DOCSLIB.ORG

Unit 6 Lecture 6 in OUR PREVIOUS LECTURE WE JUST BEGAN T

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Unit 6 Lecture 6 in OUR PREVIOUS LECTURE WE JUST BEGAN T CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 1 CHM 105/106 Program 53: Unit 6 Lecture 6 IN OUR PREVIOUS LECTURE WE JUST BEGAN TALKING ABOUT THE CHAPTER ON WHAT WE CALL BIOCHEMISTRY, WHICH IS THE CHEMISTRY DEALING WITH THE COMPOUNDS INVOLVED IN BIOLOGICAL PROCESSES, LIVING ORGANISMS, BOTH PLANT ANIMAL HUMAN. AND WE HAD JUST TAKEN A LOOK AT THE FIRST GROUP OF THE FOUR MAJOR GROUPS OF BIOCHEMICAL SPECIES THAT WE’RE GOING TO LOOK AT. WE’RE MENTIONED THAT WE’RE GONNA LOOK AT CARBOHYDRATES. WE’RE GOING TO LOOK AT THE LIPIDS. WE’RE GOING TO LOOK AT PROTEINS, AND WE’RE GOING TO LOOK AT NUCLEIC ACIDS, AND THEIR GENERAL STRUCTURE. THE FIRST ONE THAT WE MENTIONED AND BEGAN TO LOOK AT WERE THE CARBOHYDRATES, AND ONCE AGAIN THE CARBOHYDRATES ARE THOSE COMPOUNDS THAT CONTAIN CARBON, HYDROGEN, AND OXYGEN, AND SPECIFICALLY AS WE SAW YESTERDAY THAT THESE OFTEN CONTAIN THE FUNCTIONAL GROUPS OF ALDEHYDES AND KETONES AND ALCOHOLS. THOSE ARE THE THREE FUNCTIONAL GROUPS THAT WE SEE CONTAINED IN THE CARBOHYDRATES. THE SIMPLEST OF THE SUGARS, THE BUILDING BLOCK, THE SINGLE UNIT SUGARS AS WE REFER TO THEM ARE REFERRED TO AS THE MONOSACCHARIDES. MONO AS A PREFIX MEANS ONE AND THE SACCHARIDE IS THE SUGAR UNIT. YOU MIGHT RECOGNIZE THE LAST PART OF THAT, THE SACCHARIDE – ONE OF THE FIRST ARTIFICIAL SWEETENERS PRODUCED WAS CALLED SACCHARINE, AND THE NAME SACCHARINE CAME BECAUSE IT WAS A REPLACEMENT FOR NATURALLY OCCURRING SUGAR UNITS. WE STARTED ALSO BY TALKING ABOUT THE PENTOSE SUGARS WHICH THE PENT AS A PREFIX MEANS OF COURSE FIVE PENTANE, WE’RE TALKED ABOUT EARLIER IN ORGANIC CHEMISTRY. SO THE PENTOSE SUGARS ARE THOSE SUGARS CONTAINING FIVE CARBONS. NOW AGAIN PLEASE LET MENTION DON’T WORRY ABOUT DRAWING OUT ALL THESE STRUCTURES AS I PUT THEM UP TODAY – THAT’S NOT THE KEY THING. KEY THING HERE IS THAT WE HAVE APPLIED CARBON SUGAR. OKAY SO IF YOU RECOGNIZE PENT YOU WOULD RECOGNIZE THE FIVE CARBONS. THIS PARTICULAR SUGAR DOES HAVE, HOPEFULLY YOU COULD RECOGNIZE THAT GROUP UP THERE – THAT’S THE ALDEHYDE GROUP. AND OF COURSE THE OH’S OVER HERE ARE THE ALCOHOL GROUPS THAT WE’VE CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 2 TALKED ABOUT PREVIOUSLY IN ORGANIC CHEMISTRY. NOW EVEN THOUGH WE CAN DRAW THE MOLECULE IN A LINEAR FORM, AND EVEN THOUGH IT DOES EXIST OCCASIONALLY IN THE LINEAR FORM – BY THAT I MEAN THE CARBONS ARE ALL HOOKED UP IN A LINE, MORE FREQUENTLY IN NATURE WE FIND THE PENTOSE SUGARS, AND ACTUALLY WE’LL FIND THAT WE FIND MOST OF THE SUGARS IN WHAT WE CALL A HETEROCYCLIC FORM RATHER THAN IN A LINEAR FORM. NOW THAT’S NOT A NEW TERM TO US BECAUSE WE DID TALK ABOUT HETEROCYCLIC WHEN WE TALKED ABOUT AMINES. THE TERM HETEROCYCLIC, OF COURSE CYCLIC YOU COULD GUESS THAT MEANS THAT WE’RE GOING TO HOOK