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Plant Biology |
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... BOTANY IS A BROAD FIELD · Many kinds of plant biologists · Botanists interested in ecology study interactions of plants with other organisms and the environment. ... · Many work in the field, to study patterns with the whole plant. ... · They may even study how genetic information in DNA controls plant development. ... BOTANY HELPS SOCIETY · The results of botanical research increase and improve our supply of medicines, foods, fibers, building materials, and other plant products. ... · Public health and environmental protection professionals depend on their understanding of plant science to help solve pollution problems. ... Many plant species are especially sensitive to certain pollutants. ... · By using plant tissue culture, botanists can grow entire plants from single cells. · This has exciting potential in biotechnology, horticulture, forestry, and plant pathology: EX-The American chestnut was once a widespread tree in our eastern forests. ... EX-We use some plant chemicals to treat certain types of cancer. ... · Plant taxonomists and plant ecologists work to identify and understand new plant species, especially in such biologically rich areas as tropical rain forests. ... · Perhaps a plant as yet undiscovered will become an important food crop. ... · Marketing or administration of plant-related industries such as pharmaceutical companies, seed companies, biotechnology firms, scientific publishers and biological supply houses. ... · Service in public affairs, at the community and national levels, is an increasingly important role for plant biologists. ... · Glucose molecules can be linked to form starch, a storage product (starch is plant fat). ... PLANT ANATOMY (PARTS) Vegetative Structures Roots · Absorptive structures of minerals & water; usually underground Shoot · Conductive structures; gets minerals & water to leaves and glucose to roots. ... NUTRITION · Basic nutritional needs of humans are to supply energy & raw materials for various activities that occur in body FIVE TYPES OF NUTRIENTS 1 Macro-nutrients (big) · Carbohydrates, proteins, & fats 2 Micro-nutrients (small) · Vitamins & minerals 3 Proteins · Provide raw material for synthesis of essential metabolites, growth and tissue maintenance 4 Sugars (monosaccharides, disaccharides) Monosaccharides · Means “one sugar” · Most abundant = Glucose · During digestion many carbohydrates (CHO) are broken down or converted to glucose (C6H12O6) · Transported by blood to all cells in body · Within cells, use the process of cellular respiration to metabolize glucose to produce energy = ATP [Fructose also common in fruits] Disaccharides · Means “two sugars” · Table sugar = sucrose · Others are lactose & maltose 5 Complex carbohydrates (polysaccharides) Polysaccharides · Means ”many sugars” · Hundreds to thousands of individual sugars Starch · Storage form of glucose found in plants · Abundant in seeds, some fruits, tubers & taproots Glycogen · Body storage form of glucose—animal fat · Can only store a small amount = one days worth of energy Fiber · Another type of polysaccharide · From plants, not-digestible fruits, vegetables, seeds, and whole grains Cellulose, Lignin, Pectin, & Gums · Mainly found in plant walls; not digestible by humans · Humans need the help of intestinal bacteria to digest these · Oat bran & pectin are thought to lower cholesterol · Wheat bran speeds passage through the colon (laxative) PROPAGATION DEMONSTRATION Hand out Asexual propagation is possible because each cell of the plant contains all the genes necessary for growth and development and, during the cell division (Mitosis) that occurs during growth and regeneration, the genes are replicated in the daughter cells. Mitosis occurs in specific growing points or areas of the plant to produce growth. ... Mitosis also occurs when callus forms on a wounded plant part and when new growing points are initiated on root and stem pieces. ... The capacity for regenerating the entire plant structure, a property of essentially all the plants living cells, is dependent on two fundamental characteristics of plant cells. One is totipotency, which means that each living plant cell contains the genetic information necessary for reconstituting all the plant parts and functions. ... · Changes in plant characteristics i. ... Vegetables · In botanical terms some vegetables are fruits EX- Tomato, squash · True vegetables come from "vegetative" parts of the plant EX- Carrot · Thus. ... · For dispersal - plant puts few resources into fruit - sugar is immediate result of photosynthesis so less expense. ... As the fruit gets more red, the acidity decreases and the sugars and vitamin C increases, flavor develops and fruit softens At same time respiration peaks and ethylene increase Ethylene = gaseous plant hormone mainly involved in fruit ripening. ... Cereal Grains & Forage Grasses Chapter 6 Grasses = wheat, corn, rice, barley, sorghum, oats, millet & rye all among top 25 food crops Grass family = Poaceae = most diverse plant family in terms of number of species (8500) and habitats in which the plants grow Flowering plants can be split into 2 categories: Monocots & Dicots Seed germination Members of the grass family are monocots with herbaceous (no woody parts) growth, linear leaves with parallel venation & flower parts in 3s (ex. ... US major crop in CA, AK, TX, LA, MS Upland rice (not flooded but needs high rainfall); Brazil largest producer Paddy rice (grown in flooded areas) Azolla (water fern) & Anabaena (cyanobacteria) -Symbiosis = "green manure" Short grain (sticky) Long grain (not sticky) Wild rice; not related; New World species Rye - low gluten content needs to be mixed with white flour Oats -traditionally for horses Oat bran - reduces cholesterol HDL Barley - animal feed, beer brewing, in soup Sorghum & Millet - not used in US but important in other parts of world US - bird seed Forage grass - planted for animals; not so much the seeds but whole plant used; example = hay. ... Incomplete proteins Complete proteins contain all the amino acids needed to build human proteins (meat) Incomplete proteins are missing at least one amino acid needed for humans (plant protein) Beans & Corn example of two incompletes making a complete Legumes are the only plants able to form a symbiosis with Rhizobium (N2 fixing bacterium) in Root Nodules Good rotational crops because they put nitrogen back into the soil if the plants are plowed under Beans - many varieties of the same species; good example of selection for different traits Peanuts Native to South America Development of fruits underground George Washington Carver Products = peanut butter, peanut oil, cosmetics, feed for livestock Soybeans Native to northern China dried or fresh - not very digestible (trypsin) products - soy milk, okara, tofu, soy sauce process of making soy milk, okara & tofu dried beans soaked in H2O, crushed & heated 1. ... grasses Structure of roots seen in the root crop - Carrot Vascular system in the middle (xylem & phloem) Cortex -Epidermis -Root Hairs -Botanically we think of foods that come from the vegetative part of a plant ie. ... Carrots are part of a biennial plant = two years to complete the life cycle. The first year the plant has lots of leaves for photosynthesis and stores large amounts of food in the root then the second year it uses this surplus to produce flowers. ... Later, Dutch plant breeders developed a deep orange carrot that is the ancestor to all modern day carrots we eat. ... Starch from Vegetative Plant Parts Grains contain starch but also other parts - stems & roots Most starch crops = modified stems & roots Stolon or runners- above ground stem - strawberries can multiply without sexual reproduction Rhizome - (underground stems) - buds give rise to new plants ginger Tuber - (enlarged storage tips of rhizome) potato eyes = buds Corms - storage of food in underground stems; crocus, gladiolus Bulbs -monocots, modified stems fleshy & papery leaves, garlic, onion, tulips White potato Solanum tuberosum Originated on the Andean plateau 8,000 years ago Actually found wild from South America through Southern US Spanish brought back to Europe; use for animal food; 18 th century for humans Poisonous relatives; tuber only safe part to eat Irish Famine relied on a single crop; genetically identical; caused by Phytophthora infestans = fungus late blight kills the leaves and stems = tuber growth stopped. ... Spices, Herbs and Perfumes Chapter 9 Chemistry Plants chosen for herbs, spices & perfumes have oils that impart the flavor & smell The oils are termed essential or volatile - which means they diffuse readily in air Oils are produced in specialized cells or glands and can be in any part of the plant Why would plants produce these? ... Vanilla - Only crop from the orchid family (exclusive of growing for arrangements) The spice comes from