N-terminal portion acts as an initiator of the inactivation of pepsin at
... molecule is identical to pepsinogen, minor differences may be responsible for pepsin’s instability at neutral pHs. The most obvious differences between pepsin and pepsinogen are found in the prosegment portion. Not only does the prosegment cover the active site cleft, but it contains a large number ...
... molecule is identical to pepsinogen, minor differences may be responsible for pepsin’s instability at neutral pHs. The most obvious differences between pepsin and pepsinogen are found in the prosegment portion. Not only does the prosegment cover the active site cleft, but it contains a large number ...
Chapter 8
... The reaction is initiated by removal of the proR proton of the proR acetate. The reaction proceeds by labilization of the hydroxyl function due to withdrawal of the proton by the base followed by capture of the hydroxide by a Lewis acid. Thus the citrate is dehydrated, the double bond is introduced ...
... The reaction is initiated by removal of the proR proton of the proR acetate. The reaction proceeds by labilization of the hydroxyl function due to withdrawal of the proton by the base followed by capture of the hydroxide by a Lewis acid. Thus the citrate is dehydrated, the double bond is introduced ...
Introduction to Carbohydrates
... Liver mitochondria can convert acetyl CoA derived from fatty acid oxidation into the ketone bodies, acetoacetate and 3hydroxybutyrate. Peripheral tissues possessing mitochondria can oxidize 3hydroxybutyrate to acetoacetate, which can be reconverted to acetyl CoA, thus producing energy for the ce ...
... Liver mitochondria can convert acetyl CoA derived from fatty acid oxidation into the ketone bodies, acetoacetate and 3hydroxybutyrate. Peripheral tissues possessing mitochondria can oxidize 3hydroxybutyrate to acetoacetate, which can be reconverted to acetyl CoA, thus producing energy for the ce ...
A 5000-Fold Increase in the Specificity of a Bacterial
... Phosphotriesterases (PTEs) have been isolated from a range of bacterial species, including Agrobcaterium radiobacter (PTEAr), and are efficient enzymes with broad substrate ranges. The turnover rate of PTEAr for the common organophosphorous insecticide malathion is lower than expected based on its p ...
... Phosphotriesterases (PTEs) have been isolated from a range of bacterial species, including Agrobcaterium radiobacter (PTEAr), and are efficient enzymes with broad substrate ranges. The turnover rate of PTEAr for the common organophosphorous insecticide malathion is lower than expected based on its p ...
1. Fatty acids may be synthesized from dietary glucose via pyruvate
... a. Reaction. Butyryl-ACP (a four-carbon unit) reacts with another malonyl group via the reactions described above to form a six-carbon unit, and the reactions of the fatty acid synthase complex continue. b. Reaction repeats. After seven turns of this cycle, palmitic-ACP (a 16-carbon unit) is synthes ...
... a. Reaction. Butyryl-ACP (a four-carbon unit) reacts with another malonyl group via the reactions described above to form a six-carbon unit, and the reactions of the fatty acid synthase complex continue. b. Reaction repeats. After seven turns of this cycle, palmitic-ACP (a 16-carbon unit) is synthes ...
Formatted - RESPIRATION
... This reaction is considered to be the committed reaction of glycolysis as this conversion is irreversible. Conversion of fructose-1,6-diphosphate into fructose-6-phosphate requires a different enzyme, phosphatase. Moreover, once fructose-1,6-diphosphate is formed, it is destined to be used further i ...
... This reaction is considered to be the committed reaction of glycolysis as this conversion is irreversible. Conversion of fructose-1,6-diphosphate into fructose-6-phosphate requires a different enzyme, phosphatase. Moreover, once fructose-1,6-diphosphate is formed, it is destined to be used further i ...
Enzymologychapter13 - Panama College of Cell Science
... Many enzymes carry out their catalytic function relying solely on their protein structure. Many others require nonprotein components, called cofactors (Table 13.2). Cofactors may be metal ions or organic molecules referred to as coenzymes. Coenzymes and cofactors provide proteins with chemically ver ...