THINGS AROUND IN A CYCLE, BUT THE TERM HETEROCYCLIC MEANS THAT ONE OF THE ATOMS IN THE RING IS A NON- CARBON. OKAY HOMOCYCLIC WOULD BE SOMETHING LIKE THE BENZENE THAT WE TALKED ABOUT IN THE PREVIOUS LECTURE. THE BENZENE WITH SIX CARBON RING STRUCTURE IS A HOMOCYCLIC STRUCTURE. HETEROCYCLIC MEANS THAT ONE ATOM IN THE RING IS A NON- CARBON. SO IF WE HAD SOMETHING LIKE WE HAD LOOKED AT EARLIER IN THE YEAR, WE LOOKED AT SOMETHING LIKE THIS, WITH A HYDROGEN ON HERE AND A PAIR OF ELECTRONS, AND WE CALLED THAT A HETEROCYCLIC AMINE. THAT WAS AN AMINE. THE NITROGEN- HYDROGEN STRUCTURE IN THE OVERALL. THIS IS HETEROCYCLIC, AND AS I SAY IN MOST CASES WE REALLY FIND THE PENTOSE SUGARS THEN NOT IN A LINEAR FORM IN NATURE BUT RATHER IN THE HETEROCYCLIC FORM. SO LET’S TAKE A LOOK AT PENTOSE SUGAR THEN IN ITS HETEROCYCLIC FORM. WE HAVE TWO TYPES OF PENTOSE SUGARS AND WE’RE GOING TO COME BACK AND TALK ABOUT THESE EVEN FURTHER WHEN WE TALK ABOUT THE NUCLEIC ACIDS. THIS IS CALLED THE RIBOSE SUGAR, AND ACTUALLY THE RIBOSE SUGAR IS EXACTLY WHAT WE HAD JUST A MOMENT AGO IN THE LINEAR FORM EXCEPT THAT WE HAVE BENT IT AROUND AND HOOKED IT TOGETHER IN THAT OXYGEN THAT WAS THERE ON THE ALDEHYDE GROUP AND THEN WE STILL HAVE AN ALCOHOL, AN ALCOHOL, AN ALCOHOL, AND AN ALCOHOL. WE HAVE FOUR ALCOHOLS LIKE WE DID PREVIOUSLY. THIS PARTICULAR FORM IS CALLED RIBOSE. THAT LITTLE B IN FRONT OF IT IS A BETA RIBOSE BUT THAT’S NOT THAT ESSENTIAL TO US SO WE’LL ONLY CONCENTRATE ON THE RIBOSE PART. OKAY RIBOSE, AND THEN THE NEXT ONE TO IT, WHICH IS ALSO A PENTOSE SUGAR, IT STILL MEANS IT HAS TO HAVE FIVE CARBONS, AND THE CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 3 CARBONS IN THIS CASE THERE’S ONE CARBON THERE, EACH OF THESE CORNERS HERE ARE ACTUALLY CARBONS. SO THAT’S WHERE OUR FIVE CARBONS ARE IN THAT STRUCTURE. AND OVER HERE OF COURSE WE WOULD HAVE THE SAME THING. WE HAVE THESE FOUR CORNERS ARE CARBONS AND OF COURSE NOW THE FIFTH ONE UP THERE. SO THEY’RE BOTH PENTOSE SUGARS. RIBOSE, THIS IS CALLED DEOXYRIBOSE, AND THE NAME DEOXYRIBOSE COMES FROM THE FACT THAT IF YOU LOOK RIGHT HERE YOU NOTICE THAT THERE’S ONE LESS OXYGEN ON THIS MOLECULE THAN THERE IS ON THIS MOLECULE. THERE’S ONE LESS ALCOHOL GROUP ESSENTIALLY IN THE TWO. AND SO THE NAME DEOXY WHEN WE TALK ABOUT DETOXIFICATION, MEANING TO REMOVE SOMETHING THAT’S TOXIC, DEOXY MEANS MINUS AN OXYGEN AND SO THAT’S WHERE THE NAME COMES FROM. IT’S THE RIBO-SUGAR MINUS THE ONE OXYGEN AND THAT MAKES IT DEOXYRIBOSE SUGAR. NOW THESE TWO AS I SAY ARE IMPORTANT WHEN WE TALK ABOUT NUCLEIC ACIDS. THERE ARE TWO NUCLEIC ACIDS. DNA AND RNA, AND RNA STANDS FOR RIBONUCLEIC ACID. AND THE R COMES FROM THIS PART RIGHT HERE – RIBO-NUCLEIC ACID. DNA COMES FROM DEOXYRIBOSE, AND SO THAT’S WHERE THE NAME DNA COMES FROM. DEOXYRIBOSE NUCLEIC ACID. NOW OF COURSE THIS IS JUST ONE COMPONENT OF EACH OF THESE NUCLEIC ACIDS AND WE’LL LOOK AT THE NUCLEIC ACIDS IN GRATER DETAIL LATER, BUT