In chemistry, phosphorylation of a molecule is the attachment of a phosphoryl group. Together with its counterpart, dephosphorylation, it is critical for many cellular processes in biology. Phosphorylation is important for protein function. Many proteins are phosphorylated temporarily, as are many sugars and other biologically-relevant molecules. Phosphorylation of sugars is the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism because many sugars are first converted to glucose before they are metabolized further; the chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by D-glucose + ATP → D-glucose-6-phosphate + ADPΔG° = −16.7 kJ/mol Researcher D. G. Walker of the University of Birmingham determined the presence of two specific enzymes in adult guinea pig liver, both of which catalyze the phosphorylation of glucose to glucose 6 phosphate.

The two enzymes have been identified as a specific non-specific hexokinase. Hepatic cells are permeable to glucose, the initial rate of phosphorylation of glucose is the rate-limiting step in glucose metabolism by the liver and non-specific hexokinase; the role of glucose 6-phosphate in glycogen synthase: High blood glucose concentration causes an increase in intracellular levels of glucose 6 phosphate in liver, skeletal muscle and fat tissue. And non-specific hexokinase. In liver, synthesis of glycogen is directly correlated by blood glucose concentration and in skeletal muscle and adipocytes, glucose has a minor effect on glycogen synthase. High blood glucose releases insulin, stimulating the trans location of specific glucose transporters to the cell membrane; the liver’s crucial role in controlling blood sugar concentrations by breaking down glucose into carbon dioxide and glycogen is characterized by the negative delta G value, which indicates that this is a point of regulation with. The hexokinase enzyme has a low Km, indicating a high affinity for glucose, so this initial phosphorylation can proceed when glucose levels at nanoscopic scale within the blood.

The phosphorylation of glucose can be enhanced by the binding of Fructose-6-phosphate, lessened by the binding fructose-1-phosphate. Fructose consumed in the diet is converted to F1P in the liver; this negates the action of F6P on glucokinase, which favors the forward reaction. The capacity of liver cells to phosphorylate fructose exceeds capacity to metabolize fructose-1-phosphate. Consuming excess fructose results in an imbalance in liver metabolism, which indirectly exhausts the liver cell’s supply of ATP. Allosteric activation by glucose 6 phosphate, which acts as an effector, stimulates glycogen synthase, glucose 6 phosphate may inhibit the phosphorylation of glycogen synthase by cyclic AMP-stimulated protein kinase. Phosphorylation of glucose is imperative in processes within the body. For example, phosphorylating glucose is necessary for insulin-dependent mechanistic target of rapamycin pathway activity within the heart; this further suggests a link between cardiac growth. Glycolysis is an essential process of glucose degrading into two molecules of pyruvate, through various steps, with the help of different enzymes.

It occurs in ten steps and proves that phosphorylation is a much required and necessary step to attain the end products. Phosphorylation initiates the reaction in step 1 of the preparatory step, initiates step 6 of payoff phase. Glucose, by nature, is a small molecule with the ability to diffuse in and out of the cell. By phosphorylating glucose, glucose is converted to glucose-6-phosphate and trapped within the cell as the cell membrane is negatively charged; this reaction occurs due to the enzyme hexokinase, an enzyme that helps phosphorylate many six-membered ring structures. Glucose-6-phosphate cannot travel through the cell membrane and is therefore, coerced to stay inside the cell. Phosphorylation takes place in step 3, where fructose-6-phosphate is converted to fructose-1,6-bisphosphate; this reaction is catalyzed by phosphofructokinase. While phosphorylation is performed by ATPs during preparatory steps, phosphorylation during payoff phase is maintained by inorganic phosphate; each molecule of glyceraldehyde-3-phosphate is phosphorylated to form 1,3-bisphosphoglycerate.

