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The Biology of Chemical Defense

The Biology of Chemical Defense. Objectives. Explain why animals use chemicals for defense Describe how do organisms get these chemicals Explain how the blue-ringed octopus uses its neurotoxin? How does the neurotoxin work? Understand symbiotic relationships

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The Biology of Chemical Defense

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  1. The Biology of Chemical Defense

  2. Objectives • Explain why animals use chemicals for defense • Describe how do organisms get these chemicals • Explain how the blue-ringed octopus uses its neurotoxin? How does the neurotoxin work? • Understand symbiotic relationships • Explain how whip scorpions are protected from their chemical defense • Understand pheromones • Know the 3 groups of aniherbivory compounds • Understand how alkaloids affect organisms • Explain how non protein amino acids kill organisms • Give examples of human uses for chemical defense

  3. Key Terms • Neurotoxin • Pheromone • Aposematic • Ion Channel • Symbiosis • Acetic acid • Fatty Acid

  4. How do most animals defend themselves? • Large teeth (shark) • Large size (elephant) • Sharp claws (tiger) • Fast speed (antelope) • Excellent camouflage (chameleon) • What if you don’t have any of these?

  5. Chemical Defense! • Some animals and plants use chemistry! • They synthesize the chemicals or • They accrue the chemicals from their diet • Many organisms that use chemical defenses are brightly colored as a warning to predators • Aposematic

  6. The Blue-Ringed Octopus • Shallow waters in Pacific Ocean • Neurotoxin from bacteria in body • Toxin injected by glands near mouth • TTX = Tetrodotoxin (also in puffer-fish) • TTX “plugs” ion channel in cells • One of the most poisonous sea animals http://www.msmr.org/documents/BFTBToxicology12.pdf

  7. Clownfish • Clownfish coexist (symbiotic relationship) with sea anemones • Sea anemones use tentacles to sting its prey • Why don’t they sting the clownfish? • Clownfish have evolved a protective chemical layer of mucus • Sea anemone and clownfish acclimate to each other http://en.wikipedia.org/wiki/File:Anemone_purple_anemonefish.jpg

  8. Whip Scorpion • Sprays defensive chemicals at enemies • Acetic acid from a gland in the tail • How does it protect itself? • Exoskeleton lined with protective chemicals (fatty acids) that act as solvents if spray gets on the whip scorpion http://en.wikipedia.org/wiki/File:Whipscorpion.jpg

  9. Asian Giant Hornet • World’s largest Hornet • Found in Asia • Kill more people than snakes in Japan • Pheromone used for alarm • Alarm pheromone can be used when nest is under attack • One scout hornet marks a target with the alarm pheromone • Remaining hornets aggressively attack the target http://www.naturenet.net/blogs/media/mandarinia2.jpg http://en.wikipedia.org/wiki/File:Vespa_mandarinia.jpg

  10. National Geographic Video:“Hornets from Hell”http://www.youtube.com/watch?v=DcZCttPGyJ0

  11. Plants • Plants have developed chemicals to serve as defenses against herbivores and other dangerous organisms • These compounds are known as antiherbivory compounds • Classified into three groups: • Nitrogen Compounds • Terpenoids • Phenolics

  12. Classification of Antiherbivory Compounds

  13. Alkaloids Nicotine 3-D • Alkaloids derived from amino acids : • Ornithine • Lysine • Phenylalanine • Over 3000+ known • Nicotine • Caffeine • Effects: • Enzymes • Membranes • Nucleic acids • Nerve induction http://upload.wikimedia.org/wikipedia/commons/4/43/Nicotine-3D-vdW.png Nicotine http://upload.wikimedia.org/wikipedia/commons/c/c7/Nicotine-2D-skeletal.png

  14. Non-protein amino acids Canavanine • Simplest and most widely present compound • 300+ known • Usually found in seeds • May be directly toxic or anti-metabolites. • Resemble amino acids, these compounds are mistakenly incorporated into protein synthesis • Produce defective enzymes and kill the organism http://upload.wikimedia.org/wikipedia/commons/f/f9/Canavanine.png Arginine http://upload.wikimedia.org/wikipedia/commons/f/f4/Arginin_-_Arginine.svg

  15. Terpenes • Dimers, or combinations of a 5 carbon precursor called isoprene. • 10,000+ known • Diterpenes are made of 3 to 4 isoprenes: • Poison plant resins • Glycosides: • Monarch butterflies store the glycosides they eat from plants to deter birds • Predators spit out the butterflies and avoid them in the future. http://www.nature.com/nchembio/journal/v3/n7/images/nchembio.2007.5-F4.jpg

  16. Phenols Lignin • Contain a fully saturated 6 carbon ring linked to an oxygen • Produce pigments • Inhibit microorganisms and seed germination • Lignin fortify and strengthen plant walls • Act as antioxidants or free radical receptors • Incredible medicinal value

  17. Wild Tobacco Plant • Chemical signal to lure predators to eat leaf-eating insects • A chemical SOS • Hawkmoth caterpillars hatch they feed on its leaves • Leaf-chewing by the caterpillars induces chemical release in tobacco • Chemicals help predators zero in on the Hawkmoth • When Hakwmoth detact chemical, they avoid the plant • Predators are attracted and egg-laying moths are repelled http://www.mpg.de/english/illustrationsDocumentation/documentation/pressReleases/2001/news0103_bild1.jpg

  18. Human Chemical Defense? • We use chemicals too • Pharmaceuticals • taxol • Insecticides • nicotine • Pepper “OC” spray • "Oleoresin Capsicum” • Produced from chilies and peppers • Non-lethal • Irritant to eyes http://www.defence.gov.au/Army/8_12mdm/images/101%20Solomons%20(4).jpg

  19. Summary • Why do animals use chemicals for defense? • How do organisms get these chemicals? • How the blue-ringed octopus uses its neurotoxin? • How does TTX work? • Why don’t sea anemones sting clownfish? • How does the whip scorpion use chemicals to protect itself? • What is an alarm pheromone? • What are the 3 groups of aniherbivory compounds? • What effect do alkaloids have on organisms? • How do non protein amino acids kill organisms? • How do terpenes protect monarch butterflies? • Identify human uses of chemical defenses?