OUR STARTING BLOCK THEN, OUR SIMPLEST OF OUR SUGARS ARE THEN THE PENTOSE SUGARS. NOW W E’LL GO UP ONE STEP AND WE’LL GO TO THE HEXOSE SUGARS, MEANING THAT WE’RE NOW LOOKING AT SOMETHING THAT HAS SIX CARBONS. WE HAVE SIX CARBONS – ONE, TWO, THREE, FOUR, FIVE, SIX CARBONS. NOTICE THAT EVERY ONE OF THE CARBONS HAS AN ALCOHOL GROUP ON IT AND THE END GROUP UP HERE IS ONCE AGAIN AN ALDEHYDE. AS A MATTER OF FACT THIS PARTICULAR SUGAR IS REFERRED TO AS AN ALDO- HEXOSE. SO THE ALDO TELLS US THAT IT HAS AN ALDEHYDE GROUP ON IT AND THE HEX OF COURSE SAYS THAT THERE’S SIX CARBONS THERE. SO THE NAME TELLS US WHAT THE STRUCTURE IS. THE COMMON NAME FOR THIS ALDOHEXOSE IS GLUCOSE. OR SOMETIMES IT’S ALSO CALLED DEXTROSE. BOTH OF THOSE – THE DEXTROSE IS THE JUST VERY GENERIC COMMON NAME, BUT GLUCOSE IS THE MORE COMMON NAME. SOMETIMES THIS IS ALSO CALLED GRAPE SUGAR. THIS IS THE SUGAR THAT WE FIND IN GRAPES. THIS IS THE SUGAR THAT CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 4 IS GOING TO BE FERMENTED TO ETHYL ALCOHOL WHEN WE PRODUCE WINE. THIS IS THE MATERIAL. REMEMBER WHEN WE LOOKED AT THE BEER AND WINE MAKING IN AN EARLIER CHAPTER WE TALKED ABOUT THE FACT THAT IN BEER MAKING WE ARE STARTING WITH LIKE STARCHES AND MUST CONVERT THEM TO SUGARS AND THEN FERMENT THEM. WHEN WE’RE MAKING WINE WE’RE ALREADY STARING WITH A NATURAL SUGAR THAT’S THERE IN THE GRAPE JUICE, AND ALL WE’RE DOING IS BRINING ABOUT THE FERMENTATION PROCESS. SO ALDOHEXOSE AND ALDEHYDE SIX CARBONS AND THE GRAPE SUGAR. WE ALSO HAVE A KETOHEXOSE. NOTICE HERE AGAIN WE STILL HAVE THE SIX CARBONS AND WE STILL HAVE FIVE ALCOHOL GROUPS BUT NOTICE THIS TIME THIS CARBON-DOUBLE BOND-OXYGEN INSTEAD OF BEING ON AN END CARBON WHICH IS TYPICAL OF THE ALDEHYDE IS ON A CARBON IN THE RING, I MEAN IN THE CHAIN. AND SO THIS MAKES THIS THEN INSTEAD OF BEING AN ALDEHYDE THIS TIME THIS IS A KETONE – AN R GROUP, AN R GROUP, AND THE C-DOUBLE BOND-O FOR THE KETONE. SO THIS IS REFERRED TO AS A KETO-HEXOSE. AND AGAIN THE KETO TELLS US WE’RE LOOKING FOR KETONE IN THE STRUCTURE – THE CARBON-DOUBLE BOND–OXYGEN IN THE RING, OR IN THE CHAIN. AND HEX, THAT WE HAVE THE SIX CARBONS. THIS IS CALLED FRUCTOSE. ALSO KNOWN AS LEVULOSE, BUT FRUCTOSE, AND IT’S FRUIT SUGAR. IT’S THE SUGAR THAT WE FIND IN THE REST OF THE FRUITS. SO WE HAVE THE GRAPE SUGAR, IF WE CAN GET BOTH OF THEM ON HERE FAIRLY CLOSE TO EACH OTHER. WE HAVE THE ONE THAT OCCURS IN GRAPES WHICH IS THE ALDEHYDE, AND THE ONE THAT OCCURS IN MOST OF THE OTHER FOODS – APPLES, PINEAPPLES, PEACHES, PEARS, WATERMELON, IS A FRUCTOSE. FRUIT SUGAR, AND IT’S A KETONE STRUCTURE. THAT’S THE ONLY DIFFERENCE IN THE TWO. OKAY, ALRIGHT, ANY QUESTIONS? NOW, LOOKING AT THE STRUCTURE THAT WE TYPICALLY FIND THEN, AGAIN THE LINEAR IS NICE LOOKING AT TO SEE THE FUNCTIONAL GROUPS, BUT IN REALITY MOST OF THESE STILL OCCUR IN NATURE IN A HETEROCYCLIC FORM. SO WE’RE GOING TO SHOW THESE NOW IN THE HETEROCYCLIC FORM.