This reaction is catalyzed by GAPDH. The cascade effect of phosphorylation causes instability and allows enzymes to open the carbon bonds in glucose. Phosphorylation functions as an vital component of glycolysis, for it helps in transport and efficiency. Protein phosphorylation is considered the most abundant post-translational modification in eukaryotes. Phosphorylation can occur on serine and tyrosine side chains through phosphoester bond formation, on histidine and arginine through phosphoramidate bonds, on aspartic acid and glutamic acid through mixed anhydride linkages. Recent evidence confirms widespread histidine phosphorylation at both the 1 and 3

YellowPagesDirectory.Com, is an American website that features a national online telephone number and street address directory, containing Yellow Pages and White Pages throughout the United States. Known as, is owned and operated by Yellow Pages Directory Inc., headquartered in Manhattan, NY. The website was launched in 2010 by a private owner and was soon acquired by Yellow Pages Directory Inc. In addition to telephone and street address listings, the website touts an environmentally friendly theme and features numerous informational blog articles on the subject of conversation, in addition to being outspoken advocates of opting-out of traditional print telephone directory home delivery. is an online search engine and telephone directory with an "environmentally friendly" marketing standpoint. They encompass yellow and residential pages and feature over 28.5 million business listings throughout the United States. Users of the site are able to add and delete their Business and Residential listings.

In addition, has a digital coupon collecting and sharing app available for both Android and iPhone devices. touts itself as a purely digital alternative to traditional print telephone directories. As a web-based service, their marketing claim is that they do not generate the large amount of paper-based waste associated with physical directory media such as telephone books. Paper directories have long been cited as a source of waste in society. In addition, the service states that they update their listings on a daily basis, keeping them current, whereas print phone directories are only manufactured periodically and therefore do not always offer up-to-date directory information. As an example, an article published by Forbes by writer Tom Barlow entitled "Yellow Pages: No More Waste on the Stoop," touts the internet as the clear and present successor of print yellow pages. Another service provides for users is the ability for anyone nationwide to “opt-out” of local telephone book delivery.

The site features a updated Blog that features articles of an environmental nature, such as organic crop growing, hybrid vehicles, ways to avoid pollution. Since its purchase of, Yellow Pages Directory, Inc. was approved to be treated as a private S-corporation by the New York State Department of State Division of Corporation effective May 20, 2010, has been an accredited member of the Better Business Bureau since July 15, 2011. The website that would become launched in April, 2010 as On September 16, 2010, it was announced that had been acquired by Yellow Pages Directory, Inc. and subsequently re-branded as, with the headquarters moved to East Northport, NY. Yellow Pages Directory, Inc. owner Michael Keegan said that he saw in the purchase the potential to cater to the growing environmentally conscious movement prevailing throughout the United States. Keegan attended Farmingdale State College and Oakdale's Dowling College, where he graduated with a BA in Business Administration.

Starting out as a United States Yellow Page Business Directory, added Canadian listings in July 2012, in addition to Residential White Page listings in March 2013. A Smartphone App for Android and iPhone devices dubbed the “Best Coupon App,” which allows users to search for and share local coupons with their mobile devices, doing away with the need for paper coupons. In June 2019, Yellow Pages Directory, Inc. the parent company of, announced the re-branding of the website to reflect their corporate name in what owners stated was a bid to reduce confusion among consumers. The new headquarters is located in Manhattan, NY; the homepage was redesigned to reflect the change and a new focus on business marketing while maintaining the directory’s emphasis on environmental causes, the majority of the content was incorporated into new site's "opt out" page

2019 WTA Elite Trophy

The 2019 WTA Elite Trophy was a women's tennis tournament played at the Hengqin International Tennis Center in Zhuhai, China. It doubles competition; the tournament was contested by six doubles teams. WTA Elite Trophy is an invitation-only event; the field consisted of the top 11 players not qualified for the 2019 WTA Finals, plus either the 12th-player not qualified for 2019 WTA Finals, or a wild card. The final two alternates for the 2019 WTA Finals were eligible to play in WTA Elite Trophy if they had participated in the WTA Finals. Point totals were calculated by combining points obtained from 16 tournaments. Of these 16 tournaments, a player's results from the four Grand Slam events, the four Premier Mandatory tournaments, the best results from two Premier 5 tournaments had to be included. Two teams composed of players that did not compete in the WTA Finals singles or doubles competitions, using the players’ combined doubles rankings as of the Monday after the final regular-season Tournament of the current Tour Year to determine the order of acceptance.

