| 单词 | hydrogen ion |
| 例句 | There was no evidence that hydrogen ions had charged around Edlefsen’s “rather sketchy” apparatus at all, much less at any appreciable fraction of 1 million electron volts. Big Science 2015-07-07T00:00:00Z That protein, called OTOP1, sits within cell membranes and forms a channel for hydrogen ions moving into the cell. And then there were 6 -- kinds of taste, that is 2023-10-05T04:00:00Z A solution with a high number of hydrogen ions is acidic and has a low pH value. Concepts of Biology 2013-04-25T00:00:00Z In the reaction, a molecule of hydrogen gas collides with one deuterium ion to produce a hydrogen ion and a heavy, deuterium-containing hydrogen molecule. Bizarre Quantum Tunneling Observation Throws Out All the Rules 2023-04-04T04:00:00Z But getting hydrogen ions to fuse into helium and release energy requires temperatures of more than 100 million degrees Celsius—conditions that are hard to achieve and sustain. With historic explosion, a long sought fusion breakthrough 2022-12-13T05:00:00Z The carbon dioxide was then dissolved in water, reacting to produce hydrogen carbonate, a weak acid that subsequently ionized to yield bicarbonate and hydrogen ions: Chemistry 2019-02-14T00:00:00Z Because ammonium chloride can affect the concentration of acid -- that is, hydrogen ions -- within a cell, the team wondered if it could somehow trigger OTOP1. And then there were 6 -- kinds of taste, that is 2023-10-05T04:00:00Z Approximately how much of an increase in hydrogen ion concentration is there between tomato juice and lemon juice? Concepts of Biology 2013-04-25T00:00:00Z After waiting for about 15 minutes, the scientists measured how many hydrogen ions had been produced to find the reaction rate. Bizarre Quantum Tunneling Observation Throws Out All the Rules 2023-04-04T04:00:00Z The pH value is a measure of hydrogen ion concentration in a solution and is one of many chemical characteristics that is highly regulated in living organisms through homeostasis. Biology for AP Courses 2022-06-09T00:00:00Z Metals with lower reduction potentials reduce the hydrogen ion in dilute acids to produce hydrogen gas and metal salts. Chemistry 2019-02-14T00:00:00Z Ammonium chloride gives off small amounts of ammonia, which moves inside the cell and raises the pH, making it more alkaline, which means fewer hydrogen ions. And then there were 6 -- kinds of taste, that is 2023-10-05T04:00:00Z The electrons are passed through a series of chemical reactions, with a small amount of free energy used at three points to transport hydrogen ions across the membrane. Concepts of Biology 2013-04-25T00:00:00Z To determine whether a solution is acidic or alkaline, we find its pH, which is a measure of the number of active positive hydrogen ions in the solution. College Algebra with Corequisite Support 2020-09-23T00:00:00Z Buffers absorb extra hydrogen ions to prevent increases or decreases in pH. Biology for AP Courses 2022-06-09T00:00:00Z Thus, hydrogen ion should not appear as a reactant or product in basic solution. Chemistry 2019-02-14T00:00:00Z When hydrogen ions in the wind strike oxygen-bearing minerals in lunar soil, it creates hydroxyl, which can be transformed into water through subsequent reactions. Stowaways on NASA’s massive Moon rocket promise big science in small packages 2022-08-15T04:00:00Z In both cases, this pH test measures the amount of hydrogen ions that exists in a given solution. Concepts of Biology 2013-04-25T00:00:00Z TRY IT #12 How does the pH change when the concentration of positive hydrogen ions is decreased by half? Algebra and Trigonometry 2015-02-13T00:00:00Z Still, by convention, scientists refer to hydrogen ions and their concentration as if they were free in this state in liquid water. Biology for AP Courses 2022-06-09T00:00:00Z The oxygen-hydrogen bond, bond b, is thereby weakened because electrons are displaced toward E. Bond b is polar and readily releases hydrogen ions to the solution, so the material behaves as an acid. Chemistry 2019-02-14T00:00:00Z When it accepts two high-energy electrons, NADP+ also bonds a hydrogen ion, which turns it into NADPH. Miller & Levine Biology 2018-01-01T00:00:00Z High concentrations of hydrogen ions yield a low pH, whereas low levels of hydrogen ions result in a high pH. Concepts of Biology 2013-04-25T00:00:00Z When the concentration of hydrogen ions is