Load more

Recommended publications
  • Pentose PO4 Pathway, Fructose, Galactose Metabolism.Pptx
    Pentose PO4 pathway, Fructose, galactose metabolism The Entner Doudoroff pathway begins with hexokinase producing Glucose 6 PO4 , but produce only one ATP. This pathway prevalent in anaerobes such as Pseudomonas, they doe not have a Phosphofructokinase. The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) is a biochemical pathway parallel to glycolysis that generates NADPH and pentoses. While it does involve oxidation of glucose, its primary role is anabolic rather than catabolic. There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol. For each mole of glucose 6 PO4 metabolized to ribulose 5 PO4, 2 moles of NADPH are produced. 6-Phosphogluconate dh is not only an oxidation step but it’s also a decarboxylation reaction. The primary results of the pathway are: The generation of reducing equivalents, in the form of NADPH, used in reductive biosynthesis reactions within cells (e.g. fatty acid synthesis). Production of ribose-5-phosphate (R5P), used in the synthesis of nucleotides and nucleic acids. Production of erythrose-4-phosphate (E4P), used in the synthesis of aromatic amino acids. Transketolase and transaldolase reactions are similar in that they transfer between carbon chains, transketolases 2 carbon units or transaldolases 3 carbon units. Regulation; Glucose-6-phosphate dehydrogenase is the rate- controlling enzyme of this pathway. It is allosterically stimulated by NADP+. The ratio of NADPH:NADP+ is normally about 100:1 in liver cytosol.
    [Show full text]
  • Lecture 7 - the Calvin Cycle and the Pentose Phosphate Pathway
    Lecture 7 - The Calvin Cycle and the Pentose Phosphate Pathway Chem 454: Regulatory Mechanisms in Biochemistry University of Wisconsin-Eau Claire 1 Introduction The Calvin cycle Text The dark reactions of photosynthesis in green plants Reduces carbon from CO2 to hexose (C6H12O6) Requires ATP for free energy and NADPH as a reducing agent. 2 2 Introduction NADH versus Text NADPH 3 3 Introduction The Pentose Phosphate Pathway Used in all organisms Glucose is oxidized and decarboxylated to produce reduced NADPH Used for the synthesis and degradation of pentoses Shares reactions with the Calvin cycle 4 4 1. The Calvin Cycle Source of carbon is CO2 Text Takes place in the stroma of the chloroplasts Comprises three stages Fixation of CO2 by ribulose 1,5-bisphosphate to form two 3-phosphoglycerate molecules Reduction of 3-phosphoglycerate to produce hexose sugars Regeneration of ribulose 1,5-bisphosphate 5 5 1. Calvin Cycle Three stages 6 6 1.1 Stage I: Fixation Incorporation of CO2 into 3-phosphoglycerate 7 7 1.1 Stage I: Fixation Rubisco: Ribulose 1,5- bisphosphate carboxylase/ oxygenase 8 8 1.1 Stage I: Fixation Active site contains a divalent metal ion 9 9 1.2 Rubisco Oxygenase Activity Rubisco also catalyzes a wasteful oxygenase reaction: 10 10 1.3 State II: Formation of Hexoses Reactions similar to those of gluconeogenesis But they take place in the chloroplasts And use NADPH instead of NADH 11 11 1.3 State III: Regeneration of Ribulose 1,5-Bisphosphosphate Involves a sequence of transketolase and aldolase reactions. 12 12 1.3 State III:
    [Show full text]
  • The Pentose Phosphate Pathway and Its Involvement in Cisplatin Resistance
    International Journal of Molecular Sciences Review The Pentose Phosphate Pathway and Its Involvement in Cisplatin Resistance Isabella Giacomini 1, Eugenio Ragazzi 1 , Gianfranco Pasut 2 and Monica Montopoli 1,3,* 1 Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo Egidio Meneghetti 2, 35131 Padova, Italy; [email protected] (I.G.); [email protected] (E.R.) 2 Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131 Padova, Italy; [email protected] 3 Veneto Institute of Molecular Medicine, Via Giuseppe Orus 2, 35129 Padova, Italy * Correspondence: [email protected]; Tel.: +39-049-827-5090 Received: 30 December 2019; Accepted: 29 January 2020; Published: 31 January 2020 Abstract: Cisplatin is the first-line treatment for different types of solid tumors, such as ovarian, testicular, bladder, cervical, head and neck, lung, and esophageal cancers. The main problem related to its clinical use is the onset of drug resistance. In the last decades, among the studied molecular mechanisms of cisplatin resistance, metabolic reprogramming has emerged as a possible one. This review focuses on the pentose phosphate pathway (PPP) playing a pivotal role in maintaining the high cell proliferation rate and representing an advantage for cancer cells. In particular, the oxidative branch of PPP plays a role in oxidative stress and seems to be involved in cisplatin resistance. In light of these considerations, it has been demonstrated that overexpression and higher enzymatic activity of different enzymes of both oxidative and non-oxidative branches (such as glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and transketolase) increase cisplatin resistance, and their silencing or combined treatment with cisplatin could restore cisplatin sensitivity.
