DOCSLIB.ORG

ACTION SPECTRUM for FERRICYANIDE PHOTOREDUCTION and REDOX POTENTIAL of CHLOROPHYLL 683* by TAKEKAZU Horiot and ANTHONY SAN PIETRO

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ACTION SPECTRUM for FERRICYANIDE PHOTOREDUCTION and REDOX POTENTIAL of CHLOROPHYLL 683* by TAKEKAZU Horiot and ANTHONY SAN PIETRO 1226 BIOCHEMISTRY: HORIO AND SAN PIETRO PROC. N. A. S. ment had taken place, the centrifugation carried out at 00 did not reverse. This specific binding appears to he the initial and sometimes rate-limliting step in amino acid polymerization. The author would like to express his indebtedness to Dr. Fritz Lipmann, in whose laboratory this investigation was carried out, for his support and encouragement. * This work was supported in part by a grant from the National Science Foundation, and repre- sents a portion of the thesis submitted by the author to the faculty of The Rockefeller Institute in partial fulfillment of the requirements for the degree of Doctor of Philosophy. t Present address: Biological Laboratories, Harvard University. 1 Spyrides, G. J., and F. Lipmann, these PROCEEDINGS, 48, 1977 (1962). 2 Barondes, S. H., and M. W. Nirenberg, Science, 138, 810 (1962). 3 Gilbert, W., J. Mol. Biol., 6, 374 (1963). 4Spyrides, G. J., Ph. D. dissertation, The Rockefeller Institute (1963). 5 Conway, T. W., these PROCEEDINGS, 51, 1216 (1964). 6 Nakamoto, T., and F. Lipmann, Federation Proc., 23, 219 (1964). 7Lubin, M., Biochim. Biophys. Acta, 72, 345 (1963). 8 Nakamoto, T., T. W. Conway, J. E. Allende, G. J. Spyrides, and F. Lipmann, in Synthesis and Structure of Macromolecules, Cold Spring Harbor Symposia on Quantitative Biology, vol. 28 (1963), p. 227. 9 Kaji, A., and H. Kaji, Biochem. Biophys. Res. Commun, 13, 186 (1963). 10 Cannon, M., R. Krug, and W. Gilbert, J. Mol. Biol., 7, 360 (1963). ACTION SPECTRUM FOR FERRICYANIDE PHOTOREDUCTION AND REDOX POTENTIAL OF CHLOROPHYLL 683* BY TAKEKAZU HORIOt and ANTHONY SAN PIETRO CHARLES F. KETTERING RESEARCH LABORATORY, YELLOW SPRINGS, OHIO Communicated by Martin D. Kamen, April 27, 1964 Nearly thirty years ago, Hill1-4 discovered that chloroplasts isolated from green leaves liberate molecular oxygen upon illumination when an appropriate hydrogen acceptor (Hill oxidant) is provided. It is now generally accepted that this reaction represents the photochemical step in photosynthesis. Meanwhile, the possible photochemical function of the pigments associated with chloroplasts, namely, the chlorophylls and carotenoids, has been examined by a number of investigators.5-'0 Chen measured the action spectrum for photoreduc- tion of 2,6-dichlorophenol indophenol by chloroplasts from Swiss chard.11 The action spectrum for this reaction coincided well with the action spectrum for photo- synthetic oxygen evolution as well as with the absorption spectrum of the chloro- plasts. Action spectra for NADP photoreduction and the coupled phosphorylation, measured by San Pietro et al.,12 Black et al., 13 and Jagendorf et al.14 coincided with the absorption spectrum of the chloroplasts. We have studied the action spectra for the photoreduction of ferricyanide and the coupled phosphorylation and found that the resultant action spectra differ from the absorption spectrum of the chloroplasts. In addition, we have determined the redox potential of the chlorophyll component with an absorption maximum at 683 mtu. Downloaded by guest on September 30, 2021 VOL. 51, 1964 BIOCHEMISTRY: HORIO AND SAN PIETRO 1227 Materials and Methods.