doubled, the pH decreases by about 0.301. Algebra and Trigonometry 2015-02-13T00:00:00Z Using the negative logarithm to generate positive integers, high concentrations of hydrogen ions yield a low pH number, whereas low levels of hydrogen ions result in a high pH. Biology for AP Courses 2022-06-09T00:00:00Z A coordinate covalent bond also results when an ammonia molecule combines with a hydrogen ion to form an ammonium ion. Chemistry 2019-02-14T00:00:00Z The electrons travel through this chain, and the resulting energy transports hydrogen ions through the membrane and into the intermembrane space. Miller & Levine Biology 2018-01-01T00:00:00Z Therefore, the more hydrogen ions present, the lower the pH; conversely, the fewer hydrogen ions, the higher the pH. Concepts of Biology 2013-04-25T00:00:00Z Thus, small changes in pH represent large changes in the concentrations of hydrogen ions. Environmental Biology 2018-09-06T00:00:00Z In cases where the base releases hydroxide ions, these ions bind to free hydrogen ions, generating new water molecules. Biology for AP Courses 2022-06-09T00:00:00Z Negative values for electrode potentials are simply a consequence of assigning a value of 0 V to the SHE, indicating the reactant of the half-reaction is a weaker oxidant than aqueous hydrogen ions. Chemistry 2019-02-14T00:00:00Z Oxygen will accept the electrons at the end of the chain and combine with hydrogen ions to form water. Miller & Levine Biology 2018-01-01T00:00:00Z This electron transport system uses the energy from the electron to pump hydrogen ions into the interior of the thylakoid. Concepts of Biology 2013-04-25T00:00:00Z The pH of a solution is a measure of the concentration of hydrogen ions in the solution. Environmental Biology 2018-09-06T00:00:00Z When bicarbonate ions combine with free hydrogen ions and become carbonic acid, hydrogen ions are removed, moderating pH changes. Biology for AP Courses 2022-06-09T00:00:00Z Aqueous solutions are basic because the carbonate ion accepts hydrogen ion from water in this reversible reaction: Chemistry 2019-02-14T00:00:00Z The hydrogen ions are forced through the ATP synthases, causing the base of the enzymes to spin. Miller & Levine Biology 2018-01-01T00:00:00Z The oxygen with its extra electrons then combines with two hydrogen ions, further enhancing the electrochemical gradient, to form water. Concepts of Biology 2013-04-25T00:00:00Z In the presence of oxygenated water, sulfides such as pyrite react undergo complex reactions to release metal ions and hydrogen ions, lowering pH to highly acidic levels. An Introduction to Geology 2017-01-01T00:00:00Z The removal of the hydrogen ions from the system contributes to the ion gradient used in the process of chemiosmosis. Biology for AP Courses 2022-06-09T00:00:00Z Polyprotic bases are capable of accepting more than one hydrogen ion. Chemistry 2019-02-14T00:00:00Z Each NAD+ molecule accepts a pair of high-energy electrons and a hydrogen ion. Miller & Levine Biology 2018-01-01T00:00:00Z ATP itself is formed through secondary active transport using a hydrogen ion gradient in the mitochondrion. Concepts of Biology 2013-04-25T00:00:00Z Step 3: When CO2 is available, the reaction is driven to the formation of carbonic acid, which dissociates to form a bicarbonate ion and a hydrogen ion. Anatomy and Physiology 2013-06-19T00:00:00Z The turning of parts of this molecular machine facilitates the addition of a phosphate to ADP, forming ATP, using the potential energy of the hydrogen ion gradient. Biology for AP Courses 2022-06-09T00:00:00Z Calculate the hydrogen ion concentration and the hydroxide ion concentration in wine from its pH. Chemistry 2019-02-14T00:00:00Z Water is split apart to make electrons available to PS II, which produces O2 and hydrogen ions. Miller & Levine Biology 2018-01-01T00:00:00Z As the electron passes along these proteins, energy from the electron fuels membrane pumps that actively move hydrogen ions against their concentration gradient from the stroma into the thylakoid space. Concepts of Biology 2013-04-25T00:00:00Z The hydrogen ion is secreted into the filtrate, where it can become part of new water molecules and be reabsorbed as such, or removed in the urine. Anatomy and Physiology 2013-06-19T00:00:00Z For example, the number of hydrogen ions that the electron transport chain complexes can pump through the