CITRIC ACID/KREB's CYCLE: Process and Explanation
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Spectroscopy of Porphyrins
BORIS F. KIM and JOSEPH BOHANDY SPECTROSCOPY OF PORPHYRINS Porphyrins are an important class of compounds that are of interest in molecular biology because of the important roles they play in vital biochemical systems such as biochemical energy conversion in animals, oxygen transport in blood, and photosynthetic energy conversion in plants. We are studying the physical properties of the energy states of porphyrins using the techniques of ex perimental and theoretical spectroscopy with the aim of contributing to a basic understanding of their biochemical behavior. INTRODUCTION Metalloporphin Porphyrins are a class of complex organic chemical compounds found in such diverse places as crude oil, plants, and human beings. They are, in most cases, tailored to carry out vital chemical transformations in intricate biochemical or biophysical systems. They are the key constituents of chlorophyll in plants and of hemoglobin in animals. Without them, life would y be impossible. t Free base porphin These molecules display a wide range of chemical and physical properties that depend on the structural details of the particular porphyrin molecule. All por ~x phyrins are vividly colored and absorb light in the visible and ultraviolet regions of the spectrum. Some exhibit luminescence, paramagnetism, photoconduc tion, or semiconduction. Spme are photosensitizers Wavelength (nanometers) or catalysts. Scientists from several disciplines have been interested in unraveling the principles that cause Fig. 1-The chemical structures for the two forms of por· this diversity of properties. phin are shown on the left. A carbon atom and a hydrogen The simplest compound of all porphyrins is por atom are understood to be at each apex not attached to a nitrogen atom. -
Electronic Spectroscopy of Free Base Porphyrins and Metalloporphyrins
Absorption and Fluorescence Spectroscopy of Tetraphenylporphyrin§ and Metallo-Tetraphenylporphyrin Introduction The word porphyrin is derived from the Greek porphura meaning purple, and all porphyrins are intensely coloured1. Porphyrins comprise an important class of molecules that serve nature in a variety of ways. The Metalloporphyrin ring is found in a variety of important biological system where it is the active component of the system or in some ways intimately connected with the activity of the system. Many of these porphyrins synthesized are the basic structure of biological porphyrins which are the active sites of numerous proteins, whose functions range from oxygen transfer and storage (hemoglobin and myoglobin) to electron transfer (cytochrome c, cytochrome oxidase) to energy conversion (chlorophyll). They also have been proven to be efficient sensitizers and catalyst in a number of chemical and photochemical processes especially photodynamic therapy (PDT). The diversity of their functions is due in part to the variety of metals that bind in the “pocket” of the porphyrin ring system (Fig. 1). Figure 1. Metallated Tetraphenylporphyrin Upon metalation the porphyrin ring system deprotonates, forming a dianionic ligand (Fig. 2). The metal ions behave as Lewis acids, accepting lone pairs of electrons ________________________________ § We all need to thank Jay Stephens for synthesizing the H2TPP 2 from the dianionic porphyrin ligand. Unlike most transition metal complexes, their color is due to absorption(s) within the porphyrin ligand involving the excitation of electrons from π to π* porphyrin ring orbitals. Figure 2. Synthesis of Zn(TPP) The electronic absorption spectrum of a typical porphyrin consists of a strong transition to the second excited state (S0 S2) at about 400 nm (the Soret or B band) and a weak transition to the first excited state (S0 S1) at about 550 nm (the Q band). -
Detection and Formation Scenario of Citric Acid, Pyruvic Acid, and Other Possible Metabolism Precursors in Carbonaceous Meteorites