-Washed chloroplasts were prepared from fresh spinach leaves according to the method of Keister et al.15 or of Stiller and Vennesland.16 Similar results were obtained with either chloroplast preparation. Chlorophyll content of chloroplasts was determined by the method of Arnon. 17 Absorption spectra were measured with a Cary model 14 spectrophotometer. In some experiments, the spectrophotometer was equipped with a Cary scatter attachment. Photoreduction of ferricyanide and the coupled phosphorylation were measured by the method of Stiller and Vennesland16 except that the amount of radioactive orthophosphate (Pi32) incorporated into ATP was determined according to the method of Nielsen and Lehninger'8 as modified by Avron.'9 Components of the reaction mixture were 0.05 Al Tris-HCl buffer, pH 8, 0.035 N NaCl, 0.002 Al potas- sium ferricyanide, 0.005 M 1\gCl2, 0.0025 M ADP, 0.0025 M Pi32, and spinach chloroplasts (equivalent to approximately 20 ,ug/ml of chlorophyll) final vol- ume, 2 ml. Reactions were carried out at 150 in the light or dark for 3 min in capped cylindrical cuvettes (2 cm in diameter, 1 cm optical path). Reactions were terminated by the addition of 0.50 ml of ice-cold 20 per cent trichloroacetic acid solution, followed by centrifugation. The supernatant solutions were used to determine the change in absorption at 420 my and the amount of Pi32 incorporated into ATP. Photosynthetic pyridine nucleotide reductase (PPNR) was purified from spinach leaves as described by San Pietro.20 The purification was carried through the Dowex-Bentonite step20 and the protein concentrated by adsorption on and elution from DEAE cellulose. The ratio of absorbance at 330 m/A to that at 280 m/A of the PPNR was about 0.65. The redox potential of the chlorophyll component with an absorption maximum at 683 mui was determined according to the method of Davenport and Hill.21 Experimental Results.-Photoreduction of ferricyanide: The action spectra for both the photoreduction of ferricyanide and the coupled phosphorylation are very similar (Fig. 1), but significantly different from the absorption spectrum of the chloroplasts (Fig. 2). It is known that as chloroplasts age they lose photophos- phorylative activity more rapidly than they do photoreductive activity. The ac- tion spectrum for ferricyanide photoreduction was essentially the same regardless of the age of the chloroplasts. The ratios of activity with 650 mp illumination to that with 680 m1A illumination (Fig. 1) were 1.01 and 0.93, respectively, for ferri- cyanide photoreduction and the coupled phosphorylation with fresh chloroplasts, and 1.19 for ferricyanide photoreduction with aged, nonphotophosphorylating chloroplasts. Effect offerricyanide on absorption spectrum of spinach chloroplasts: With spinach chloroplasts, the absorption maximum at 679 mMu decreases upon the addition of ferricyanide and shifts to a shorter wavelength (Fig. 3), i.e., toward 670 m/u. The difference spectrum, "+ none" minus "+ ferricyanide," indicated that only the component possessing an absorption maximum at 683 m/u was bleached (Fig. 4). Relative to the ferri-ferrocyanide system, the redox potential of the component ab- sorbing at 683 mp was determined to be approximately +0.55 volt at pH 8. Photoreduction of PPNR: The anaerobic photoreduction of PPNR in the pres- ence of ascorbate is shown in Figure 5. When the photoreduced PPNR was re- Downloaded by guest on September 30, 2021 1228 BIOCHEMISTRY: HORIO AND SAN PIETRO PROC. N. A. S. 100100/Q 0.13 901 8g0 REDUCTION 0.8. >70 - I- 60 .,;s0 A ATP FORMATION 0.6. N50i Z40- 0.5 0F0.4- 20- 10 0.3. 