User:Bilal.bhatti96/sandbox

Week 3 Tasks - Info for tris(2,2'-bipyridine)iron(II) chloride (2019)

Properties of tris(2,2'-bipyridine)iron(II) chloride

• Molecular formula - C₃₀H₂₄Cl₂FeN₆
• Molar mass - 595.309 g/mol

Tris(2,2'-bipyridine)iron(II) chloride Tris(2,2'-bipyridine)iron(II) chloride

Carbonic anhydrase

[1]

References

"State of the art in eukaryotic nitrogenase engineering"

"Mechanism of N2 Reduction Catalyzed by Fe-Nitrogenase Involves Reductive Elimination of H2"

"Functional expression of an oxygen-labile nitrogenase in an oxygenic photosynthetic organism"

Properties of tris(2,2'-bipyridine)iron(II) chloride
Molecular Formula	C30H24Cl2FeN6
Molar Mass	595.309 g/mol
Heavy Atom Count	39

$1/4+(4)^{2}-V_{2}$

Chemical structure of Tris(2,2'-bipyridine)iron(II) chloride

Tris(2,2'-bipyridine)iron(II) chloride

Names
IUPAC name Iron(2+);2-pyridin-2-ylpyridine;dichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Carbonic Anhydrase - 2019

An enzyme is known as a substance that acts as a catalyst in living organisms which helps to speed up chemical reactions. Carbonic anhydrase is one important enzyme that is found in red blood cells, gastric mucosa, pancreatic cells, and even renal tubules. It is a very old enzyme that was discovered in the year 1932 and it has been categorized into three general classes. Class one being alpha carbonic anhydrase which is found in mammals, class two being beta carbonic anhydrase which is found in bacteria and plants and lastly, class 3 which is gamma carbonic anhydrase which is found in methanogen bacteria in hot springs. The three classes of carbonic anhydrase all have the same active site with a Zn metal centre however they are not structurally similar to each other. The main role of carbonic anhydrase in humans is to catalyze the conversion of carbon dioxide to carbonic acid and back again. However, it can also help with CO₂ transport in the blood which in turn helps respiration. It can even function in the formation of hydrochloric acid by the stomach. Therefore the role of carbonic anhydrase depends on where it is found in the body. The reaction that shows the catalyzation of carbonic anhydrase in our tissues is: CO₂ + H₂O $\longrightarrow$ H₂CO₃ $\longrightarrow$ H⁺ + HCO₃^-. The catalyzation of carbonic anhydrase in the lungs is shown by: H⁺ + HCO₃^-$\longrightarrow$H₂CO₃ $\longrightarrow$ CO₂ + H₂O. The reason for the reactions being in opposite directions for the tissues and lungs is because of the different pH levels found in them. Without the carbonic anhydrase catalyst, the reaction is very slow, however with the catalyst the reaction is 10⁷ times faster.

Additonal 250+400 word equivalents 2019

The Bohr Effect is a way to describe hemoglobin’s oxygen binding affinity. The Bohr Effect was described by Christian Bohr in the year 1904, and it refers to a shift in an oxygen dissociation curve that is caused by a change in concentration of carbon dioxide or a change in the pH. Essentially an increase in carbon dioxide results in lowered blood pH which lowers oxygen-hemoglobin binding. The opposite is true where a decrease in the concentration of carbon dioxide raises the blood pH which raises the rate of oxygen-hemoglobin binding. Relating the Bohr Effect to carbonic anhydrase is simple: carbonic anhydrase speeds up the reaction of carbon dioxide reacting with water to produce hydrogen protons and bicarbonate ions.

To describe equilibrium in the carbonic anhydrase reaction, Le Chatelier’s principle is used. The tissues are more acidic than the lungs because of the fact that carbon dioxide is produced by respiration and it reacts with water in the tissues to produce the hydrogen protons. Due to the fact that the carbon dioxide concentration is higher, equilibrium shifts to the right, to the bicarbonate side. The opposite is seen in the lungs where carbon dioxide is being released so its concentration is lower so equilibrium shifts to the left towards carbon dioxide to try and raise its concentration.

This image shows the cyclic mechanism for carbonic anhydrase.

This image shows the ligands and pocket style of carbonic anhydrase.