membrane varies between species. Biology for AP Courses 2022-06-09T00:00:00Z For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. Chemistry 2019-02-14T00:00:00Z One water molecule can split apart to form one positive hydrogen ion, H+, and one negative hydroxide ion, OH–. Miller & Levine Biology 2018-01-01T00:00:00Z This potential energy is harvested and stored as chemical energy in ATP through chemiosmosis, the movement of hydrogen ions down their electrochemical gradient through the transmembrane enzyme ATP synthase, just as in the mitochondrion. Concepts of Biology 2013-04-25T00:00:00Z It is also possible that salts in the filtrate, such as sulfates, phosphates, or ammonia, will capture hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z Which statement best describes the formation and importance of the hydrogen ion gradient during the electron transport chain? Biology for AP Courses 2022-06-09T00:00:00Z Using this information, calculate the standard free energy change for the aqueous reaction of hydrogen ion with hydroxide ion to produce water. Chemistry 2019-02-14T00:00:00Z Using hydrogen ions and then removing the extra electrons further increases the beam density so that each bunch consists of roughly 120 billion protons squeezed into a diameter of about three microns. Large Hadron Collider Seeks New Particles after Major Upgrade 2022-04-27T04:00:00Z The energy generated by the hydrogen ion stream allows ATP synthase to attach a third phosphate to ADP, which forms a molecule of ATP in a process called photophosphorylation. Concepts of Biology 2013-04-25T00:00:00Z If this occurs, the hydrogen ions will not be available to combine with bicarbonate ions and produce CO2. Anatomy and Physiology 2013-06-19T00:00:00Z A hydrogen ion gradient across the membrane establishes a concentration gradient and not an electrical gradient, thus assisting during the electron transport chain. Biology for AP Courses 2022-06-09T00:00:00Z Why don’t hydrogen ions appear in equations for half-reactions occurring in basic solution? Chemistry 2019-02-14T00:00:00Z To make the deuteron and hydrogen ion orbit under the same conditions, Myers and Fink kept the two in the same electromagnetic trap for weeks at a time. Particle drag race leads to most precise estimate yet of the proton’s mass 2021-11-30T05:00:00Z In the electron transport chain, the free energy from the series of reactions just described is used to pump hydrogen ions across the membrane. Concepts of Biology 2013-04-25T00:00:00Z When this occurs, fewer hydrogen ions in the filtrate participate in the conversion of bicarbonate into CO2 and less bicarbonate is conserved. Anatomy and Physiology 2013-06-19T00:00:00Z A hydrogen ion gradient is established by pumping two hydrogen ions across the membrane from the matrix in the intermembrane space. Biology for AP Courses 2022-06-09T00:00:00Z The chemistry of these compounds is explored in more detail in later chapters of this text, but for now, it will suffice to note that many acids release hydrogen ions, H+, when dissolved in water. Chemistry 2019-02-14T00:00:00Z He and Fink generated the trapped hydrogen ion by using an electron beam to knock an electron out of a hydrogen molecule. Particle drag race leads to most precise estimate yet of the proton’s mass 2021-11-30T05:00:00Z Oxygen and hydrogen ions are also formed from the splitting of water. Concepts of Biology 2013-04-25T00:00:00Z If there is less potassium, more hydrogen ions enter the filtrate to be exchanged with sodium and more bicarbonate is conserved. Anatomy and Physiology 2013-06-19T00:00:00Z A hydrogen ion gradient is established by pumping four hydrogen ions across the membrane from the matrix into the intermembrane space and its uneven distribution across the membrane establishes concentration and electrical gradients. Biology for AP Courses 2022-06-09T00:00:00Z The chromium half-reaction shows 14 H atoms on the right and none on the left, so 14 hydrogen ions are added to the left side. Chemistry 2019-02-14T00:00:00Z Koelemeij says his team is using a laser to create and trap hydrogen ions in known vibrational and rotational states. Particle drag race leads to most precise estimate yet of the proton’s mass 2021-11-30T05:00:00Z The hydrogen ions play critical roles in the remainder of the light-dependent reactions. Concepts of Biology 2013-04-25T00:00:00Z Just