the fruit (pod) of the plant Flavor is brought out through a series of steps involving "sweating" the pods "real vanilla specks" are the tiny seeds Vanilla sugar -2. ... Allspice - dried green berries; tastes like combination of cinnamon, cloves & nutmeg Herbs Mint Family - Basil, Mint (spearmint, peppermint), Oregano, Rosemary, Thyme, Sage Carrot Family - Parsley, Dill, Cilantro, Coriander, Anise, Cumin, Fennel, Celery, Caraway Mustard Family - Mustard (black, white seed), Horseradish Vegetable Oils & Waxes Chapter 10 Most plant oils come from the seed; in specific the embryo or germ There are two notable exceptions: olive & palm oil from fruit These oils are called fatty or nonvolatile because "greasy" as opposed to volatile oils What are vegetable oils? Acylglycerides = fatty acid & glycerol (3 carbon alcohol) oils differ in the fatty acids associated Fatty acid can be removed from the glycerol by hydrolysis (breaking apart with the addition of water) Sodium or Potassium salts of the fatty acid = soaps (primary product of plant oils) Fatty acids can be characterized as a. ... polyunsaturated All vegetable oils are a mixture of all 3 but the predominate one is used on the label Fatty acids most commonly found in vegetable oils are Oleic, Stearic & Palmitic Fatty acids can absorb or react with oxygen = change in oil sometimes refer to as rancid; to prevent use antioxidants = preservatives Nonfood Uses of Vegetable oils For soaps - use to be lard (animal fat) now mostly plant oils Unsaturated oils Important in paints and varnishes Oil based paints use a metal (previously lead) to help oxidize and form hard coating Latex paint = resins from fatty acids cleaved from vegetable oils Linoleum Started out as oxidized linseed oil mixed with cork; replaced by plastic but even this is made from polymers derived from seed oils. ... Much less health Polyunsaturated oils Linseed oil - mainly used as a water repellent on surfaces; one of the oldest crops; can be edible but it degrades quickly and better tasting oils now available; same plant as flax Tung oil - same as teak oil; poisonous so not used as a food; ingredient in India Ink Unsaturated oils Safflower oil - most unsaturated of the commonly used cooking oils; not terribly popular; highest source of linoleic acid; used in salad dressings & margarine because can take the cold; also used in paints & varnishes; remaining cake used as a high protein animal feed Soybean oil - 50% of vegetable oil used world wide comes from this plant; salad or cooking oil; whipped toppings, mixes for icings & instant cheesecakes Sunflower oil - can be mixed with diesel oil or used alone; used as a salad, cooking & commercial oil in prepared foods; other parts of the world used in paints, varnishes & synthetic resins Corn oil - by product of extracting starch; used in salad dressings & margarine; stable because contains natural antioxidants; not good for cooking because smokes Sesame oil - can be used in cooking; again cake used as feed; seeds themselves most often used "sesame seed buns" Cottonseed oil - by product of cotton industry otherwise would not be used; Crisco is from cottonseed oil = first vegetable shortening Canola oil - rising in importance as a cooking oil; historically more important as a lubricant but new processing make it good for consumption Moderately Saturated Oils Peanut oil - premium cooking oil because it does not smoke at high temp; cakes used as feed Olive oil - cooking oil; virgin comes from the first pressing (cold) subsequent pressing in heat yield less desirable oil Castor oil - medicinal in the past as a laxative; now used in paints, varnishes and cosmetics; hydrogenated oil used as a lubricant for planes and rocket engines; cakes used for fertilizer; too toxic for feed Vegetable Fats Palm & Palm kernel oil - primarily used in soaps & candles; were used in margarine & solid shortenings but health issues Coconut oil - used in margarine; saturated fat; used in shampoos, hand lotions, & suntan screens Waxes Jojoba oil - similar to sperm whale oil so renewable resource; lubricant for industrial equipment; good at penetrating skin so used in cosmetics; grows well in dry areas not suitable for other crops Bayberry wax - novelty candles Dr. ... In the US, 10% of our major medical drugs contain plant compounds as the active ingredient and more than 25% have some plant compounds or have compounds synthesized from plant compounds. ... There are four main categories of medically