600 650 700 0.1 . WAVELENGTH (mya) FIG. 1.-Action spectra for the 0.1 photoreduction of ferricyanide and the coupled phosphorylation. ° . .O Monochromatic light was ob- -°Goo Leo 70700 5 tained from a 1-meter grating WENWAVELENGTH (uy) monochromator (Bausch and Lomb) with a Sylvania Sun Gun FIG. 2.-Absorption spectrum as light source. The action spectra of spinach chloroplasts. Chloro- were determined with equal inci- plasts (equivalent to 12.5 jg per dent light energy (104 ergs/cm2/ ml of chlorophyll) in 0.05 M Tris- sec). At the wavelength of 660 HC1 buffer, pH 8, containing 0.01 mg, the reaction rates were 166 M KCL. The spectrophotometer ,umoles of ferricyanide reduced and was equipped with the scatter at- 67 umoles of ATP formed per hr tachment. per mg of chlorophyll. 0. 0.8 0.705~~~~/ 0.6 z. 0.4U4M A. 0.3 T 0.2 z 0.1 0.~~~~~~~~~~~~~~~~bUi. 600 650 700......... WAVELENGTH Amy) 550 600 650 700 WAVELENGTH (mp) FIG. 3.-Effect of ferricyanide on absorption spectrum of spinach FIG. 4.-Dlfference spectrum of chloroplasts. Chloroplasts (equiv- spinach with and alent to 20 ,ug per ml of chloro- without ferricyanide.chloroplaste Experi- phyll) in 0.05 M Tris-HCl buffer, mental conditions as for Fig. 3 pH 8, containing 0.01 M KC1. except that the amount of The absorption spectra were meas- plasts present was equivalentchtoro-to 40 ured everv 10 min after the addi- Mg per ml of chlorophyll. tion of ferricyanide (0.29 M). Downloaded by guest on September 30, 2021 VOL. 51, 1964 BIOCHEMISTRY: HORIO AND SAN PIETRO 1229 0.9 .I.. 0.8 (C)+NADP IN DARK (D) FIG. 5.-Photoreduction of PPNR and reoxidation by NADP. 0.7 _ The reaction mixture, containing ORIGINALOXIDIZED PPNR (A) chloroplasts equivalent to 3.6 Ag 0.6 V per ml of chlorophyll, 0.05 M ascorbate, PPNR, and buffer, was prepared in a Thunberg-type cu- - Ecu vette. To provide anaerobic con- A\\\A ditions, the cuvette was evacuated 0.4 -. and flushed with argon several times and finally filled with argon. 0.3 - (A) prior to illumination; (B) after 5 min in light (approximately 0.2 . PPNR PHOTOREDUCED 1000 ft-c); (C) after25or30minPATLY() in light; (D) NADP (500 JM) oP COMPLETEALLY( added to (C). C . o0..I..I..0.... 300 350 I 400...I.|450 500 560 600 WAVELENGTH (Cm) oxidized by NADP in the presence of chloroplasts in the dark, there was complete restoration of the original spectrum of the protein and the appearance of NADPH. In six experiments, the ratio for the number of moles of photoreduced PPNR re- quired to reduce one mole of NADP varied from 1.85 to 2.37. This stoichiometry is in excellent agreement with the data of Whatley et al.22 and Fry et al.21 Discussion.-The action spectrum for a photosynthetic or photochemical reac- tion with chloroplasts should provide information as to which pigment(s) is in- volved and, possibly, to what extent. Theoretically, the action spectrum should parallel the absorption spectrum of the substance responsible for the absorption of light.