Detection and formation scenario of citric acid, pyruvic acid, and other possible metabolism precursors in carbonaceous meteorites George Coopera,1, Chris Reeda, Dang Nguyena, Malika Cartera, and Yi Wangb aExobiology Branch, Space Science Division, National Aeronautics and Space Administration-Ames Research Center, Moffett Field, CA 94035; and bDevelopment, Planning, Research, and Analysis/ZymaX Forensics Isotope, 600 South Andreasen Drive, Suite B, Escondido, CA 92029 Edited by David Deamer, University of California, Santa Cruz, CA, and accepted by the Editorial Board July 1, 2011 (received for review April 12, 2011) Carbonaceous meteorites deliver a variety of organic compounds chained three-carbon (3C) pyruvic acid through the eight-carbon to Earth that may have played a role in the origin and/or evolution (8C) 7-oxooctanoic acid and the branched 6C acid, 3-methyl- of biochemical pathways. Some apparently ancient and critical 4-oxopentanoic acid (β-methyl levulinic acid), Fig. 1, Table S1. metabolic processes require several compounds, some of which 2-methyl-4-oxopenanoic acid (α-methyl levulinic acid) is tenta- are relatively labile such as keto acids. Therefore, a prebiotic setting tively identified (i.e., identified by mass spectral interpretation for any such individual process would have required either a only). As a group, these keto acids are relatively unusual in that continuous distant source for the entire suite of intact precursor the ketone carbon is located in a terminal-acetyl group rather molecules and/or an energetic and compact local synthesis, parti- than at the second carbon as in most of the more biologically cularly of the more fragile members. -
Bacterial Metabolism of Glycine and Alanine David Paretsky Iowa State College
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1948 Bacterial metabolism of glycine and alanine David Paretsky Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Biochemistry Commons, and the Microbiology Commons Recommended Citation Paretsky, David, "Bacterial metabolism of glycine and alanine " (1948). Retrospective Theses and Dissertations. 13762. https://lib.dr.iastate.edu/rtd/13762 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. NOTE TO USERS This reproduction is the best copy available. UMI BAG1ERIAL METABOLISM OP GL^CIKE AND ALANINE by David Paretsky A Itieais Submitted to the Graduate Faculty for the Degree of DOCTOR OP PHILOSOPHY Major Subjects physiological Bacteriology Approved? Signature was redacted for privacy. In Charge of Major Work Signature was redacted for privacy. Heaa'of' "la'jo'r 'Departn^en t Signature was redacted for privacy. Dean or Graduate -Golleg^ Iowa State College 1948 UMI Number: DP12896 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. -
Cellular Respiration Process by Which Cells Transfer Energy from Food To
Cellular Respiration Process by which cells transfer energy from food to ATP Cells rely heavily on Oxygen Can be Aerobic or Anaerobic Brain cells cannot produce energy anaerobicly Heart Cells have a minimal ability to produce energy anaerobicly Glycolysis, Krebs cycle, Electron Transport Carb Metabolism Only food the can create energy through Anaerobic metabolism Preferred food of the body, uses least amount of oxygen Glucose- 6-carbon sugar C6H12O6 Break down= Glucose + Oxygen = Water + Carbon Dioxide + Energy Excess Glucose stored as Glycogen stored in the liver & muscles Stage 1- Glycolysis Prepares glucose to enter the next stage Converts Glucose to Pyruvic Acid (Aerobic) or Lactic Acid (Anaerobic) ATP is produced 2 ATP used in the first steps (Only 1 if glycogen) 2 ATP produced end steps 2 NAD FAD & NAD similar to a taxi (Transport Oxygen) 6 Carbon Glucose broken down to 2 3-carbon cells Lactic Acid- Glycogen (Anaerobic) Pyruvic acid- Glucose (Aerobic) Stage 2- Formation of Acetyl Coenzyme A Converts Pyruvate to Acetyl Coenzyme A No ATP is used or produced 2 NAD (4 NAD) Stage 3- Krebs Cycle Begins & ends with the same substance No ATP is used 2 ATP Made (2 Cells) Hydrogen’s spilt for Electron Transport 6 NAD Stage 4- Electron Transport System Hydrogen taken from FAD & NAD to make water Electrons are dropped off and then pick up- repeats 3 times One ATP for each for each pair of Hydrogen’s Each NAD makes 3ATP Each FAD makes 2 ATP Total Stage 1 – Glycolysis-2 ATP, NAD but can’t be used in skeletal muscle (FAD uses electron in skeletal -