active plant compounds: fatty acids & essential oils; gums & resins; alkaloids; and steroids. ... Steroids have no known role in plant metabolism and may be 2º products. ... Steroids and alkaloids have strong effects on animal physiology and of the 22 drugs from angiosperms, 9 are plant steroid based while the rest are alkaloids. ... Red Clover Herbal (non-caffeinated) tea Weak flavor, mostly due to nectar in flowers Both leaves and flowers used Generally used in admixture with other herbs in teas Hyrdrogels, Elastic Latexes & Resins Chapter 11 Three products extracted or exuded from various parts of the plant and all are ‘sticky’ Discuss all three together to highlight similarities and differences Hydrogels Hydrogels = hydrocolloids = water-modifying substances including all products collected, extracted or synthesized to alter the behavior of water Example, gravy thickening; starch attached to water molecules so as to not let them move. Most common household hydrogels are starch, pectin & gelatin (from animals) 3 types of hydrogels (gums, pectins & starches) Gums Most gums come from compounds produced when the plant is wounded & these substances seal the wound All gums are polysaccharides composed of sugars other than glucose Gums are water soluble but insoluble in alcohol Gums are only partially digested by humans; inert substance in diet; good for diet food, medicines and other foods; non food uses are in paper, textile, cosmetic & petroleum industries Food Industry Gums used to texturize food, add body for better texture, stabilize emulsions, retain moisture, thicken liquids & suspend particles Example, dairy products use to disperse fat & protein evenly in a water base Gums help prevent formation of ice crystals in frozen products Sauces & syrups product thick consistency Increase shelf life of products by preventing solid particles from settling out Sprayed on powdered products so that water is not absorbed before using Use in ice cream whipped toppings, commercial frosting & cream fillings Added to sandwich spreads and processed meat to bind everything together Medicines Hold tablets together Keep suspensions smooth in liquid Used as a laxative Makes toothpaste paste a cream Makes lotions & creams smooth Industrial uses Paper industry as sizing (substances that fill in the pores of paper to make it smooth) Garment industry as sizing (washes out easily; not digestible) Gums on envelopes or stamps Petroleum industry 2 uses 1. ... Sources of Vegetable Gums Exudate Gums Most widely used exudate gum is gum Arabic exuded from wounded trees of Acacia; used since Egyptian times From Africa but sold by Arabs to Europe - that where it got its name; 90% of world supply comes from wild trees that are slashed or punctured to induce a wound reaction; people collect the dried globs of gum; Things that have it - beer (the lacy foam is from gum used to stabilize the foam); postage stamps; hand lotion, liquid soaps Other gums as well used in a variety of manners already described Extractive Gums Come from endosperm of some legume seeds or extracted from the wood Important seed gums are locust gum & guar gum Locust bean gum = carob gum mummy wrappings & chocolate substitute (fruit mesocarp) Endosperm of seed ground into powder Used in ice creams, salad dressings, & pie fillings Guar gum - also from endosperm; shrub used for cover in grazing; TX & Oklahoma main growers Used in paper industry; petroleum and fire hoses for less friction Semisynthetic Gums Semisynthetic cellulose (from plant cell wall) gum - most important in detergents as a whitener and brightener; part of the dirt that is rinsed off the clothing can re-attach during the spin cycle; the gum binds to the dirt and prevents it from re-attaching Important in paper industry to replace starch and used in all other ways mentioned above for foods Pectin Special group of plant polysaccharides which form a gel under certain circumstances Non-digestible to humans but gut bacteria use them as a Carbohydrate source. Mainly come from fruit peels 75% of pectin used in Jams & jellies; some fruits have enough naturally Small amount used in Kaopectate "coat & sooth" Most pectin comes from apple peels, a byproduct of the apple juice industry; others used are oranges, grapefruit & lemon again a byproduct Starch Extracted from seeds & roots Crops used are corn, wheat & sorghum Starch is extracted and used in powdered form (corn starch) Cool water needed to disperse before making gravy; in hot