Load more

Recommended publications
  • Algal Accessory Pigment Detection Using Aviris Image
    ALGAL ACCESSORY PIGMENT DETECTION USING AVIRIS IMAGE-DERIVED SPECTRAL RADIANCE DATA hurie L. Richardson, Florida International University, Miami, Florida, and Vincent G. Ambrosia, JCWS, Inc., NASA Ames Research Center, Moffett Field, California. 1. INTRODUCTION Visual and derivative analyses of AVIRIS spectral data can be used to detect algal accessory pigments in squat ic communities (Richardson et al. 1994). This capability extends the use of remote sensing for the study of aquatic ecosystems by allowing detection of taxonomically significant pigment signatures which yield information about the type of algae present. Such information allows remote sensing-based assessment of squat ic ecosystem health, as in the detection of nuisance blooms of cyanobacteria (Dekker et al., 1992) or toxic blooms of dinoflagellates (Carder and Steward, 1985). Remote sensing of aquatic systems has traditionally focused on quantification of chlorophyll a, a photoreactive (and light-harvesting) pigment which is common to all algae as well as cyanobacteria (bIuegrcxm algae). Due to the ubiquitousness of this pigment within algae, chl a is routinely measured to estimate algal biomass both during ground-truthing and using various airborne or satellite based sensors (Clark, 1981; Smith and Baker, 1982; Galat and Verdin, 1989; Mittenzwey et al., 1992), including AVIRIS (Hamilton et al., 1993). Within the remote sensing and aquatic sciences communities, ongoing research has been performed to detect algal accessory pigments for assessment of algal population composition (Gieskew 1991; Millie et al., 1993; Richardson, 1996). This research is based on the fact that many algal accessory pigments are taxonomically significant, and all are spectrally unique (Foppen, 1971; Morton, 1975; Bj#mland and Liaaen- Jensen, 1989; Rowan, 1989), Aquatic scientists have been refining pigment analysis techniques, primarily high performance liquid chromatography, or HPLC, (e.g.
    [Show full text]
  • Characterizing the Absorption Properties for Remote Sensing of Three Small Optically-Diverse South African Reservoirs
    Remote Sens. 2013, 5, 4370-4404; doi:10.3390/rs5094370 OPEN ACCESS Remote Sensing ISSN 2072-4292 www.mdpi.com/journal/remotesensing Article Characterizing the Absorption Properties for Remote Sensing of Three Small Optically-Diverse South African Reservoirs Mark William Matthews 1;* and Stewart Bernard 1;2 1 Marine Remote Sensing Unit, Department of Oceanography, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa 2 Earth Systems Earth Observation, Council for Scientific and Industrial Research, 15 Lower Hope Street, Rosebank, 7700 Cape Town, South Africa; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +27-216-505-775. Received: 16 July 2013; in revised form: 30 August 2013 / Accepted: 3 September 2013 / Published: 9 September 2013 Abstract: Characterizing the specific inherent optical properties (SIOPs) of water constituents is fundamental to remote sensing applications. Therefore, this paper presents the absorption properties of phytoplankton, gelbstoff and tripton for three small, optically-diverse South African inland waters. The three reservoirs, Hartbeespoort, Loskop and Theewaterskloof, are challenging for remote sensing, due to differences in phytoplankton assemblage and the considerable range of constituent concentrations. Relationships between the absorption properties and biogeophysical parameters, chlorophyll-a (chl-a), TChl (chl-a plus phaeopigments), seston, minerals and tripton, are established. The value determined for the mass-specific tripton absorption coefficient ∗ 2 −1 at 442 nm, atr(442), ranges from 0.024 to 0.263 m ·g . The value of the TChl-specific ∗ phytoplankton absorption coefficient (aφ) was strongly influenced by phytoplankton species, ∗ 2 −1 size, accessory pigmentation and biomass.
    [Show full text]
  • Pigment Signatures of Phytoplankton Communities in the Beaufort Sea
    Biogeosciences, 12, 991–1006, 2015 www.biogeosciences.net/12/991/2015/ doi:10.5194/bg-12-991-2015 © Author(s) 2015. CC Attribution 3.0 License. Pigment signatures of phytoplankton communities in the Beaufort Sea P. Coupel1, A. Matsuoka1, D. Ruiz-Pino2, M. Gosselin3, D. Marie4, J.-É. Tremblay1, and M. Babin1 1Joint International ULaval-CNRS Laboratory Takuvik, Québec-Océan, Département de Biologie, Université Laval, Québec, Québec G1V 0A6, Canada 2Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN), UPMC, CNRS, UMR 7159, Paris, France 3Institut des sciences de la mer de Rimouski (ISMER), Université du Québec à Rimouski, 310 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada 4Station Biologique, CNRS, UMR 7144, INSU et Université Pierre et Marie Curie, Place George Teissier, 29680 Roscoff, France Correspondence to: P. Coupel ([email protected]) Received: 11 August 2014 – Published in Biogeosciences Discuss.: 13 October 2014 Revised: 15 December 2014 – Accepted: 30 December 2014 – Published: 17 February 2015 Abstract. Phytoplankton are expected to respond to recent potentially leads to incorrect group assignments and some environmental changes of the Arctic Ocean. In terms of misinterpretation of CHEMTAX. Thanks to the high repro- bottom-up control, modifying the phytoplankton distribution ducibility of pigment analysis, our results can serve as a base- will ultimately affect the entire food web and carbon export. line to assess change and spatial or temporal variability in However, detecting and quantifying changes in phytoplank- several phytoplankton populations that are not affected by ton communities in the Arctic Ocean remains difficult be- these misinterpretations. cause of the lack of data and the inconsistent identification methods used.
