Carbamino groups group

Unlike acetylcholine and methacholine, carbachol contains a carbamino functional group instead of an acetyl group, which is not responsive to hydrolysis by cholinesterase. In vitro studies have shown that the rate of hydrolysis is at least twice as slow as that of acetylcholine. 

C. Formation of carbamino groups In hemoglobin In ribulose bisphosphate carboxylase Eq. 7-23 Chapters 13,23... 

By elimination dissolved C02, bicarbonate, and carbamino groups are higher in venous blood, because C02 is being transported from the peripheral tissue to lungs via these vehicles. Venous blood, containing more deoxyhemoglobin than arterial blood, will have more T-forms. 

Although Hb can carry as many moles of CO2 as of O2, the HCO system is a more important way of transporting CO2. When the N-terminal amino groups are blocked by carbamylation with CNO , no marked degree of acidosis develops. The carbamino groups decrease the affinity of Hb for O2. The Pcoj thus can affect oxygen affinity independently of any effect it may have on pH and may... 

Bicarbonate acts not only as a blood buffer system, but also represents the main form in which CO2 is transported from respiring tissues to the lungs for expiration, Some CO2 is transported as carbamino groups of proteins Protein-NHj + COj Protein-NH-COOH Protein-NH-COO-+ H and about 80 % of CO2 is transported as bicarbonate. The different forms of blood CO2 are in equilibrium ... 

Carbamino group see Buffer, section on buffers of body fluids. 

This shift in the 02-binding properties of Hb is caused by the acidity (Fig. 8) and high CO2 tension (CO2 alone is effective at constant pH) in respiring tissue, and the low acidity and low CO2 tension in the lungs. The carbamino groups, formed by reaction of CO2 with the non-ionized terminal a-amino... 

Moreover, when carbamino and nitro groups are simultaneously in the ortho position to the triple bond, isomerization occurs only with participation of the amide group (Scheme 125). 

Carbon dioxide can combine chemically with the terminal amine groups (NH2) in blood proteins. The most important of these proteins for this process is hemoglobin. The combination of carbon dioxide and hemoglobin forms carbamino hemoglobin ... 

NAl/3 Val Val or Gly Ser Ac-Ala Ac-Ala In human and many other vertebrate deoxy-Hbs, the a-amino groups bind either organic phosphate or carbamino CO2, which in turn forms a salt bridge with Lys 82 of the same p chain in crocodile Hb, blocking of a-NHs or Pro in position 2 inhibits these functions... 

Binding of C02 Most of the carbon dioxide produced in metabolism is hydrated and transported as bicarbonate ion (see p. 9). However, some CO2 is carried as carbamate bound to the uncharged a-amino groups of hemoglobin (carbamino-hemo-globin see Figure 3.7), which can be represented schematically as follows ... 

Total carbon dioxide (CO2) content of plasma consists of carbon dioxide dissolved in an aqueous solution (dCOa), CO2 loosely bound to amine groups in proteins (carbamino compounds), HCO3 and vanishingly small amounts of CO ions, and carbonic acid (H2CO3). Bicarbonate ions make up ail but 2 mmol/L of the total carbon dioxide of plasma (22 to 31 mmol/L). Measurement of the tota CO2 as part of an electrolyte profile is useful chiefly to evaluate HCO3 concentration in assessment of acid-base disorders. 

Figure 46-7 Reactions of CO2 with water and amino groups. Hydrogen bonding is indicated by a dotted bond.The carbamino acid is fairly strong —R—NH—COOH + R—NH—...

About 20 percent of the CO2 in blood is carried as carbamino compounds formed by the reaction with amino groups of hemoglobin. The reaction may be represented as... 

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