water becomes gelatinous mess Paper industry not a good idea because of environmental problems Food industry as a thickener Industrial - glue & "starching shirts Elastic Latexes & Resins Chapter 11 Rubber-Producing Latex Latex = any mixture of organic compounds produced in laticifers Laticifers are networks of cells throughout plant organs Only known in flowering plants; occur throughout the kingdom Latex may be elastic or not; example of not = opium poppy Function of latex in plants is unknown but may be anti-herbivore or byproduct or reserves for future compounds Story of Rubber Elastic latex is commonly referred to as "rubber" phrase coined in 1770 because could rub errors from a page Discovered by many native people around the world simultaneously & used in various manners Example - Amazon natives dipped their feet in the rubber latex and held them over the fire to "cure" or harden the rubber to their feet = "early sneakers" Spanish explorers started to dip their hats & coat in it for waterproofing 1823 Sir Charles Macintosh discovered that it is soluble in hexane Important because could ship and re-dissolve to use off site Macintosh rain slicker named for him Problems - cracked in cold weather & got sticky in hot weather 1839 Charles Goodyear discovers vulcanization found by accident when spilled a sulfur compound and rubber on a hot stove hence the name after Vulcan god of fire Vulcanization = adding sulfur with lead oxide to rubber = cross linkage of molecules resulting in improved elasticity and impervious to weather >1880 all rubber was extracted from wild trees by natives trees slashed diagonally across bark and cups to catch latex coagulated in smoke house to balls and shipped that way 1876 seeds taken to Kew in London and then to Southeast Asia Couldnt grow in Amazon basin because of leaf blight By WWII 90% of rubber was from Asian plantations WWII rubber supply cut off USA starts experimenting for new rubber sources Discovery of synthetic process End of WWII 75% of rubber synthetic Synthetics come from petroleum Problem with depleting source but will not find alternatives until cost effective May go back to natural rubber being primary source One might think that synthetic is superior quality - NOT Radial tires need a large amount of natural rubber because of its superior resilience Because of renewed interest have looked to other natural sources Gutta-percha rubber - disintegrates in air but is a good insulator and resistant to sea water used in golf balls & underwater cables Story of Chewing Gum "Chiclets" = Chicle, milky-white exudate from the sapodilla tree Mexican politician Santa Anna wanted to make industrial rubber Inventor Thomas Adams unsuccessful but did make gum because remembered that natives chewed it Resins Actively synthesized by plants produced in special canals or ducts Deter herbivores and some have antibacterial properties Ancient use of resins is incense sometime mixed with gums volatile oils released in smoke ie Frankincense and myrrh Another resin is lacquer Pine resin is very important and known as pitch, turpentine & rosin Rosin for baseball, string instruments, sealant, varnishes & paper coatings Turpentine - important solvent & cleaning agent for oil based paint, but also as a starting material for further synthesis of deodorants, shaving lotions & some medicines Most resins synthetic today Only jewel of plant origin – AMBER Medicinal Plants Chapter 12 History Egyptians & Chinese 4,000 years ago Greeks & Romans Hippocrates Dioscorides - De Materia Medica Many Remedies Lost-Example - giant fennel Dark Ages = no new discoveries Renaissance = Age of Herbals -books about medicinal plants Doctrine of Signatures - medicinal uses of plants correspond to “signatures” of human anatomy Examples - Blood Root for blood diseases; Walnut for brain afflictions Modern Prescription Drugs Many purified extracts from plants (~25%) Many based on synthetic compounds first derived from plants Modern Herbal Medicine 75-90% of rural population world wide use it China - leader with plantations, training of doctors, research programs Chinese Apothecary India - popular because people have faith & affordable Renewed interest world wide in indigenous medicine especially tropical rain forest Belize - Terra Nova Forest Reserve Active Compounds in Plants Alkaloids Common characteristics 1. |
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Title: Plant Biology
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