    [Show full text]
  • Carbohydrates: Structure and Function
    CARBOHYDRATES: STRUCTURE AND FUNCTION Color index: . Very important . Extra Information. “ STOP SAYING I WISH, START SAYING I WILL” 435 Biochemistry Team *هذا العمل ﻻ يغني عن المصدر المذاكرة الرئيسي • The structure of carbohydrates of physiological significance. • The main role of carbohydrates in providing and storing of energy. • The structure and function of glycosaminoglycans. OBJECTIVES: 435 Biochemistry Team extra information that might help you 1-synovial fluid: - It is a viscous, non-Newtonian fluid found in the cavities of synovial joints. - the principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement O 2- aldehyde = terminal carbonyl group (RCHO) R H 3- ketone = carbonyl group within (inside) the compound (RCOR’) 435 Biochemistry Team the most abundant organic molecules in nature (CH2O)n Carbohydrates Formula *hydrate of carbon* Function 1-provides important part of energy Diseases caused by disorders of in diet . 2-Acts as the storage form of energy carbohydrate metabolism in the body 3-structural component of cell membrane. 1-Diabetesmellitus. 2-Galactosemia. 3-Glycogen storage disease. 4-Lactoseintolerance. 435 Biochemistry Team Classification of carbohydrates monosaccharides disaccharides oligosaccharides polysaccharides simple sugar Two monosaccharides 3-10 sugar units units more than 10 sugar units Joining of 2 monosaccharides No. of carbon atoms Type of carbonyl by O-glycosidic bond: they contain group they contain - Maltose (α-1, 4)= glucose + glucose -Sucrose (α-1,2)= glucose + fructose - Lactose (β-1,4)= glucose+ galactose Homopolysaccharides Heteropolysaccharides Ketone or aldehyde Homo= same type of sugars Hetero= different types Ketose aldose of sugars branched unBranched -Example: - Contains: - Contains: Examples: aldehyde group glycosaminoglycans ketone group.
    [Show full text]
  • 1. Nucleotides A. Pentose Sugars – 5-Carbon Sugar 1) Deoxyribose – in DNA 2) Ribose – in RNA B. Phosphate Group C. Nitroge
    1. Nucleotides a. Pentose sugars – 5-Carbon sugar 1) Deoxyribose – in DNA 2) Ribose – in RNA b. Phosphate group c. Nitrogenous bases 1) Purines a) Adenine b) Guanine 2) Pyrimidines a) Cytosine b) Thymine 2. Types of Nucleic Acids a. DNA 1) Locations 2) Functions b. RNA 1) Locations 2) Functions E. High Energy Biomolecules 1. Adenosine triphosphate a. Uses 1) Active transport 2) Movement 3) Biosynthesis reactions b. Regeneration 1) ADP + Pi + Energy → ATP 4. Classes of proteins a. Structural – ex. Collagen, keratin b. Transport – Hemoglobin, many β-globulins c. Contractile – Actin and Myosin of muscle tissue d. Regulatory - Hormones e. Immunologic - Antibodies f. Clotting – Thrombin and Fibrin g. Osmotic - Albumin h. Catalytic – Enzymes 1) Characteristics of enzymes • Proteins (most); ribonucleoproteins (few/ribozymes) • Act as organic catalysts • Lower the activation energy of reactions • Not changed by the reaction • Bind to their substrates o Lock-and-key model of enzyme activity o Induced-fit model • Highly specific • Named by adding -ase to substrate name; e.g., maltose/maltase • May require cofactors which may be: o Nonprotein metal ions such as copper, manganese, potassium, sodium o Small organic molecules known as coenzymes. The B vitamins like thiamine (B1) riboflavin (B2) and nicotinamide are precursors of coenzymes. • May require activation; e.g., pepsinogen pepsin in stomach chief cells 4. Factors Affecting Enzyme Action • pH o pepsin (stomach) @ pH = 2; trypsin (small int.) @ pH = 8 • Temperature o Denatured by high temp’s. • Enzyme inhibitors o Competitive inhibitors o Noncompetitive inhibitors • Effect of substrate concentration and reversible reactions and the Law of Mass D.