  20. Questions?

  21. References • Anonymous. 1999. Biochemical defenses: secondary metabolites: Antiherbivory Biochemicals. [Online]; [about 8 screens]. <http://www2.mcdaniel.edu/Biology/botf99/herbnew/aprodbc.htm> • Anonymous. 2002. Toxicology. Breakfast for the Brain. [Online]; [about 2 screens]. <http://www.msmr.org/documents/BFTBToxicology12.pdf> • Caldwell, R. 2009. What makes blue-rings so deadly? Blue-ringed octopus' have tetrodotoxin. The Cephalopod Page. [Online]; [about 2 screens]. <http://www.thecephalopodpage.org/bluering2.php> • Yotsu-Yamashitaa, M., D. Mebsb, and W. Flachsenbergerc. 2007. Distribution of tetrodotoxin in the body of the blue-ringed octopus (Hapalochlaena maculosa). Toxicon. 49(3): 410–412. <http://www.sciencedirect.com.proxy-um.researchport.umd.edu/science?_ob=MImg&_imagekey=B6TCS-4M6RXH6-1-1&_cdi=5178&_user=961305&_orig=browse&_coverDate=03%2F01%2F2007&_sk=999509996&view=c&wchp=dGLbVlb-zSkzS&md5=eecb7d0132dcb1749a0f6498699c314a&ie=/sdarticle.pdf>

  22. References (1 of 3) • Fautin, D. and G. Allen. 1992. Field Guide to Anemone Fishes and Their Host Sea Anemones. [Online]; [about 4 screens]. <http://www.nhm.ku.edu/inverts/ebooks/intro.html> • Anonymous. 2008. Monterey Bay Aquarium. Splash Zone: Coral Reef Animals. [Online]; [one screen]. <http://www.montereybayaquarium.org/efc/efc_splash/splash_animals_clownfish.aspx> • Schmidt, J., F. Dani, G. Jones, and D. Morgan 2000. Chemistry, ontogeny, and role of pygidial gland secretions of the vinegaroon Mastigoproctus giganteus (Arachnida: Uropygi). Journal of Insect Physiology. 46(4): 443–450. <http://www.sciencedirect.com.proxy-um.researchport.umd.edu/science?_ob=ArticleURL&_udi=B6T3F-3YJYDPV-8&_user=961305&_coverDate=04%2F30%2F2000&_rdoc=9&_fmt=high&_orig=browse&_srch=doc-info(%23toc%234945%232000%23999539995%23160783%23FLA%23display%23Volume)&_cdi=4945&_sort=d&_docanchor=&_ct=25&_acct=C000049425&_version=1&_urlVersion=0&_userid=961305&md5=1026688a6374fb6606f188f84e25feec>

  23. References (2 of 3) • Handwerk, B. 2002. "Hornets From Hell" Offer Real-Life Fright. National Geographic News. [Online]; [about 3 screens]. <http://news.nationalgeographic.com/news/2002/10/1025_021025_GiantHornets.html> • MacLean, C. and E. Schmolz. 2004. Calorimetric investigations on the action of alarm pheromones in the hornet Vespa crabro. Thermochimica Acta. 414 : 71–77. <http://www.sciencedirect.com.proxy-um.researchport.umd.edu/science?_ob=MImg&_imagekey=B6THV-4BFVNKF-9-R&_cdi=5292&_user=961305&_orig=browse&_coverDate=05%2F06%2F2004&_sk=995859998&view=c&wchp=dGLzVtb-zSkWb&md5=b5c4b0b69945e4934e64e4f6e3d99ce4&ie=/sdarticle.pdf> • Matsuura, M. and S. Sakagami. 1973. A Bionomic Sketch of the giant Hornet Vespa mandarinia, a serious pest for Japanese apiculture. Journal of the Faculty of Science, Hokkaido University. Series 6, Zoology. 19(1): 125-162. <http://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/27557/1/19%281%29_P125-162.pdf>

  24. References (3 of 3) • Parry, L. 2005. Killer hornets get a taste for humans. [Online]; [about 2 screens]. Times Online. <http://www.timesonline.co.uk/tol/news/world/article582267.ece> • Voith, M. 2003. Gee, Your Hair Smells Dangerous. Volatile fragrance chemicals may attract unwanted attention from hornets and bees. [Online]. [about 2 screens]. Chemical and Engineering News. http://pubs.acs.org.proxy-um.researchport.umd.edu/cen/critter/8137hornets.html • Vesaluoma, M., L. Müller, J. Gallar, A. Lambiase, J. Moilanen, T. Hack, C. Belmonte, and T. Tervo. 2000. Effects of Oleoresin Capsicum Pepper Spray on Human Corneal Morphology and Sensitivity. Investigative Ophthalmology and Visual Science. 41:2138-2147. <http://www.iovs.org/cgi/reprint/41/8/2138>

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