as with sodium ions in salty flavors, these hydrogen ions enter the cell and trigger depolarization. Anatomy and Physiology 2013-06-19T00:00:00Z The electrons are passed through a series of redox reactions, with a small amount of free energy used at three points to transport hydrogen ions across a membrane. Biology for AP Courses 2022-06-09T00:00:00Z Consequently, the bonded water molecules' O–H bonds are more polar than in nonbonded water molecules, making the bonded molecules more prone to donation of a hydrogen ion: Chemistry 2019-02-14T00:00:00Z The Sun throws hydrogen ions at the lunar surface, in the form of the solar wind, that bombard oxygen-rich rocks, apparently forming small amounts of water. NASA-funded startups will soon put a fleet of landers on the Moon 2021-09-08T04:00:00Z Energy travels through the electron transport chain, which pumps hydrogen ions into the thylakoid space. Concepts of Biology 2013-04-25T00:00:00Z In contrast, if pH rises above 7.45, the buffer will act as a weak acid and contribute hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z To return to the example of excess hydrogen ions in the blood, the formation of carbonic acid will be the major direction of the reaction. Biology for AP Courses 2022-06-09T00:00:00Z To improve electrical conductivity without introducing a different redox species, the hydrogen ion concentration of the water is typically increased by addition of a strong acid. Chemistry 2019-02-14T00:00:00Z However, the precision of this theory’s predictions of rotational and vibrational frequencies of molecular hydrogen ions is severely hampered by the observed mass discrepancies7,8. Precise measurement of deuteron mass raises hopes of solving the nuclear-mass puzzle 2020-09-01T04:00:00Z A nickel catalyst on the inner surface of the tube produces positively charged hydrogen ions, electrons, and CO2. New reactor could halve carbon dioxide emissions from ammonia production 2019-11-06T05:00:00Z Because an atom of hydrogen has just one proton and one electron, a positively charged hydrogen ion is simply a proton. Anatomy and Physiology 2013-06-19T00:00:00Z Therefore, a concentration gradient forms in which hydrogen ions diffuse out of the matrix space by passing through ATP synthase. Biology for AP Courses 2022-06-09T00:00:00Z Ionic oxides all contain the oxide ion, a very powerful hydrogen ion acceptor. Chemistry 2019-02-14T00:00:00Z The membrane only allows hydrogen ions to pass to the other catalyst-coated electrode, the cathode, where they meet up with electrons to generate H2 gas. Can the world make the chemicals it needs without oil? 2019-09-19T04:00:00Z Meanwhile, on the tube’s outer surface, the second catalyst—which contains vanadium, nitrogen, and iron—causes the hydrogen ions, the electrons, and nitrogen molecules piped in separately to form ammonia, all at atmospheric pressure. New reactor could halve carbon dioxide emissions from ammonia production 2019-11-06T05:00:00Z Weak acids do not ionize completely; that is, some of their hydrogen ions remain bonded within a compound in solution. Anatomy and Physiology 2013-06-19T00:00:00Z If the membrane were open to diffusion by the hydrogen ions, the ions would tend to diffuse back across into the matrix, driven by their electrochemical gradient. Biology for AP Courses 2022-06-09T00:00:00Z Researchers believe that in that primordial gas, neutral helium reacted with hydrogen ions to form the first chemical bond joining the very first molecule. Astronomers have spotted the universe’s first molecule 2019-04-17T04:00:00Z Dr. Boyer showed how the presence of hydrogen ions transformed the components of ATP through a chemical synthesis into the complete ATP molecule. Paul D. Boyer, UCLA biochemist who won Nobel Prize in 1997, dies at 99 2018-06-06T04:00:00Z This collection of negative charges, in turn, pulls the positively charged hydrogen ions through the wall of the ceramic membrane to the tube’s outer surface. New reactor could halve carbon dioxide emissions from ammonia production 2019-11-06T05:00:00Z Acidosis is a condition in which excess hydrogen ions are present, and the patient’s blood expresses a low pH value. Anatomy and Physiology 2013-06-19T00:00:00Z This complex protein acts as a tiny generator, turned by the force of the hydrogen ions diffusing through it, down their electrochemical gradient. Biology for