Tricarboxylic Acid (TCA) Cycle Intermediates: Regulators of Immune Responses
life Review Tricarboxylic Acid (TCA) Cycle Intermediates: Regulators of Immune Responses Inseok Choi , Hyewon Son and Jea-Hyun Baek * School of Life Science, Handong Global University, Pohang, Gyeongbuk 37554, Korea; [email protected] (I.C.); [email protected] (H.S.) * Correspondence: [email protected]; Tel.: +82-54-260-1347 Abstract: The tricarboxylic acid cycle (TCA) is a series of chemical reactions used in aerobic organisms to generate energy via the oxidation of acetylcoenzyme A (CoA) derived from carbohydrates, fatty acids and proteins. In the eukaryotic system, the TCA cycle occurs completely in mitochondria, while the intermediates of the TCA cycle are retained inside mitochondria due to their polarity and hydrophilicity. Under cell stress conditions, mitochondria can become disrupted and release their contents, which act as danger signals in the cytosol. Of note, the TCA cycle intermediates may also leak from dysfunctioning mitochondria and regulate cellular processes. Increasing evidence shows that the metabolites of the TCA cycle are substantially involved in the regulation of immune responses. In this review, we aimed to provide a comprehensive systematic overview of the molecular mechanisms of each TCA cycle intermediate that may play key roles in regulating cellular immunity in cell stress and discuss its implication for immune activation and suppression. Keywords: Krebs cycle; tricarboxylic acid cycle; cellular immunity; immunometabolism 1. Introduction The tricarboxylic acid cycle (TCA, also known as the Krebs cycle or the citric acid Citation: Choi, I.; Son, H.; Baek, J.-H. Tricarboxylic Acid (TCA) Cycle cycle) is a series of chemical reactions used in aerobic organisms (pro- and eukaryotes) to Intermediates: Regulators of Immune generate energy via the oxidation of acetyl-coenzyme A (CoA) derived from carbohydrates, Responses. -
"Changes in Pyruvic Acid Content and GPT Activity in Chilling-Sensitive
HORTSCIENCE 25(8):952-953. 1990. into -80C methanol (mixture of solid CO2 and methanol); the acid was then extracted with 0.6 M HPO3 at 0C. After adding 2,4- Changes in Pyruvic Acid Content and dinitrophenylhydrazine to the extraction, the mixture was allowed to stand for 3 hr at room GPT Activity in Chilling-sensitive and temperature in darkness. Finally, the hydra- zone produced was dissolved in 2 ml of ab- Nonsensitive Crops solute methanol. To separate and quantify the pyruvic acid in the keto acids, a 10-µl Hironobu Tsuchida and Cheng Dan-Hong aliquot of the solution was directly subjected Faculty of Agriculture, Kobe University, Rokkodai-cho, Nadaku, Kobe, to high-performance liquid chromatography Japan (HPLC) . A Gaskuro Kogyo (Tokyo) liquid chro- Kazuko Inoue matograph (Model-570B) equipped with a sampling valve with a 20-µl loop (Rheodyne Consumer Economic Research Institute, 6-28, 1-cho, Nakatsu, Model 7120) was used. The chromato- Ooyodo-ku, Osaka, Japan graphic column (4.0 i-d. × 250 mm) was of stainless steel and packed with Unicil Q- Nobuyuki Kozukue 30 (particle diameter 5 µm, Gaskuro Kog- Department of Home Economics, Kenmei Junior College, 68-Honmachi, yo). The UV detector was set-at 254 nm. A Himeji City, Japan mobile phase [50 chloroform : 5 n-butanol : 5 acetic acid : 50 water (by volume)] was Susumu Mizuno pumped through the column at a flow rate of 1 ml·min-1. The chart speed was adjusted Faculty of Agriculture, Kobe University, Rokkodai-cho, Nadaku, Kobe, -1 to 5 mm·min . Analytical-grade sodium Japan pyruvate was purchased from Wako Pure Additional index words. -
Citric Acid Cycle