    [Show full text]
  • Photosynthetic Action Spectra of Marine Algae*
    PHOTOSYNTHETIC ACTION SPECTRA OF MARINE ALGAE* BY F. T. HAXO~ AND L. IL BLINKS (From the Hopkins Marine Station of Stanford University, Pacific C-ro~e) (Received for publication,October 26, 1949) INTRODUC'rION Englemann (1883, 1884) showed by an ingenious, though not strictlyquanti- tative method (migration of motile bacteria to regions of higher oxygen con- centration), that various algae displayed high photosynthetic activity in spectral regions in which light absorption was due mainly to pigments other than chlorophyll. From these now classic experiments it was concluded that, in addition to chlorophyll, other characteristicpigments of blue-green, red, and brown algae participate in photosynthesis. Substantial proof of Engclmann's contention has come from the more ex- tensive and exacting studies of this problem carried out in recent years. Dutton and Manning (1941) and Wassink and Kerstcn (1946) have shown that light absorbed by fucoxanthin, the major accessory pigment of diatoms, is utilized for photosynthesis with about the same efficiencyas that absorbed by chloro- phyll. However, the carotenoids of some other plants (which lack the fucoxan- thin protein) appear to be relativelyinactive; this situation has been reported for purple bacteria (French, 1937), Chlorella (Emerson and Lewis, 1943), and Chroococcus (Emerson and Lewis, 1942). In the latter blue-green alga the de- tailed study by these workers of quantum yield throughout the spectrum pro- vided conclusive proof that another pigment, the water-soluble chromoprotein phycocyanin, is an efficientparticipant in photosynthesis. The red algae, being in most cases macroscopic in form and marine in habitat, have not been studied by the quantitative methods applied to the aforemen- tioned unicellularalgae (cf.,however, the manometric studies of Emerson and Grcen, 1934, on Gigartina).
    [Show full text]
  • EBS 566/555 Lecture 14: Phytoplankton Functional
    EBS 566/555 3/3/2010 Lecture 15 Blooms, primary production and types of phytoplankton (Ch 2, 3) Topics – Finish blooms – Major taxa of phytoplankton – How to measure phytoplankton – Primary production http://cmore.soest.hawaii.edu EBS566/666-Lecture 13 1 Alternatives to the Spring Bloom • Polar and tropical seas • Shallow water case: stratification not important for bloom initiation, only light is important • Estuaries (Cloern and Jassby 2008, 2009) • Extremely oligotrophic regions • Iron limitation (e.g. subarctic North Pacific) – But also applies to spring bloom! • Grazing regime • Upwelling systems (coastal, equatorial) EBS566/666-Lecture 13 2 Global comparison of phytoplankton biomass In South Pacific Gyre, chl a is highest in winter compared to summer Green = chl a Red = mixed layer depth (determined from Argo float) Claustre, unpubl. EBS566/666-Lecture 13 4 Annually averaged chl a HNLC HNLC HNLC EBS566/666-Lecture 13 5 Fate of bloom phytoplankton • Shallow decomposition ( microbial loop, regeneration) • Export – To deep ocean – Burial in sediments ( sedimentary record) • Grazing – Mesozooplankton – Microzooplankton – Excretion regenerated nutrients EBS566/666-Lecture 13 6 We can estimate algal biomass using the photosynthetic pigment, chlorophyll a micro.magnet.fsu.edu http://www.agen.ufl.edu hypnea.botany.uwc.ac.za left: Chloroplast of Chlamydomonas, a unicellular green alga. Note the chloroplast (Chl) with stacked thylakoids, and starch (s). TEM image by Richard Pienaar stroma grana lamellae/stroma thylakoids The ‘Z’ scheme Non-cyclic
    [Show full text]
  • Environmental Chemistry I Lab. 5. the Impact of Acid Precipitation On