    [Show full text]
  • PENTOSE PHOSPHATE PATHWAY — Restricted for Students Enrolled in MCB102, UC Berkeley, Spring 2008 ONLY
    Metabolism Lecture 5 — PENTOSE PHOSPHATE PATHWAY — Restricted for students enrolled in MCB102, UC Berkeley, Spring 2008 ONLY Bryan Krantz: University of California, Berkeley MCB 102, Spring 2008, Metabolism Lecture 5 Reading: Ch. 14 of Principles of Biochemistry, “Glycolysis, Gluconeogenesis, & Pentose Phosphate Pathway.” PENTOSE PHOSPHATE PATHWAY This pathway produces ribose from glucose, and it also generates 2 NADPH. Two Phases: [1] Oxidative Phase & [2] Non-oxidative Phase + + Glucose 6-Phosphate + 2 NADP + H2O Ribose 5-Phosphate + 2 NADPH + CO2 + 2H ● What are pentoses? Why do we need them? ◦ DNA & RNA ◦ Cofactors in enzymes ● Where do we get them? Diet and from glucose (and other sugars) via the Pentose Phosphate Pathway. ● Is the Pentose Phosphate Pathway just about making ribose sugars from glucose? (1) Important for biosynthetic pathways using NADPH, and (2) a high cytosolic reducing potential from NADPH is sometimes required to advert oxidative damage by radicals, e.g., ● - ● O2 and H—O Metabolism Lecture 5 — PENTOSE PHOSPHATE PATHWAY — Restricted for students enrolled in MCB102, UC Berkeley, Spring 2008 ONLY Two Phases of the Pentose Pathway Metabolism Lecture 5 — PENTOSE PHOSPHATE PATHWAY — Restricted for students enrolled in MCB102, UC Berkeley, Spring 2008 ONLY NADPH vs. NADH Metabolism Lecture 5 — PENTOSE PHOSPHATE PATHWAY — Restricted for students enrolled in MCB102, UC Berkeley, Spring 2008 ONLY Oxidative Phase: Glucose-6-P Ribose-5-P Glucose 6-phosphate dehydrogenase. First enzymatic step in oxidative phase, converting NADP+ to NADPH. Glucose 6-phosphate + NADP+ 6-Phosphoglucono-δ-lactone + NADPH + H+ Mechanism. Oxidation reaction of C1 position. Hydride transfer to the NADP+, forming a lactone, which is an intra-molecular ester.
    [Show full text]
  • Questions with Answers- Nucleotides & Nucleic Acids A. the Components
    Questions with Answers- Nucleotides & Nucleic Acids A. The components and structures of common nucleotides are compared. (Questions 1-5) 1._____ Which structural feature is shared by both uracil and thymine? a) Both contain two keto groups. b) Both contain one methyl group. c) Both contain a five-membered ring. d) Both contain three nitrogen atoms. 2._____ Which component is found in both adenosine and deoxycytidine? a) Both contain a pyranose. b) Both contain a 1,1’-N-glycosidic bond. c) Both contain a pyrimidine. d) Both contain a 3’-OH group. 3._____ Which property is shared by both GDP and AMP? a) Both contain the same charge at neutral pH. b) Both contain the same number of phosphate groups. c) Both contain the same purine. d) Both contain the same furanose. 4._____ Which characteristic is shared by purines and pyrimidines? a) Both contain two heterocyclic rings with aromatic character. b) Both can form multiple non-covalent hydrogen bonds. c) Both exist in planar configurations with a hemiacetal linkage. d) Both exist as neutral zwitterions under cellular conditions. 5._____ Which property is found in nucleosides and nucleotides? a) Both contain a nitrogenous base, a pentose, and at least one phosphate group. b) Both contain a covalent phosphodister bond that is broken in strong acid. c) Both contain an anomeric carbon atom that is part of a β-N-glycosidic bond. d) Both contain an aldose with hydroxyl groups that can tautomerize. ___________________________________________________________________________ B. The structures of nucleotides and their components are studied. (Questions 6-10) 6._____ Which characteristic is shared by both adenine and cytosine? a) Both contain one methyl group.