AP Courses 2022-06-09T00:00:00Z The greater the concentration of hydrogen ions, the lower the pH of the water will be and the more acidic the conditions. Sea change : Nature : Nature Research 2017-10-10T04:00:00Z With this approach, the Dehmelt team recorded hyperfine spectra of trapped helium ions and molecular hydrogen ions with unprecedented resolution. Hans Dehmelt (1922-2017) : Nature : Nature Research 2017-05-16T04:00:00Z Oxygen gas comes bubbling off the cobalt oxide sites, while positively charged hydrogen ions migrate to the platinum particles. The new breed of cutting-edge catalysts 2016-09-05T04:00:00Z Alkalosis is a condition in which there are too few hydrogen ions, and the patient’s blood has an elevated pH. Anatomy and Physiology 2013-06-19T00:00:00Z To release this energy, hydrogen ions will rush through any opening, similar to water jetting through a hole in a dam. Biology for AP Courses 2022-06-09T00:00:00Z Because pH is measured on a logarithmic scale, every change of 0.1 units results in a 26% increase in concentration of hydrogen ions. Sea change : Nature : Nature Research 2017-10-10T04:00:00Z That allows the instrument to capture light emitted by excited hydrogen ions at the poles. We just got our closest look ever at Jupiter’s north pole thanks to NASA’s Juno spacecraft 2016-09-02T04:00:00Z According to Ashcroft, the light hydrogen ions would shake with very high frequency phonons, the key to boosting the transition temperature. Stinky hydrogen sulfide smashes superconductivity record 2015-08-17T04:00:00Z The concentration of hydrogen ions at each pH value is 10 times different than the next pH. Anatomy and Physiology 2013-06-19T00:00:00Z The energy travels to the reaction center that contains chlorophyll a and then to the electron transport chain, which pumps hydrogen ions into the thylakoid interior. Biology for AP Courses 2022-06-09T00:00:00Z Ocean acidification interferes with shell formation because hydrogen ions in sea water react with carbonate ions, forming bicarbonate ions. Sea change : Nature : Nature Research 2017-10-10T04:00:00Z Afterwards, we perform similar measurements with the hydrogen ion to determine ≈ 29.635 MHz. High-precision comparison of the antiproton-to-proton charge-to-mass ratio : Nature : Nature Publishing Group 2015-08-11T04:00:00Z The zinc reduces hydrogen ions to produce bubbles of hydrogen gas. Self-Propelled Micromotors Take Their First Swim in the Body 2015-01-23T05:00:00Z The greater the amount of carbon dioxide in the blood, the more molecules that must be converted, which in turn generates hydrogen ions and thus lowers blood pH. Anatomy and Physiology 2013-06-19T00:00:00Z In both cases, the pH test measures the concentration of hydrogen ions in a given solution. Biology for AP Courses 2022-06-09T00:00:00Z Many organisms have mechanisms to regulate internal pH, such as pumping hydrogen ions in or out. Sea change : Nature : Nature Research 2017-10-10T04:00:00Z The probability of the bicarbonate and hydrogen ions doing this is affected by temperature: the higher the temperature, the faster the molecules move; the lower the temperature, the slower they move. Carbonation Countdown: The Effect of Temperature of Reaction Time 2013-08-29T15:15:00.733Z This liberates hydrogen ions for the acidity, turns insoluble sulfide into very soluble sulfate, and creates rust from reduced iron, a fascinating, if annoying, chemical process. Fracking With Bad Water 2013-02-04T07:21:11Z Increased metabolic byproducts associated with increased activity, such as carbon dioxide, hydrogen ions, and lactic acid, plus falling oxygen levels, are detected by a suite of chemoreceptors innervated by the glossopharyngeal and vagus nerves. Anatomy and Physiology 2013-06-19T00:00:00Z This prevents too many free hydrogen ions from building up in the blood and dangerously reducing the blood’s pH. Biology for AP Courses 2022-06-09T00:00:00Z Five of the eleven families encoding hydrogen ion transmembrane transporters were significantly more numerous in than in wheat. Analysis of the bread wheat genome using whole-genome shotgun sequencing 2012-11-28T18:21:17.300Z Those energized electrons are then passed to the catalyst, which knits the hydrogen ions into H2. A Wet Way to Better Burning? 