    Environmental Chemistry I Lab. 5. The impact of acid precipitation on vegetation EPM sem. PHOTOSYNTHETIC PIGMENTS Pigments are chemical compounds which reflect only certain wavelengths of visible light. This makes them appear colorful. Flowers, corals, and even animal skin contain pigments which give them their colors. More important than their reflection of light is the ability of pigments to absorb certain wavelengths. Because they interact with light to absorb only certain wavelengths, pigments are useful to plants and other autotrophs – organisms which make their own food using photosynthesis. In plants, algae, and cyanobacteria, pigments are the means by which the energy of sunlight is captured for photosynthesis. However, since each pigment reacts with only a narrow range of the spectrum, there is usually a need to produce several kinds of pigments, each of a different color, to capture more of the sun's energy. There are three basic classes of pigments: Chlorophylls are greenish pigments which contain a porphyrin ring. This is a stable ring- shaped molecule around which electrons are free to migrate. Because the electrons move freely, the ring has the potential to gain or lose electrons easily, and thus the potential to provide energized electrons to other molecules. This is the fundamental process by which chlorophyll "captures" the energy of sunlight. Carotenoids are usually red, orange, or yellow pigments, and include the familiar compound carotene, which gives carrots their color. These compounds are composed of two small six-carbon rings connected by a "chain" of carbon atoms. As a result, they do not dissolve in water, and must be attached to membranes within the cell.
    [Show full text]
  • Dyes and Colorants from Algae
    Dyes and Colorants from Algae List of Contents • Introduction • Common Algal Pigments o Phycoerythrin o Phycocyanin o Beta-carotene o Chlorophyll o Fucoxanthin • Role of Diatoms as Algal Pigments • Extraction of Algal Pigments • Application • Conclusion Introduction Dyes and Colorants from natural sources are gaining importance mainly due to health and environmental issues. Algae contain a wide range of photosynthetic pigments. Three major classes of photosynthetic pigments are chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins. Phycocyanin and phycoerythrin belong to the major class of phycobilins photosynthetic pigment while fucoxanthin and peridinin belong to carotenoid group of photosynthetic pigment. The table below elucidates the different types of algae and the major pigment they contain. Division Common Name Major Accessory Pigment Chlorophyta Green algae chlorophyll b Euglenophyta Euglenoids chlorophyll b Phaeophyta Brown algae Chlorophyll c1 + c2, fucoxanthin Chrysophyta Yellow-brown or golden- chlorophyll c1 + c2, brown algae fucoxanthin Pyrrhophyta Dinoflagellates chlorophyll c2, peridinin Cryptophyta Cryptomonads chlorophyll c2, phycobilins Rhodophyta Red algae phycoerythrin, phycocyanin Cyanophyta Blue-green algae phycocyanin, phycoerythrin Source : http://www.clarku.edu/faculty/robertson/Laboratory%20Methods/Pigments.html The advantages of using algae as the source of dyes and food colorants are 1. Nutritional Value : Most of the pigments have high nutritional value unlike their synthetic counterparts. 2. Eco-friendliness : The process of production of natural dyes from algae does not involve the usage of harmful and/or polluting chemicals. The majority of these effluents are biodegradable and can also be reused as fodder, bioplastics etc. 3. Non-Toxicity and Non-Carcinogenicity : Pigments derived from algae have been certified as safe for usage as food colorants.