    [Show full text]
  • Multi-Enzymatic Cascades in the Synthesis of Modified Nucleosides
    biomolecules Article Multi-Enzymatic Cascades in the Synthesis of Modified Nucleosides: Comparison of the Thermophilic and Mesophilic Pathways Ilja V. Fateev , Maria A. Kostromina, Yuliya A. Abramchik, Barbara Z. Eletskaya , Olga O. Mikheeva, Dmitry D. Lukoshin, Evgeniy A. Zayats , Maria Ya. Berzina, Elena V. Dorofeeva, Alexander S. Paramonov , Alexey L. Kayushin, Irina D. Konstantinova * and Roman S. Esipov Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Miklukho-Maklaya 16/10, 117997 GSP, B-437 Moscow, Russia; [email protected] (I.V.F.); [email protected] (M.A.K.); [email protected] (Y.A.A.); [email protected] (B.Z.E.); [email protected] (O.O.M.); [email protected] (D.D.L.); [email protected] (E.A.Z.); [email protected] (M.Y.B.); [email protected] (E.V.D.); [email protected] (A.S.P.); [email protected] (A.L.K.); [email protected] (R.S.E.) * Correspondence: [email protected]; Tel.: +7-905-791-1719 ! Abstract: A comparative study of the possibilities of using ribokinase phosphopentomutase ! nucleoside phosphorylase cascades in the synthesis of modified nucleosides was carried out. Citation: Fateev, I.V.; Kostromina, Recombinant phosphopentomutase from Thermus thermophilus HB27 was obtained for the first time: M.A.; Abramchik, Y.A.; Eletskaya, a strain producing a soluble form of the enzyme was created, and a method for its isolation and B.Z.; Mikheeva, O.O.; Lukoshin, D.D.; chromatographic purification was developed. It was shown that cascade syntheses of modified nu- Zayats, E.A.; Berzina, M.Y..; cleosides can be carried out both by the mesophilic and thermophilic routes from D-pentoses: ribose, Dorofeeva, E.V.; Paramonov, A.S.; 2-deoxyribose, arabinose, xylose, and 2-deoxy-2-fluoroarabinose.
    [Show full text]
  • DNA Stands for Deoxyribose Nucleic Acid
    DNA and Protein Synthesis DNA • DNA stands for deoxyribose nucleic acid. • This chemical substance is found in the nucleus of all cells in all living organisms • DNA controls all the chemical changes which take place in cells • The kind of cell which is formed, (muscle, blood, nerve etc) is controlled by DNA Ribose is a sugar, like glucose, but with only five carbon atoms in its molecule. Deoxyribose is almost the same but lacks one oxygen atom. The nitrogen bases are: o ADENINE (A) o THYMINE (T) o CYTOSINE (C) o GUANINE (G) Nucleotides • A molecule of DNA is formed by millions of nucleotides joined together in a long chain. • DNA is a very large molecule made up of a long chain of sub-units. • The sub-units are called nucleotides. • Each nucleotide is made up of a sugar called deoxyribose, a phosphate group -PO4 and an organic (Nitrogen) base: A, T, C, G BASE PAIRING RULE amount of C= amount of G AND amount of A= amount of T • Adenine always pairs with thymine, and guanine always pairs with cytosine. DNA STRUCTURE • The nucleotide bases will point to the inside of the DNA molecule while the outside (backbone) of the DNA molecule will be made of the sugar and phosphate molecules. • When complete the DNA molecule forms a double helix (two spiral sides wrapped together). • The paired strands are coiled into a spiral called A DOUBLE HELIX. Genes • Each chromosome contains hundreds of genes. • Most of your characteristics: hair color, height, how things taste to a person, are determined by the kinds of proteins cells make (gene).
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8,604,000 B2 De Kort Et Al
    USOO8604000B2 (12) United States Patent (10) Patent No.: US 8,604,000 B2 de Kort et al. (45) Date of Patent: Dec. 10, 2013 (54) PALATABLE NUTRITIONAL COMPOSITION 2011/0027391 A1 2/2011 De Kort et al. COMPRISING ANUCLEOTDE AND/ORA 2013, OO12469 A1 1/2013 De Kort et al. NUCLEOSDE AND A TASTE MASKING 2013, OO18012 A1 1/2013 Hageman et al. AGENT FOREIGN PATENT DOCUMENTS (75) Inventors: Esther Jacqueline de Kort, Wageningen EP O 175468 A2 3, 1986 (NL); Martine Groenendijk, EP 1216 041 B1 6, 2002 EP 1282 365 B1 2, 2003 Barendrecht (NL); Patrick Joseph EP 1656 839 A1 5, 2006 Gerardus Hendrikus Kamphuis, EP 1666 092 A2 6, 2006 Utrecht (NL) EP 18OO 675 A1 6, 2007 JP 64-080250 A 3, 1989 (73) Assignee: N.V. Nutricia, Zoetermeer (NL) JP 06-237734. A 8, 1994 JP 10-004918 A 1, 1998 JP 10-136937 A 5, 1998 (*) Notice: Subject to any disclaimer, the term of this JP 11-071274. A 3, 1999 patent is extended or adjusted under 35 WO WO-0038829 A1 T 2000 U.S.C. 154(b) by 213 days. WO WO-01 (32034 A1 5, 2001 WO WO-02/088159 A1 11, 2002 WO WO-02/096464 A1 12/2002 (21) Appl. No.: 12/809,431 WO WO-03 (013276 A1 2, 2003 WO WO-03/041701 A2 5, 2003 (22) PCT Filed: Dec. 22, 2008 WO WO-2005/039597 A2 5, 2005 WO WO-2006/031683 A2 3, 2006 (86). PCT No.: PCT/NL2O08/050843 WO WO-2006,118665 A2 11/2006 WO WO-2006, 127620 A2 11/2006 S371 (c)(1), WO WO-2007/001883 A2 1, 2007 (2), (4) Date: Dec.