... Many enzymes carry out their catalytic function relying solely on their protein structure. Many others require nonprotein components, called cofactors (Table 13.2). Cofactors may be metal ions or organic molecules referred to as coenzymes. Coenzymes and cofactors provide proteins with chemically ver ...
The Enolase Superfamily: A General Strategy for Enzyme
... Abstract published in AdVance ACS Abstracts, November 1, 1996. ...
... Abstract published in AdVance ACS Abstracts, November 1, 1996. ...
Enzymes:The Catalysts of Life I
... Molecules that could react with one another often do not because they lack sufficient energy. For every reaction, there is a specific activation energy (EA), which is the minimum amount of energy that reactants must have before collisions between them will be successful in giving rise to products. M ...
... Molecules that could react with one another often do not because they lack sufficient energy. For every reaction, there is a specific activation energy (EA), which is the minimum amount of energy that reactants must have before collisions between them will be successful in giving rise to products. M ...
18. enzymes iii
... ∆G°′ for the reaction is negative and the equilibrium favours P. This equilibrium is not affected by any catalyst. A favourable equilibrium, however, does not mean that S → P conversion is fast. The rate of a reaction, in fact, depends on an entirely different parameter. There exists an energetic ba ...
... ∆G°′ for the reaction is negative and the equilibrium favours P. This equilibrium is not affected by any catalyst. A favourable equilibrium, however, does not mean that S → P conversion is fast. The rate of a reaction, in fact, depends on an entirely different parameter. There exists an energetic ba ...
Enzymes
... rates. The function of a catalyst is to increase the rate of a reaction. Catalysts do not affect reaction equilibria. Any reaction, such as S 4 3 P, can be described by a reaction coordinate diagram (Fig. 8–2), a picture of the energy changes during the reaction. As we noted in Chapters 1 and 3, ene ...
... rates. The function of a catalyst is to increase the rate of a reaction. Catalysts do not affect reaction equilibria. Any reaction, such as S 4 3 P, can be described by a reaction coordinate diagram (Fig. 8–2), a picture of the energy changes during the reaction. As we noted in Chapters 1 and 3, ene ...
Studies Into the Allosteric Regulation of ADP
... in plants, cyanobacteria, and archae. Glycogen and starch are similar in composition. They are both polymers primarily composed of glucose moieties linked together by α-1,4 linkages (Figure 1), but they each have some distinct physical and chemical properties.4 In glycogen, chains of α-1,4-polygluca ...
... in plants, cyanobacteria, and archae. Glycogen and starch are similar in composition. They are both polymers primarily composed of glucose moieties linked together by α-1,4 linkages (Figure 1), but they each have some distinct physical and chemical properties.4 In glycogen, chains of α-1,4-polygluca ...
Energy and Muscle Contraction
... Therefore, during this time, cellular respiration will be going at capacity, limited only by oxygen restraints. Glycolysis, on the other hand, will proceed at an accelerated rate for the purpose of gaining extra ATP. Note that during this time, pyruvate will be fed into the mitochondria as fast as s ...
... Therefore, during this time, cellular respiration will be going at capacity, limited only by oxygen restraints. Glycolysis, on the other hand, will proceed at an accelerated rate for the purpose of gaining extra ATP. Note that during this time, pyruvate will be fed into the mitochondria as fast as s ...
WRL3116.tmp
... 54. The result of a(n) __________ reaction is that energy is released. Energy must be added for a(n) __________ reaction to proceed. A. Enzyme catalyzed, non-spontaneous B. * Exergonic, endergonic C. Endergonic, spontaneous D. Catalytic, non-catalytic E. Oxidative, hydrolysis 55. The steady state as ...
