RRES_150_Slides_Part_1 - Plant Science Plant Part 1 RRES...

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Unformatted text preview: Plant Science Plant Part 1 RRES 150 Class Rules Class No disturbance of class mates No Cell phones on silent, no texting Cell No eating, drinking, chewing gum or tobacco No Sign Attendance Sheet Sign Grading Scale see syllabus Grading Exam schedule see syllabus Exam Page 1 Relationship of horticulture to other agricultural disciplines and sciences sciences Page 2 Definition of Areas of Horticulture and Other Agricultural Disciplines and Agriculture - ('agri' L. = field, 'cultura' L. = cultivation) the science and technology of growing and raising plants and animals. AREAS OF AGRICULTURE AREAS 1) Forestry - the science and technology of culturing, Forestry the utilizing and improving forest tree and their products (ex. pulp, resins, oils, etc.). 2) Agronomy - the science and technology of Agronomy the culturing, utilizing and improving field crops (grain, fiber and forage crops). 3) Horticulture - ('hortus' L. = garden, 'cultura' L. = Horticulture L. cultivation) - the science, technology and art of the culturing, utilizing and improving fruit, vegetable, flowering and ornamental plants. 4) Turf Science - grasses for lawns, landscapes, sport Turf grasses facilities and golf courses (in Agronomy in many Universities). Universities). Horticulture Page 2 Classical Guidelines for Placement of a Crop in for Horticulture, Agronomy or Forestry 1) Intensity of Production 1) example strawberries vs. example cotton 2) Purpose Crop is Grown example oak or pecan trees in example forest vs. landscape 3) Tradition or Custom example sweet vs. field corn, example or tobacco or Agronomy Forestry Horticulture Horticulture Agronomy Agronomy Page 2 AREAS OF HORTICULTURE 1) Olericulture - vegetable culture Olericulture vegetable and production 2) Pomology - fruit and nut culture Pomology fruit and production 3) Ornamental Horticulture - plants plants grown for aesthetic uses, improvement of quality of life and improvement of our environment, and functional uses (ex: energy conservation). Page 2 Areas of Ornamental Horticulture Ornamental 1) Floriculture- flowering and 1) Floriculture flowering foliage plant culture and production 2) Floristry- floral design and retail Floristry floral floristry operation 3) Nursery Production - tree, shrub Nursery tree, and vine culture and production 4) Landscape Horticulture Landscape exterior and interior design, exterior construction and maintenance of landscapes landscapes Pages 3 &4 Organs and Tissue Systems in Plants Organs Organs Flower Flower Leaf Leaf Stem Stem Root Root Tissue Systems Dermal Dermal Vascular Vascular Ground or Fundamental Fundamental Pages 3 &4 1. Dermal Tissue System 1. Function: Protection from the Function: environment and water loss. environment Tissues: Tissues: a) epidermis - single layer of a) single cells on primary (herbaceous ) plant parts. plant b) periderm or bark - a corky corky tissue that replaces epidermis on secondary (woody) plant parts. (woody) Pages 3 &4 2. Vascular Tissue System Vascular Function: Conduction of water, Function: nutrients, sugars and hormones throughout the plant. throughout Tissues: a) xylem - conducts water and conducts nutrients up roots, stems and leaves. leaves. b) phloem - conducts water, sugar, conducts hormones, etc. down and up roots, stems and leaves; moves from where produced (called sources) to where needed (called sinks). sinks). Pages 3 &4 3. Ground or Fundamental Tissue System Tissue Function: Function: Storage, support, filler tissue and site of photosynthesis. and Tissues: Tissues: a) cortex - outer region of stems a) outer and roots. and b) pith - center of stems. c) mesophyll - middle of leaves and middle flower petals. Page 4 Basic Cell Types: Basic 1. Parenchyma Characteristics • • Functions • • • • Examples • • thin, non-lignified lignified