    [Show full text]
  • Figures 1.1Bi, 1.1Bl, 1.1Bm, 1.1Bn, and 1.56)
    1 Euglenozoa—Euglenophyceae Euglenophyceae include mostly unicellular flagellates, although colonial species are common (Figures 1.1bi, 1.1bl, 1.1bm, 1.1bn, and 1.56). They are widely distributed, occurring in freshwater, but also brackish and marine waters, most soils and mud. They are especially abundant in highly heterotrophic environments. The flagella arise from the bottom of a cavity called reservoir, located in the anterior end of the cell. Cells can also ooze their way through mud or sand by a process known as metaboly, a series of flowing movements made possible by the presence of the pellicle, a proteinaceous wall that lies inside the cytoplasm. The pellicle can have a spiral construction and can be ornamented. The members of this division share their pigmentation with prochlorophytes, green algae, and land plants, since they have chlorophylls a and b, β- and γ-carotenes, and xanthins. However, plastids could be colorless or absent in some species. As in the Dinophyceae, the chloroplast envelope consists of three membranes. Within the chloroplasts, the thylakoids are usually in groups of 3, without a girdle lamella; pyrenoids may be present. The chloroplast DNA occurs 1 2 as a fine skein of tiny granules. The photoreceptive system consisting of an orange eyespot located free in the cytoplasm and the true photoreceptor located at the base of the flagellum can be considered unique among unicellular algae. The reserve polysaccharide is paramylon, β-1,3-glucan stored in granules scattered inside the cytoplasm, and not in the chloroplasts such as the starch of the Chlorophyta. Though possessing chlorophylls, these algae are not photoautotrophic but rather obligate mixotrophic, because they require one or more vitamins of the B group.
    [Show full text]
  • The Role of Chlorophyll in Photosynthesis
    The Role of Chlorophyll in Photosynthesis The pigments of plants trap light energy and store it as chemical energy_ They do this by catalyzing an oxidation-reduction process in which hydrogen atoms are boosted from water to organic m,atter by Eugene t Rabinowitch and Govindjee y effort to understand the basis of multiplied by the molecular weight of J. A. Bassham; SCIENTIFIC AMERICAN, life on this planet must always the substances in question-in this case June, 1962]. The fog has also thinned X come back to photosynthesis: the carbohydrate and oxygen, out in other areas, and the day when process that enables plants to grow by When one of us first summarized the the entire sequence of physical and utilizing carbon dioxide (C02), water state of knowledge of photosynthesis 17 chemical events in photosynthesis will (H20) and a tiny amount of minerals, years ago, the whole process was still be well understood seems much closer. Photosynthesis is the one large-scale heavily shrouded in fog [see "Photo­ The photosynthetic process apparent­ process that converts simple, stable, in­ synthesis," by Eugene L Rabinowitch; ly consists of three main stages: (1) the organic compounds into the energy-rich SCIENTIFIC AMERICAN, August, 1958]. removal of hydrogen atoms from water combination of organic matter and oxy­ Five years later investigation had pene­ and the production of oxygen molecules; gen and thereby makes abundant life on b'ated the mists sufficiently to disclose (2) the transfer of the hydrogen atoms earth possible, Photosynthesis is the some of the main features of the proc­ from an intermediate compound in the source of all living matter on earth, and ess [see "Progress in Photosynthesis," first stage to one in the third stage, and of all biological energy, by Eugene L Rabinowitch; SCIENTIFIC (3) the use of the hydrogen atoms to The overall reaction of photosynthesis AMERICAU, November, 1953].