... 54. The result of a(n) __________ reaction is that energy is released. Energy must be added for a(n) __________ reaction to proceed. A. Enzyme catalyzed, non-spontaneous B. * Exergonic, endergonic C. Endergonic, spontaneous D. Catalytic, non-catalytic E. Oxidative, hydrolysis 55. The steady state as ...
Fatty Acids :biosynthesis
... Double Bonds in Odd-Numbered Positions • As acetyl CoA’s are removed from an unsaturated fatty acid, double bonds move into or near the active sites of the oxidation cycle enzymes. • An odd-numbered double bond moves into the 3-position, which is not a substrate for the principal enzymes of the cy ...
... Double Bonds in Odd-Numbered Positions • As acetyl CoA’s are removed from an unsaturated fatty acid, double bonds move into or near the active sites of the oxidation cycle enzymes. • An odd-numbered double bond moves into the 3-position, which is not a substrate for the principal enzymes of the cy ...
06_Metabolism of lipid
... Transport of Fatty Acids and Glycerol • Fatty acids and glycerol diffuse through the adipocyte membrane and enter bloodstream. • Glycerol is transported via the blood in free state and oxidized or converted to glucose in liver. • Fatty acids are traveled bound to albumin. • In heart, skeletal muscl ...
... Transport of Fatty Acids and Glycerol • Fatty acids and glycerol diffuse through the adipocyte membrane and enter bloodstream. • Glycerol is transported via the blood in free state and oxidized or converted to glucose in liver. • Fatty acids are traveled bound to albumin. • In heart, skeletal muscl ...
Aminolaevulinic acid synthase of Rhodobacter capsulatus: high
... the internal aldimine in a transaldimination reaction is common to both pathways [9,23]. The existence of the α-amino-β-oxoadipate intermediate has not been experimentally confirmed for ALAS catalysis as yet, but it is known that the corresponding intermediates occur in AONS reactions [21]. The enzy ...
... the internal aldimine in a transaldimination reaction is common to both pathways [9,23]. The existence of the α-amino-β-oxoadipate intermediate has not been experimentally confirmed for ALAS catalysis as yet, but it is known that the corresponding intermediates occur in AONS reactions [21]. The enzy ...
Fat Metabolism
... Diabetes and Ketone Bodies • When there is not enough insulin in the blood and it must break down fat for its energy. • Ketones build up in the blood and then spill over into the urine so that the body can get rid of them. Acetone can be exhaled through the lungs. This gives the breath a fruity odo ...
... Diabetes and Ketone Bodies • When there is not enough insulin in the blood and it must break down fat for its energy. • Ketones build up in the blood and then spill over into the urine so that the body can get rid of them. Acetone can be exhaled through the lungs. This gives the breath a fruity odo ...
lecture6
... rearrangement thatrequires vitamin B12 (also known as cobalamin). Propionyl CoA is carboxylated at the expense of the hydrolysis of an ATP to yield the d isomer of methylmalonyl CoA (Figure 22.11). This carboxylation reaction is catalyzed by propionyl CoA carboxylase, a biotin enzyme that is homolog ...
... rearrangement thatrequires vitamin B12 (also known as cobalamin). Propionyl CoA is carboxylated at the expense of the hydrolysis of an ATP to yield the d isomer of methylmalonyl CoA (Figure 22.11). This carboxylation reaction is catalyzed by propionyl CoA carboxylase, a biotin enzyme that is homolog ...
Stereochemistry and Mechanism of Reactions Catalyzed by
... substrate amino acid and the cofactor to an enzyme-bound Schiff s base between pyridoxal phosphate and cr-aminoacrylic acid as a universal intermediate. This intermediate can follow various reaction paths, giving the different observed products. In this paper we report results which clarify various ...