CHEM464 / Medh, J.D. The Citric Acid Cycle Citric Acid Cycle: Central Role in Catabolism • Stage II of catabolism involves the conversion of carbohydrates, fats and aminoacids into acetylCoA • In aerobic organisms, citric acid cycle makes up the final stage of catabolism when acetyl CoA is completely oxidized to CO2. • Also called Krebs cycle or tricarboxylic acid (TCA) cycle. • It is a central integrative pathway that harvests chemical energy from biological fuel in the form of electrons in NADH and FADH2 (oxidation is loss of electrons). • NADH and FADH2 transfer electrons via the electron transport chain to final electron acceptor, O2, to form H2O. Entry of Pyruvate into the TCA cycle • Pyruvate is formed in the cytosol as a product of glycolysis • For entry into the TCA cycle, it has to be converted to Acetyl CoA. • Oxidation of pyruvate to acetyl CoA is catalyzed by the pyruvate dehydrogenase complex in the mitochondria • Mitochondria consist of inner and outer membranes and the matrix • Enzymes of the PDH complex and the TCA cycle (except succinate dehydrogenase) are in the matrix • Pyruvate translocase is an antiporter present in the inner mitochondrial membrane that allows entry of a molecule of pyruvate in exchange for a hydroxide ion. 1 CHEM464 / Medh, J.D. The Citric Acid Cycle The Pyruvate Dehydrogenase (PDH) complex • The PDH complex consists of 3 enzymes. They are: pyruvate dehydrogenase (E1), Dihydrolipoyl transacetylase (E2) and dihydrolipoyl dehydrogenase (E3). • It has 5 cofactors: CoASH, NAD+, lipoamide, TPP and FAD. CoASH and NAD+ participate stoichiometrically in the reaction, the other 3 cofactors have catalytic functions. -
Pyruvic Acid
FT-N12450 Pyruvic acid Product Information Chemical name: Pyruvic acid, Sodium salt Other names: 2-oxopropanoic acid , α-ketopropionic acid, acetylformic acid, pyroracemic acid, Pyr Cat.# : N12450, 100 g N12451,250 g N12452, 1Kg Larger quantities: inquire Structure: CH3COCO2Na CAS: 127-17-3 Molecular Weight: 110.05 Storage: Room temperature, protected from moisture Safety: EU classification: Highly toxic (T+) ; Dangerous for the environment (N) R-phrases: R21, R26, R28, R32, R50, R53 S-Phrases: S1, S2, S28, S45, S60, S61 Test Specification/ Spécification Appearance: white white crystalline powder Solubility: In water (20%) Clear, colorless Purity: >99% Loss on drying: <0.5% Melting point: >320°C Contact your local distributor Uptima, powered by [email protected] P.1 FT-N12450 Physical datas Pyruvic acid is a colorless liquid with a smell similar to acetic acid. It is miscible with water, and soluble in ethanol and diethyl ether. Cell Biology role Pyruvate is an important chemical compound in biochemistry. It is even is suspected of providing the fertile basis for the formation of life.. Pyruvate is the output of the metabolism of glucose known as glycolysis. One molecule of glucose breaks down into two molecules of pyruvic acid, which are then used to provide further energy, in one of two ways. Provided that sufficient oxygen is available, pyruvic acid is converted into acetyl- coenzyme A, which is the main input for a series of reactions known as the Krebs cycle. Pyruvate is also converted to oxaloacetate by an anaplerotic reaction and then further broken down to carbon dioxide. The cycle is also called the citric acid cycle, because citric acid is one of the intermediate compounds formed during the reactions. -
The Role of Some of the Krebs Cycle Reactions in the Biosynthetic Functions of Thiobacillus Thioparus
AN ABSTRACT OF THE THESIS OF Gerald G. Still for the PhD in Chemistry (Name) (Degree) (Major) Date thesis is presented May 14, 1965 Title THE ROLE OF SOME OF THE KREBS CYCLE REACTIONS IN THE BIOSYNTHETIC FUNCTIONS OF THIOBACILLUS THIOPARUS Abstract approved Redacted for Privacy (Major professor) Aseptic radiorespirometry has been used to examine the utilization of external carbon sources by proliferat- ing Thiobacillus thioparus cells. These studies reveal that glucose, galactose, mannose, fructose, ribose, DL- glutamate, and L- aspartate were not utilized by this chemoautotrophic organism. However, it has been shown that trace amounts of acetate, glycine, DL- serine, DL- alanine, succinate and fumarate can be utilized by T. thioparus cells. To elucidate the nature of the biosynthetic pathways operative in this bacteria, proliferating cell cultures were allowed to metabolize specifically 14C labeled substrates. The resulting 14C labeled cells were sub- sequently hydrolyzed, their amino acids isolated and subjected to degradation experiments. Examination of the respective fates of the label in DL- alanine- 2 -14C, acetate- 1 -14C, or acetate -2 -14C in the cellular metabolism revealed that the Krebs Cycle path- way is not functioning as a respiratory mechanism in T. thioparus. However, most of the reactions of the Krebs Cycle pathway are involved in the biosynthesis of carbon skeletons for various amino acids. A CO2 fixa- tion pathway of the C3 +C1 type is instrumental in provid- ing C4 dicarboxylic acids and those amino acids derived therefrom. Acetate can be incorporated into a -keto- glutarate and those amino acids derived therefrom, but cannot be incorporated into the C4 dicarboxylic acids. -