    [Show full text]
  • Chapter 2828 Protists
    ChapterChapter 2828 Protists PowerPoint® Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Overview: Living Small • Even a low-power microscope can reveal a great variety of organisms in a drop of pond water • Protist is the informal name of the kingdom of mostly unicellular eukaryotes • Advances in eukaryotic systematics have caused the classification of protists to change significantly • Protists constitute a paraphyletic group, and Protista is no longer valid as a kingdom Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig. 28-01 1 µm Concept 28.1: Most eukaryotes are single-celled organisms • Protists are eukaryotes and thus have organelles and are more complex than prokaryotes • Most protists are unicellular, but there are some colonial and multicellular species Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Structural and Functional Diversity in Protists • Protists exhibit more structural and functional diversity than any other group of eukaryotes • Single-celled protists can be very complex, as all biological functions are carried out by organelles in each individual cell Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings • Protists, the most nutritionally diverse of all eukaryotes, include: – Photoautotrophs, which contain chloroplasts –
    [Show full text]
  • Hyperspectral Remote Sensing of Cyanobacteria in Turbid Productive Water Using Optically Active Pigments, Chlorophyll a and Phycocyanin
    Remote Sensing of Environment 112 (2008) 4009–4019 Contents lists available at ScienceDirect Remote Sensing of Environment journal homepage: www.elsevier.com/locate/rse Hyperspectral remote sensing of cyanobacteria in turbid productive water using optically active pigments, chlorophyll a and phycocyanin Kaylan Randolph a,d,⁎, Jeff Wilson a, Lenore Tedesco b,d, Lin Li b, D. Lani Pascual d, Emmanuel Soyeux c a Department of Geography, Indiana University–Purdue University, Indianapolis, United States b Department of Earth Sciences, Indiana University–Purdue University, Indianapolis, United States c Veolia Environnement, France d Center for Earth and Environmental Science, Indiana University–Purdue University, Indianapolis, United States ARTICLE INFO ABSTRACT Article history: Nuisance blue-green algal blooms contribute to aesthetic degradation of water resources by means of Received 26 March 2007 accelerated eutrophication, taste and odor problems, and the production of toxins that can have serious Received in revised form 19 May 2008 adverse human health effects. Current field-based methods for detecting blooms are costly and time Accepted 5 June 2008 consuming, delaying management decisions. Methods have been developed for estimating phycocyanin concentration, the accessory pigment unique to freshwater blue-green algae, in productive inland water. By Keywords: employing the known optical properties of phycocyanin, researchers have evaluated the utility of field- Hyperspectral collected spectral response patterns for determining concentrations of phycocyanin pigments and ultimately Remote sensing fi Cyanobacteria blue-green algal abundance. The purpose of this research was to evaluate eld spectroscopy as a rapid Phycocyanin cyanobacteria bloom assessment method. In-situ field reflectance spectra were collected at 54 sampling sites Chlorophyll a on two turbid reservoirs on September 6th and 7th in Indianapolis, Indiana using ASD Fieldspec (UV/VNIR) Blue-green algae spectroradiometers.
    [Show full text]
  • RESEARCH INTERESTS Dr
    RESEARCH INTERESTS Dr. J. William Louda [email protected] My research interests center around the so-called lipophilic pigments. Specifically, these are the chlorophylls, chlorophyll derivatives, carotenoids, certain polyaromatic hydrocarbons (perylene) and a dimeric indole-phenol (scytonemin). For the past two decades I have also devoted much time and energy to the investigation of environmental water quality, namely primary plant nutrients (nitrogen, phosphorus, iron etc.). This facet of my studies includes investigating the impact of phosphorus and nitrogen pollution from the indiscriminant over-use of equestrian wastes in agri-business. Namely horse manure on nurseries with runoff into the canals and other surface waters of south Florida. Lately (2015+) this also includes investigating all sources of nutrient pollution as it applies to harmful algal / cyanobacterial blooms in Lake Okeechobee and all waters downstream. An examination of my vita reveals that I have had certain periods of research. The early seventies included studies on de novo carotenogenesis in various species of the genus Mycobacterium. Several of the mycobacteria are photochromogenic, producing pigments only when induced to do so by light – and light of the proper wavelength. This was my introduction into the fascinating world of biological pigments. I extended my interest in carotenoids with my master’s thesis topic – carotenoids metabolism in Crustacea, namely the blue-crab (Callinectes sapidus Rathbun 1895). From the late seventies through the early nineties, I was involved in organic geochemical studies of deep sea, lake and coastal sediments as well as sediment traps and selected experimental (senescence / death) studies. These 1 investigations traced chlorophyll and its derivatives from living biota into the geosphere to eventual destruction (recycle) or preservation as a variety of free-base and metallo- geoporphyrins, notably in oil shales and petroleum crudes.
    [Show full text]