... substrate amino acid and the cofactor to an enzyme-bound Schiff s base between pyridoxal phosphate and cr-aminoacrylic acid as a universal intermediate. This intermediate can follow various reaction paths, giving the different observed products. In this paper we report results which clarify various ...
lecture6
... Propionyl CoA Is Converted into Succinyl CoA in a Reaction That RequiresVitamin B12 The pathway from propionyl CoA to succinyl CoA is especially interesting because it entails a rearrangement thatrequires vitamin B12 (also known as cobalamin). Propionyl CoA is carboxylated at the expense of the hydr ...
... Propionyl CoA Is Converted into Succinyl CoA in a Reaction That RequiresVitamin B12 The pathway from propionyl CoA to succinyl CoA is especially interesting because it entails a rearrangement thatrequires vitamin B12 (also known as cobalamin). Propionyl CoA is carboxylated at the expense of the hydr ...
The Complete Oxidation of Palmitate Yields 106 Molecules of ATP
... rearrangement thatrequires vitamin B12 (also known as cobalamin). Propionyl CoA is carboxylated at the expense of the hydrolysis of an ATP to yield the d isomer of methylmalonyl CoA (Figure 22.11). This carboxylation reaction is catalyzed by propionyl CoA carboxylase, a biotin enzyme that is homolog ...
... rearrangement thatrequires vitamin B12 (also known as cobalamin). Propionyl CoA is carboxylated at the expense of the hydrolysis of an ATP to yield the d isomer of methylmalonyl CoA (Figure 22.11). This carboxylation reaction is catalyzed by propionyl CoA carboxylase, a biotin enzyme that is homolog ...
Multiple Sequence Motifs in the Rubisco Small
... N-terminal targeting signal, a transit peptide (TP), of 50 to 70 amino acid residues (Jarvis, 2008; Lee et al., 2008). However, recently, some plastid interior proteins have been identified that do not have the N-terminal canonical TP (Miras et al., 2002, 2007; Nada and Soll, 2004). The long TP cons ...
... N-terminal targeting signal, a transit peptide (TP), of 50 to 70 amino acid residues (Jarvis, 2008; Lee et al., 2008). However, recently, some plastid interior proteins have been identified that do not have the N-terminal canonical TP (Miras et al., 2002, 2007; Nada and Soll, 2004). The long TP cons ...
AMP-activated protein kinase phosphorylates transcription factors of
... doi:10.1152/japplphysiol.00900.2007.—AMP-activated protein kinase (AMPK) has been identified as a regulator of gene transcription, increasing mitochondrial proteins of oxidative metabolism as well as hexokinase expression in skeletal muscle. In mice, musclespecific knockout of LKB1, a component of t ...
... doi:10.1152/japplphysiol.00900.2007.—AMP-activated protein kinase (AMPK) has been identified as a regulator of gene transcription, increasing mitochondrial proteins of oxidative metabolism as well as hexokinase expression in skeletal muscle. In mice, musclespecific knockout of LKB1, a component of t ...
Principles of BIOCHEMISTRY
... The entry of acetyl CoA into the citric acid cycle depends on the availability of oxaloacetate. The concentration of oxaloacetate is lowered if carbohydrate is unavailable (starvation) or improperly utilized (diabetes). Oxaloacetate is normally formed from pyruvate by pyruvate carboxylase (anaplerot ...
... The entry of acetyl CoA into the citric acid cycle depends on the availability of oxaloacetate. The concentration of oxaloacetate is lowered if carbohydrate is unavailable (starvation) or improperly utilized (diabetes). Oxaloacetate is normally formed from pyruvate by pyruvate carboxylase (anaplerot ...
Luciferase
Luciferase is a generic term for the class of oxidative enzymes used in bioluminescence and is distinct from a photoprotein. The name is derived from Lucifer, the root of which means 'light-bearer' (lucem ferre). One example is the firefly luciferase (EC 1.13.12.7) from the firefly Photinus pyralis. ""Firefly luciferase"" as a laboratory reagent often refers to P. pyralis luciferase although recombinant luciferases from several other species of fireflies are also commercially available.