2012-11-08T22:20:21Z Machines with newer technology, such as Life Technologies’ Personal Genome Machine and Ion Proton sequencers, sense the different chemical bases by measuring the release of hydrogen ions from each “letter” of the DNA alphabet. Genome Cure for Ill Twins Paves Way to Doctor’s Office 2012-01-31T00:57:10Z This cluster of neurons responds to changes in blood pressure as well as blood concentrations of oxygen, carbon dioxide, and hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z They are bases because they contain an amino group that has the potential of binding an extra hydrogen, thus decreasing the hydrogen ion concentration in its environment, making it more basic. Biology for AP Courses 2022-06-09T00:00:00Z An indicator, like anthocyanin, responds to the levels of hydrogen ions in the solution. Cabbage Chemistry--Finding Acids and Bases 2012-01-26T15:45:00.393Z In the wells in which the sensor detects a hydrogen ion, the ion shows that the DNA that the DNA polymerase added an A to its growing strand. A $1000 Genome by 2013? 2011-07-20T21:35:09Z It is regulated by a group of nerve fibers, the so-called ergoreceptors, that respond to a combination of metabolites released by muscles during exercise — calcium ions, lactate, hydrogen ions. Personal Best: One Runner?s Suffering Is Another?s Inspiration 2011-05-16T15:12:59Z Concentration changes in certain substances, such as carbon dioxide or hydrogen ions, stimulate these receptors, which in turn signal the respiration centers of the brain. Anatomy and Physiology 2013-06-19T00:00:00Z This secondary process is also used to store high-energy hydrogen ions in the mitochondria of plant and animal cells for the production of ATP. Biology for AP Courses 2022-06-09T00:00:00Z Depending on the levels of hydrogen ions in the solution, the indicator pigment undergoes a chemical reaction that changes its chemical structure, making it reflect a different wavelength of light and thereby change color. Cabbage Chemistry--Finding Acids and Bases 2012-01-26T15:45:00.393Z Owing to the nature of their charges, the hydrogen ions will move towards the negative electrode, and the SO4 ions towards the positive electrode. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z Electrons must be stripped from hydrogen atoms in water, which causes water molecules to fracture into positively charged hydrogen ions, or protons, and negatively charged oxygen atoms. Spinning the Sun's Rays Into Fuel 2011-03-28T20:30:02Z As will be explained in more detail later, increased carbon dioxide levels lead to increased levels of hydrogen ions, decreasing pH. Anatomy and Physiology 2013-06-19T00:00:00Z The potential energy that accumulates in the stored hydrogen ions is translated into kinetic energy as the ions surge through the channel protein ATP synthase, and that energy is used to convert ADP into ATP. Biology for AP Courses 2022-06-09T00:00:00Z Acids are solutions that lose hydrogen ions and usually taste sour. Cabbage Chemistry--Finding Acids and Bases 2012-01-26T15:45:00.393Z These laws are explained very naturally if we make the assumption that electricity, like matter, is atomic, the atom being the charge carried by the hydrogen ion. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z It is evident that the undissociated part of each acid must eventually be in equilibrium with the free hydrogen ions, and, if the concentrations are not such as to secure this condition, readjustment must occur. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z The increase in hydrogen ions in the brain triggers the central chemoreceptors to stimulate the respiratory centers to initiate contraction of the diaphragm and intercostal muscles. Anatomy and Physiology 2013-06-19T00:00:00Z The electrons pass through a series of redox reactions, using free energy at three points to transport hydrogen ions across the membrane. Biology for AP Courses 2022-06-09T00:00:00Z How basic or acidic a solution is depends on the amount of hydrogen ions in it. Cabbage Chemistry--Finding Acids and Bases 2012-01-26T15:45:00.393Z But the Ion Torrent machine uses a silicon chip that can detect the hydrogen ions given off when a new base is added to a strand of DNA. Taking DNA Sequencing to the Masses 2011-01-05T00:25:15Z In order that there should be no change in the states of dissociation on mixing, it is necessary, therefore, that the concentration of the hydrogen ions should be the same in each separate solution. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z In contrast, low levels of carbon dioxide in the blood cause low levels of hydrogen ions in the brain, leading to a decrease in the rate and depth of pulmonary ventilation, producing shallow, slow breathing. Anatomy and Physiology 2013-06-19T00:00:00Z This causes hydrogen ions to accumulate within the matrix space. Biology for AP Courses 2022-06-09T00:00:00Z Ocean acidification has further chemical implications: more hydrogen ions mean more bicarbonate ions, and fewer carbonate ions. Ocean acidification: The other carbon-dioxide problem 2010-07-01T11:08:00Z They showed that one element controlling blood circulation in the brain is the acidity, or hydrogen ion, concentration. Fred Plum, Neurologist Who Helped Coin ?Persistent Vegetative State,? Dies at 86 2010-06-12T23:26:00Z Some acetic acid is formed, and this process will go on till the solutions of the two acids are isohydric: that is, till the dissociated hydrogen ions are in equilibrium with both. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Another factor involved in influencing the respiratory activity of the brain is systemic arterial concentrations of hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z Then, in the second half-reaction, the electrons and hydrogen ions combine with carbon dioxide to create energy-rich carbohydrates, such as glucose, which plants use to grow. Artificial photosynthesis: A sunnier outlook 2010-04-29T11:22:00Z The acidity of an electrolytic solution is due to the presence of the dissociated ion H+, and its strength is determined by the concentration of these free hydrogen ions. The Mechanism of Life The hydrogen ions from the anode vessel of acid were thus carried along the tube, and, as they travelled, decolourized the phenol-phthalein. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 8 "Conduction, Electric" A later development, the Van de Graaff electrostatic generator, produced a beam of hydrogen ions and other positively charged ions, and electrons at even higher energies. A Brief History of Element Discovery, Synthesis, and Analysis Peripheral chemoreceptors of the aortic arch and carotid arteries sense arterial levels of hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z The sulphuric acid has molecules which split up in solution, as you remember, into hydrogen ions and the ions which we called “sulphate.” Letters of a Radio-Engineer to His Son Acids yielding two hydrogen ions in solution are called dibasic acids. An Elementary Study of Chemistry That reddish glow looked like hydrogen ions in the air. The Black Star Passes Thus, in the simple cell under consideration the sulphuric acid, by dissociation, splits up into hydrogen ions bearing positive charges, and SO4 ions bearing negative charges. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Removal of carbon dioxide from the blood helps to reduce hydrogen ions, thus increasing systemic pH. Anatomy and Physiology 2013-06-19T00:00:00Z But if the sulphate ions get tied up 31with the lead of the plate there will be too many hydrogen ions left in the solution. Letters of a Radio-Engineer to His Son It forms hydrogen ions in solution and neutralizes bases forming salts. An Elementary Study of Chemistry The unit charge is that which is dissociated with a hydrogen ion. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes The hydrogen ions also compete with potassium to exchange with sodium in the renal tubules. Anatomy and Physiology 2013-06-19T00:00:00Z This causes more hydrogen ions to be produced, causing the blood pH to drop. Anatomy and Physiology 2013-06-19T00:00:00Z Now what are the hydrogen ions to do? Letters of a Radio-Engineer to His Son Such acids as hydrochloric and nitric acids, which have only one replaceable hydrogen atom in the molecule, or in other words yield one hydrogen ion in solution, are called monobasic acids. An Elementary Study of Chemistry Hydrogen sulphide is a weak acid, and the concentration of the hydrogen ions in its aqueous solutions is very small. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes If more potassium is present than normal, potassium, rather than the hydrogen ions, will be exchanged, and increased potassium enters the filtrate. Anatomy and Physiology 2013-06-19T00:00:00Z This combination forms carbonic acid, which spontaneously dissociates into bicarbonate and hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z When the hydrogen ions try to get away from each other they go to the other plate of the battery, and there they will get some electrons, if they have to steal in their turn. Letters of a Radio-Engineer to His Son Thus, in the general reaction between an acid and a base, the essential action is between the univalent hydrogen ion and the univalent hydroxyl ion. An Elementary Study of Chemistry The respiratory and renal systems also play major roles in acid-base homeostasis by removing CO2 and hydrogen ions, respectively, from the body. Anatomy and Physiology 2013-06-19T00:00:00Z This means that lemon juice has a one hundred-fold greater concentration of hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z Note how the hydrogen ion is recycled so that bicarbonate can be recovered. Anatomy and Physiology 2013-06-19T00:00:00Z The hydrogen ions get the electrons which they need, but they get something more. Letters of a Radio-Engineer to His Son In solution this substance can give hydrogen ions, and therefore possesses acid properties; it can also give the ions characteristic of a salt. An Elementary Study of Chemistry Bicarbonate is created by a chemical reaction that occurs mostly in erythrocytes, joining carbon dioxide and water by carbonic anhydrase, producing carbonic acid, which breaks down into bicarbonate and hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z Sodium ions are reabsorbed at the membrane, and hydrogen ions are expelled into the filtrate. Anatomy and Physiology 2013-06-19T00:00:00Z A buffer is a chemical system that prevents a radical change in fluid pH by dampening the change in hydrogen ion concentrations in the case of excess acid or base. Anatomy and Physiology 2013-06-19T00:00:00Z We call each a “hydrogen ion” but you can see that each is a single proton. Letters of a Radio-Engineer to His Son But since water is almost entirely undissociated, equilibrium can only be reached when there are very few hydroxyl or hydrogen ions present. An Elementary Study of Chemistry The hydrogen ions combine with bicarbonate, forming carbonic acid, which dissociates into CO2 gas and water. Anatomy and Physiology 2013-06-19T00:00:00Z Neural mechanisms include the cardiovascular centers in the medulla oblongata, baroreceptors in the aorta and carotid arteries and right atrium, and associated chemoreceptors that monitor blood levels of oxygen, carbon dioxide, and hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z Most commonly, the substance that absorbs the ions is either a weak acid, which takes up hydroxyl ions, or a weak base, which takes up hydrogen ions. Anatomy and Physiology 2013-06-19T00:00:00Z In the upper part of the liquid in the jar, therefore, there are sulphate 25ions which are negative and two kinds of positive ions, namely, the hydrogen ions and the zinc ions. Letters of a Radio-Engineer to His Son DEFINITION: An acid is a substance which produces hydrogen ions when dissolved in water or other dissociating liquids. An Elementary Study of Chemistry Some of the positive ions, therefore, and particularly the hydrogen ions, because the sulphate prefers to associate with the zinc ions, can’t find enough playfellows and so go down in the jar. Letters of a Radio-Engineer to His Son Down in the bottom of the jar the hydrogen ions find more sulphate ions to play with, but that leaves the copper ions which used to play with these sulphate ions without any playmates. Letters of a Radio-Engineer to His Son The kidneys help control acid-base balance by excreting hydrogen ions and generating bicarbonate that helps maintain blood plasma pH within a normal range. Anatomy and Physiology 2013-06-19T00:00:00Z Before the zinc ions began to crowd in there were just enough hydrogen ions to go with the sulphate ions. Letters of a Radio-Engineer to His Son Many salts such as those of antimony and bismuth form solutions which are somewhat acid in reaction, and must therefore contain hydrogen ions. An Elementary Study of Chemistry What are the hydrogen ions going to do? Letters of a Radio-Engineer to His Son In the process of electrolysis of the solution, the hydrogen ions travel to the cathode, and on being discharged escape as hydrogen gas. An Elementary Study of Chemistry |
| 随便看 |
|
英语例句辞典收录了117811条英语例句在线翻译词条，基本涵盖了全部常用单词及词组的例句翻译及用法，是英语学习的有利工具。