Transamination in Tumors, Fetal Tissues, and Regenerating Liver* Philip P
Transamination in Tumors, Fetal Tissues, and Regenerating Liver* Philip P. Cohen, M.D., and G. Leverne Hekhuis (From the Laboratory o~ Physiological Chemistry, Yale University School of Medicine, New Haven, Connecticut) (Received for publication June 9, I94I) von Euler and co-workers (22), on the basis of TISSUE SOURCES results of essentially qualitative experiments, first re- Tumors.--The mouse tumors employed in this in- ported that the transaminase activity ot~ tumors was vestigation were the following: low. These investigators, using Jensen sarcoma and normal muscle, measured the rate of disappearance of I. United States Public Health Service No. ~7-- oxaloacetic acid in the following reaction: originally described as a neuroepithelioma (20). 1 2. Sarcoma 37 .1 3. Yale No. xuan estrogen-induced ,) 1( + )-glutamic acid + oxaloacetic acid a mammary adenocarcinoma (5). 1 4. No. x5o9I-A - ~'b a-ketoglutaric acid + aspartic acid spontaneous mammary medullary adenocarcinoma In addition to studies of reaction I in tumors, Braun- (6) "1 5- No. 42--glioblastoma multiforme. 2 6. No. stein and Azarkh (2) studied the reaction: i o8--rhabdomyosarcoma. 2 The tumors were transplanted at regular intervals 2) glutamic acid+a-keto acid to insure a uniform supply. a-ketoglutaric acid + amino acid "-b- Fetal, kitten, and adult cat tissues.--Two pregnant cats provided the fetal tissue. The length of the preg- The amino acids investigated in the case of reaction nancy was uncertain, but was estimated to be in the 2b were the d- and l-forms of alanine, valine, leucine, last trimester in both instances. Hemihysterectomies and isoleucine. The rate of reaction za in which both were performed under nembutal anesthesia and 2 d(--)- and l(+)-glutamic acid were used, plus fetuses removed from each animal. -
Cellular Respiration Liberation of Energy by Oxidation of Food
Cellular Respiration Liberation of Energy by Oxidation of Food Respiration and Photosynthesis: Photosynthesis uses CO2 and H2O molecules to form C6H12O6 (glucose) and O2. Respiration is just the opposite of photosynthesis; it uses O2 to breakdown glucose into CO2 and H2O. It results in chemical cycling in biosphere. Respiration and Breathing: Respiration takes place in cells and needs O2 to breakdown food and releases the waste matter CO2. Breathing exchanges these gases between lungs and air. Overall equation for cellular respiration is: C6H1206 + O2 6CO2 + 6 H2O + ATP Glucose Oxygen Carbon Dioxide Water Energy Redox reactions: reduction-oxidation reactions. The gain of electrons during a chemical reaction is called Reduction. The loss of electrons during a chemical reaction is called Oxidation. Glucose is oxidized to 6CO2 and O2 is reduced to 6H2O during cellular respiration. During cellular respiration, glucose loses electrons and H, and O2 gains them. Energy and Food All living things need energy. Some living things can make their food from CO2 and H2O – Producers (plants, algae) Animals feeding on plants – herbivores (chipmunk) Animals feeding on animals – Carnivores (lion) Producers change solar energy to chemical energy of organic molecules – glucose, amino acids Animals and also plants break chemical bonds of sugar molecules and make ATP. Use ATP for all cellular functions 4 Main Step of Cellular Respiration Glycolysis: Glucose + 2NAD + 2ADP 2 Pyruvate + 2NADH + 2 ATP Preparatory Step: Pyruvate + NAD Acetyl-CoA + CO2 + NADH Krebs Cycle: Acetyl-CoA + NAD + FAD + ADP CO2 + NADH + FADH + ATP Electron Transport Chain: electrons of NADH + O2 ATP + H2O Cellular Respiration Aerobic Harvest of energy: is the main source of energy for most organisms.