrinos, which are called the muon-neutrino and tau-neutrino. The three neutrino types appear to be distinct: For instance, when muon-neutrinos interact with a target, they will always produce muons, and never taus or electrons. In particle interactions, although electrons and electron-neutrinos can be created and destroyed, the sum of the number of electrons and electron-neutrinos is conserved. This fact leads to dividing the leptons into three families, each with a charged lepton and its accompanying neutrino. To detect neutrinos,
In order to understand the everyday use of radar and the physics of flight, we took an industrial visit to Shoreham airport a small airport, which is fairly local.
In order to understand the everyday use of radar and the physics of flight, we took an industrial visit to Shoreham airport a small airport, which is fairly local. The airport has a very long history going back all the way to 1911 not long after the first manned flight in a "heavier than air" flying machine by the Wright brothers in 1903. History In 1930 the municipal authorities of Brighton, Hove and Worthing formed a joint committee to establish Shoreham as the municipal airport for three towns. Construction on the Terminal Building began in November 1934. During World War II, Shoreham Airport was used as a training facility for pilots, and also housed a training dome for Anti air and Bomber gunners. The dome is now a listed building and is one of the last surviving gunner training domes in the country. After the War, the introduction of jet aircraft brought about the end of Shoreham as a passenger flight airfield, however it has maintained itself as an airport for many private light aircraft and helicopters, as well as the Sussex police/hospital helicopter. Flight 'Heavier than air' flying machines must have someway of taking off from the ground; they must be self-propelled, and must have some way to create lift, (aeroplanes have wings, and helicopters have rotor blades). There are two main ways for wings to create lift; The Longer Path, (Bernoulli or equal transit
To see how one variable affects the speed at which alcohol evaporates.
Evaporation Of Alcohol Aim: To see how one variable affects the speed at which alcohol evaporates. Background Information: I already know that forces of attraction between particles in a liquid are weaker than those in a solid. Liquids cannot be compressed because there is no space between the particles. Particles in a gas move quickly in all directions. Gases are easily compressed because there is more space between the particles. When a substance is heated it has more energy to escape the forces of attraction between the particles. I know that alcohol is very volatile compared to water. When a liquid is heated it will evaporate and become a gas. Many things affect the rate of evaporation: Room temperature Liquid temperature Surface temperature Surrounding wind speed Surface area of alcohol Concentration of alcohol Barrier of container alcohol is in. Prediction: I think that the 70 C experiment will make the most alcohol evaporate and the 30 C experiment will evaporate the least. I think this because heat speeds up the random movement of the molecules and so they will evaporate faster the hotter the water is underneath it. Method: See Plan. Diagram: Results: Test 1 Test 2 Temperature Of Water ( C) Volume Of Alcohol Left (Ml) Volume Of Alcohol Left (Ml) 70 9 9 60 9.3 9.2 50 9.4 9.3 40 9.5 9.4 30 9.7 9.7 Conclusion: I found
Types of particle
Neutron A Neutron is an uncharged particle, one of the fundamental particles of which matter is composed. The mass of a neutron is 1.0086654 atomic mass units (amu). The existence of the neutron was predicted in 1920 by the British physicist Ernest Rutherford and by Australian and American scientists, but experimental verification of its existence was exceedingly difficult because the net charge on the neutron is zero. Discovery The neutron was first identified in 1932 by the British physicist Sir James Chadwick. The Joliot-Curies had produced what Chadwick recognized as neutrons by the interaction of alpha particles with beryllium nuclei. When this newly discovered radiation was passed through paraffin wax, collisions between the neutrons and the hydrogen atoms in the wax produced readily detectable protons. Behavior The neutron is a constituent particle of all nuclei of mass number greater than 1. Free neutrons-those outside of atomic nuclei-are produced in nuclear reactions. They can be ejected from atomic nuclei at various speeds or energies and are readily slowed down to very low energy by a series of collisions with light nuclei, such as those of hydrogen, deuterium, or carbon. When expelled from the nucleus, the neutron is unstable and decays to form a proton, an electron, and a neutrino. Like the proton and the electron, the neutron possesses angular momentum,
How do neon lights work?
How do neon lights work? By definition, the atoms of inert gases such as helium, neon or argon never (well, almost never) form stable molecules by chemically bonding with other atoms. But it is pretty easy to build a gas discharge tube-such as a neon light-which reveals that inertness is a relative matter. One need apply only a modest electric voltage to electrodes at the ends of a glass tube containing the inert gas and the light begins to glow. It's much easier to explain why neon isn't inert in a discharge tube than it is to explain why it is inert to chemical reactions. The voltage across a discharge tube will accelerate a free electron up to some maximum kinetic energy. The voltage must be large enough so that this energy is more than that required to "ionize" the atom. An ionized atom has had an electron plucked out of an orbital to make it a "free" particle, and the atom it leaves behind has become a positively charged ion. The resulting plasma of charged ions and electrons carries the electric current between the tube's electrodes. The photo (above) shows a gas discharge sign. This sign incorporates a neon discharge tube (the orange word "Physics") and mercury discharge tubes (the blue word "Experience" and the outer frame). The sculpture at the bottom of the sign represents the electric and magnetic fields of light. The white and yellow sine waves in the sculpture