Plus two wild cards. For each wild card not given out, the next highest pair of players would become a participant; the singles event featured 12 players in a round robin event, split into four groups of three. Over the first four days of competition, each player met the other two players in her group, with the winner in each group advancing to the semifinal; the winners of each semifinal met in the championship match. The six doubles teams were split into two round robin groups, with the winner of each advancing to the final; the final standings of each group were determined by the first of the following methods that apply: Greatest number of wins. Greatest number of matches played. In case of a 2-way tie: Head-to-head results In case of a 3-way tie: Percentage of sets won Head-to-head results Percentage of games won Head-to-head results Finals Rankings Stefi Graf; the total prize money for the 2019 WTA Elite Trophy Zhuhai was US$2,419,844. 1 RR means prize money or points won in the round robin.

2 Doubles doesn't award ranking points Kiki Bertens had another stellar season following on from the success she enjoyed in 2018. She won two more titles during the season in St. Petersburg and Madrid, the latter being the biggest of her career so far, she reached two finals in Rosmalen and Palermo. She had five semifinal appearances during the season in Sydney, Rome and Beijing, she reached three quarterfinals in Doha and Moscow. However, her grand slam results were disappointing as she lost in the second round in Australian Open and French Open and third round in Wimbledon and US Open, she narrowly missed qualifying for WTA Finals in Shenzhen. Bertens would be making her second appearance in Zhuhai having lost in the round robin stage in 2016. Sofia Kenin had a breakthrough season in 2019, she won two more titles during the season in Guangzhou. She reached a final in Acapulco and back to back semifinals in premier 5 level tournaments in Toronto and Cincinnati, she reached a quarterfinal in Zhengzhou, finishing the season inside the top 15.

Her grand slam breakthrough came at the French Open where she defeated Serena Williams en route to reaching the fourth round. She made the third round of US Open and second round of Australian Open and Wimbledon. Kenin was making her debut appearance in Zhuhai. Madison Keys had an up and down season, marked by numerous early exits but title wins in Cincinnati, her biggest career title and Charleston, her first clay court title, she reached a quarterfinal at French Open and in Osaka, finishing the season inside the top 20 for the fourth straight year. At the other majors, she made the fourth round of Australian Open and US Open and second round of Wimbledon. Keys was making her third appearance in Zhuhai, having bowed out in the round robin stage in 2015 and 2018. Aryna Sabalenka had a mixed season in 2019, with extreme lows, she defended her title in premier 5 level event in Wuhan in addition to winning a title in Shenzhen during the first week of the season. She reached a final in San Jose and semifinals in St. Petersburg and Strasbourg.

She reached quarterfinals in Eastbourne and Zhengzhou, finishing the season inside the top 20 for the second straight year. Her performance at grand slam events was disappointing with a third round loss at the Australian Open, second round defeats in French Open and US Open and a first round loss at Wimbledon. Sabalenka was making her second appearance in Zhuhai, having narrowly missed a chance to reach the semifinals last year. Petra Martić enjoyed her career best season, she made a final in Zhengzhou and semifinals in Charleston and Birmingham. She reached quarterfinals in Madrid and the French Open, her first grand slam quarterfinal, her performance at other grand slam events was encouraging with a fourth round loss at Wimbledon and US Open to go with a third round appearance in Australian Open. Martić was making her debut in Zhuhai. Elise Mertens carried on from she left