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Basic Concepts of Acid–Base Physiology
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The formation of carbamino compounds can account for about 15% of the total CO2 in blood. In fact, 1 g of haemoglobin has three times the buffering capacity of 1 g of plasma proteins. As the concentration of haemoglobin is approximately twice that of plasma proteins, haemoglobin has six times the capacity of plasma proteins to buffer H+ ions.
Acid–base physiology
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2015
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The formation of carbamino compounds can account for about 15% of the total CO2 in blood. In fact, 1 g of haemoglobin has three times the buffering capacity of 1 g of plasma proteins. As the concentration of haemoglobin is approximately twice that of plasma proteins, haemoglobin has six times the capacity of plasma proteins to buffer H+ ions.
Paper 3 Answers
Published in James Day, Amy Thomson, Tamsin McAllister, Nawal Bahal, Get Through, 2014
James Day, Amy Thomson, Tamsin McAllister, Nawal Bahal
Carbon dioxide (CO2) is a product of cellular metabolism (200 ml·min−1 at rest) and is excreted via the lungs. Transport of carbon dioxide to the lungs occurs in the blood in three ways: Dissolved: 5% of carbon dioxide in arterial and 10% in venous blood. CO2 is 20 times more soluble than oxygen and has a solubility coefficient of 0.231 mmol·litre−1·kPa−1 at 37°C.Bound to proteins: predominantly haemoglobin. CO2 rapidly combines with terminal uncharged amino groups to form carbamino compounds. In the case of haemoglobin, carbaminohaemoglobin compounds are effective hydrogen ion buffers. This is the method of transport of 6% of CO2 in arterial blood and 30% in venous blood.As carbonic acid: this is the predominant mechanism of CO2 transport, comprising 90% of CO2 in arterial blood and 60% in venous blood. Red blood cell carbonic anhydrase catalyzes the reaction of carbon dioxide with water to form carbonic acid, which then freely dissociates to hydrogen ions and bicarbonate. Bicarbonate then diffuses out of the red blood cell in exchange for chloride ions, known as the Hamburger effect.
Proteomic profiling of carbonic anhydrase CA3 in skeletal muscle
Published in Expert Review of Proteomics, 2021
Paul Dowling, Stephen Gargan, Margit Zweyer, Hemmen Sabir, Dieter Swandulla, Kay Ohlendieck
Carbon dioxide is an abundant by-product of cellular metabolism and requires efficient removal to prevent hypercapnia-associated cellular impairments and acid–base imbalance [1–3]. The swift elimination of carbon dioxide involves its transportation in the blood in its dissolved form and as bicarbonate ions, as well as in the form of carbamino-hemoglobin [4]. A scientific breakthrough in our understanding of how enzymatic activity is involved in this key process of metabolic homeostasis was the discovery of the enzyme carbonic anhydrase (CA) in erythrocytes [5]. This abundant enzyme reversibly catalyzes the continuous conversion of carbon dioxide and water into the dissociated ions of carbonic acid, i.e. bicarbonate and protons. Carbonic anhydrases, also named carbonate dehydratases (EC 4.2.1.1), belong to the class of lyases and the identification and characterization of diverse types of CAs led to the discovery of 8 distinct families, i.e. α, β, γ, δ, ζ, η, θ, ι genes that encode these enzymes [6–8] whereby various metals act as physiologically relevant cofactors of CAs [9]. Since these groups of proteins do not exhibit significant similarities in their amino acid sequence, they were probably generated by divergent evolutionary mechanisms. The α-family of CAs is present in mammals and consists of 16 isoforms with a broad tissue distribution pattern [10].