    [Show full text]
  • Nucleosides & Nucleotides
    Nucleosides & Nucleotides Biochemistry Fundamentals > Genetic Information > Genetic Information NUCLEOSIDE AND NUCLEOTIDES SUMMARY NUCLEOSIDES  • Comprise a sugar and a base NUCLEOTIDES  • Phosphorylated nucleosides (at least one phosphorus group) • Link in chains to form polymers called nucleic acids (i.e. DNA and RNA) N-BETA-GLYCOSIDIC BOND  • Links nitrogenous base to sugar in nucleotides and nucleosides • Purines: C1 of sugar bonds with N9 of base • Pyrimidines: C1 of sugar bonds with N1 of base PHOSPHOESTER BOND • Links C3 or C5 hydroxyl group of sugar to phosphate NITROGENOUS BASES  • Adenine • Guanine • Cytosine • Thymine (DNA) 1 / 8 • Uracil (RNA) NUCLEOSIDES • =sugar + base • Adenosine • Guanosine • Cytidine • Thymidine • Uridine NUCLEOTIDE MONOPHOSPHATES – ADD SUFFIX 'SYLATE' • = nucleoside + 1 phosphate group • Adenylate • Guanylate • Cytidylate • Thymidylate • Uridylate Add prefix 'deoxy' when the ribose is a deoxyribose: lacks a hydroxyl group at C2. • Thymine only exists in DNA (deoxy prefix unnecessary for this reason) • Uracil only exists in RNA NUCLEIC ACIDS (DNA AND RNA)  • Phosphodiester bonds: a phosphate group attached to C5 of one sugar bonds with - OH group on C3 of next sugar • Nucleotide monomers of nucleic acids exist as triphosphates • Nucleotide polymers (i.e. nucleic acids) are monophosphates • 5' end is free phosphate group attached to C5 • 3' end is free -OH group attached to C3 2 / 8 FULL-LENGTH TEXT • Here we will learn about learn about nucleoside and nucleotide structure, and how they create the backbones of nucleic acids (DNA and RNA). • Start a table, so we can address key features of nucleosides and nucleotides. • Denote that nucleosides comprise a sugar and a base.
    [Show full text]
  • Part 1 in Our Series of Carbohydrate Lectures. in This Section, You Will Learn About Monosaccharide Structure
    Welcome to Part 1 in our series of Carbohydrate lectures. In this section, you will learn about monosaccharide structure. The building blocks of larger carbohydrate polymers. 1 First, let’s review why learning about carbohydrates is important. Carbohydrates are used by biological systems as fuels and energy resources. Carbohydrates typically provide quick energy and are one of the primary energy storage forms in animals. Carbohydrates also provide the precursors to other major macromolecules within the body, including the deoxyribose and ribose required for nucleic acid biosynthesis. Carbohydrates can also provide structural support and cushioning/shock absorption, as well as cell‐cell communication, identification, and signaling. 2 Carbohydrates, as their name implies, are water hydrates of carbon, and they all have the same basic core formula (CH2O)n and are always found in the ratio of 1 carbon to 2 hydrogens to 1 oxygen (1:2:1) making them easy to identify from their molecular formula. 3 Carbohydrates can be divided into subcategories based on their complexity. The simplest carbohydrates are the monosaccharides which are the simple sugars required for the biosynthesis of all the other carbohydrate types. Disaccharides consist of two monosaccharides that have been joined together by a covalent bond called the glycosidic bond. Oligosaccharides are polymers that consist of a few monosaccharides covalently linked together, and Polysaccharides are large polymers that contain hundreds to thousands of monosaccharide units all joined together by glycosidic bonds. The remainder of this lecture will focus on monosaccharides 4 Monosaccharides all have alcohol functional groups associated with them. In addition they also have one additional functional group, either an aldehyde or a ketone.
    [Show full text]