Properties of tris(2,2'-bipyridine)iron(II) chloride

• Molecular formula - C₃₀H₂₄Cl₂FeN₆
• Molar mass - 595.309 g/mol

Tris(2,2'-bipyridine)iron(II) chloride - 2,2'-Bipyridine

tris(2,2'-bipyridine)iron(II) chloride {{[2]

References

"Potential model systems for the nitrogenase enzyme"

"Nitrogenase: Standing at the crossroads"

"Effects of growth irradiance and nitrogen limitation on photosynthetic energy conversion in Photosystem II"

Tris(2,2'-bipyridine)iron(II) chloride
Molecular formula	C30H24Cl2FeN6
Molecular weight	595.309 g/mol
IUPAC Name	iron(2+);2-pyridin-2-ylpyridine;dichloride

${\frac {1}{4}}+{\frac {2}{4}}={\frac {3}{4}}$

$2^{4}$= 16

$C_{2}H_{4}$

Tris(2,2'-bipyridine)iron(II) chloride

Tris(2,2'-bipyridine)iron(II) chloride

Names
IUPAC name Iron(2+);2-pyridin-2-ylpyridine;dichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Carbonic Anhydrase

Carbonic anhydrase is an enzyme that was initially found in the year 1933 in the red blood cells of cows, and then later found in human and animal tissues, plants, algae and even bacteria. The role of carbonic anhydrase is to catalyze the hydration of carbon dioxide to bicarbonate ions, carbonic acid and protons.The reaction mechanism for the interconversion between carbon dioxide and water to carbonic acid and protons and bicarbonate ions can be shown as: CO₂ + H₂O ↔ H₂CO₃ ↔ H⁺ + HCO₃^- This mechanism shows that everything is always in equilibrium. In our tissues, carbon dioxide and water get converted to carbonic acid and then to bicarbonate and protons. The reverse of this mechanism is true when carbon dioxide is being expelled from our body because back in the lungs carbonic anhydrase converts bicarbonate ions and protons back to carbonic acid and then to carbon dioxide and water and is promptly expelled.

There are three main types of carbonic anhydrases that can be found: alpha carbonic anhydrase, beta carbonic anhydrase and gamma carbonic anhydrase. Alpha carbonic anhydrase is found in humans, beta carbonic anhydrase is found in prokaryotes and plants, and gamma carbonic anhydrase can be found in methanogen bacteria that grow in hot springs.

The human body can undergo the conversion of carbon dioxide to carbonic acid without the enzyme but with it, the interconversion occurs at a much faster rate. In the human body, carbonic anhydrase can regulate pH and fluid balance for example. Depending on which tissue or cellular compartment carbonic anhydrase is found in mammals, the role of the enzyme changes slightly. These are called isozymes. For example, carbonic anhydrase produces acid in our stomach lining, and even keeps our saliva neutral. If certain carbonic anhydrase isozymes are not performing its function, for example in the kidney where the control of bicarbonate ions influences the water content of the cell, it can lead to kidney failure. The control of bicarbonate ions also influences the water content in the eyes, and if the isozyme is not working properly, a buildup of fluid can lead to glaucoma.

Additional 250 words + 400 words/equivalents - Carbonic Anhydrase

Mammals breathe in oxygen and breathe out carbon dioxide. We’ve learned this over the many years of being in this world. However what we don’t know is that there is an enzyme in the red blood cells called carbonic anhydrase. Carbonic anhydrase helps to convert carbon dioxide and water into carbonic acid and bicarbonate ions. In our lungs, carbonic anhydrase does the opposite where it converts the carbonic acid back into carbon dioxide so we can breathe that out. The Bohr Effect occurs in the body where carbon dioxide and protons affect the affinity of hemoglobin for oxygen. The lungs are always trying to pump oxygen efficiently to the rest of the body and one of the ways it does this is by oxygen binding to hemoglobin and then being transported throughout the body. When carbon dioxide is on its way back the Haldane effect is seen where oxygen affects the affinity of hemoglobin for carbon dioxide and protons.

Carbonic anhydrase does a variety of things in our body such as controlling the blood pH level by maintaining the bicarbonate ions that get dissolved in our blood. It also controls the water retention in our kidneys and eyes. If carbonic anhydrase does not work properly, it can lead to kidney failure and glaucoma which can leave you blind. The enzyme also maintains the acidity levels in our stomach and maintains a neutral pH level in our saliva. If carbonic anhydrase does not work properly here, it could lead to ulcers.

Figure 1. Human backbone structure of the Carbonic Anhydrase II enzyme at 2.0 angstrom resolution. From PDB: 1CA2

Figure 2. Mechanism for carbonic anhydrase.

Zn²⁺ is the metal centre that is used in the carbonic anhydrase enzyme. The reason that Zn²⁺ is used instead of any other metal centre such as copper, nickel, cobalt or even iron is because of the fact that Zn²⁺ is a “hard” metal whereas these other metals are known as “intermediate” metals. Zn²⁺ also happens to be a stronger lewis acid and this is due to the fact that Zn²⁺ is in the first row and happens to be on the furthest right hand side in the periodic table and so this means that it is the most electronegative of the transition metals and it has a much greater electron withdrawing on the water ligand. Zn²⁺ is non redox active and coordinates well with histidine and cysteine ligands.

Figure 3. Image of human Carbonic Anhydrase II showing the ligand interactions and the zinc metal centre. Histidine, and threonine are able to be seen here.