primary cell walls primary intercellular space intercellular present present Filler Storage Protection Photosynthesis flesh of potato lettuce leaf Page 4 Basic Cell Types: Basic 2. Colenchyma 2. Colenchyma Characteristics • unevenly thickened, unevenly non-lignified primary non lignified cell walls cell no intercellular space no present present support in growing support tissues tissues strings in celery stalks • Functions • Examples • Basic Cell Types: Basic 3. Sclerenchyma: a. Fiber 3. Sclerenchyma b. Sclereids c. Stone cell Characteristics • Page 4 • Functions • Examples • evenly thickened, lignified evenly (tough) secondary cell walls walls dead at maturity; no dead intercellular space present intercellular support in mature tissue fiber - bamboo cane sclereid - seed coat stone cell - pear fruit • • Page 5 Cell Components: Cell Boundary Cell 1. Cell wall 1. Polysaccharide - a polymer or polymer chain of sugars chain 1. Cellulose - forms a matrix of forms microfibrils microfibrils (chains of b-1,4-linked glucose) linked 2. Hemicellulose - filler between 2. filler cellulose microfibrils microfibrils (chains of misc. sugar) 3. Pectin - cementing agent or filler; cementing high in middle lamella and fruit; (chains of galacturonic acid) (chains of galacturonic 2. Lignin - tough polymer of tough phenolic compounds; phenolic compounds; high in secondary cell wall. high 3. Protein - mainly structural mainly (most commonly hydroxyproline) most hydroxyproline Source: commons.wikimedia.org/wiki/ Image:Plant_cell_wall_diagram.svg Page 5 Cell Components Cell Cell Boundary (continued) 2. Plasmalemma or plasma or membrane - a double membrane membrane double that surrounds the cytoplasm; composed of a bilayer of bilayer of phospholipids and proteins; it is selectively permeable and regulates absorption into cells and leakage from cells. cells. 3. Plasmodesmata - tubular plasma tubular membrane extensions through cell walls that connect adjacent cells. walls Pages 5 & 6 Cell Components: Cell Interior Part 1 Cell 4. Cytoplasm - cytosol plus plus organelles; most metabolism occurs in the cytosol or its cytosol or organelles. organelles. a) Cytosol - much of the cytoplasm much is a water solution of dissolved compounds. compounds. b) Organelles - specialized specialized structures in cytoplasm, each with specific functions. with Pages 5 & 6 Cell Components: Organelles Cell 1. Nucleus - location of DNA and some of the RNA . a) chromosome - strands or coils of DNA. b) nucleolus - spherical, dense body; site of ribosome synthesis. 2. Mitochondria - major site of respiration; called the "power house" of the cell. 3. Plastid - double membrane-bound bodies for storage and photosynthesis. Pages 5 & 6 Types of Plastids Types a) leucoplast - colorless plastids. 1. amyloplast- starch storage (chains of a-1,4-linked glucose) 2. elaioplast- fat and oil storage. b) chromoplast- colored plastids for storage of carotenoids (orange and yellow pigments) c) chloroplast - green plastids that contains chlorophyll; the site of photosynthesis Pages 5 & 6 Cell Components: Cell Interior Part 2 Cell 4) Endoplasmic reticulum tubular membranes for tubular communication across the cytoplasm; site of the cytoplasm; protein & membrane synthesis synthesis 5) Ribosome - dense spheres dense of RNA; protein synthesis occurs on their surface. occurs 6) Vacuole - storage of storage organic acids, salts, anthocyanins (blue, red anthocyanins (blue, and purple pigments), metabolic wastes, enzymes and metabolites. enzymes a) tonoplast- membrane that membrane surrounds the vacuole surrounds Pages 5 & 6 Cell Components: Cell Interior Part 2 Cell 7) Golgi body or dictyosome - diskshaped membranes for shaped membrane and polysaccharide synthesis. synthesis. 8) Microbody membrane-bound bound storage bodies with various functions. 9) Microtubule - tubular tubular rods used in mitosis & cellulose orientation in cell walls cell Page 7 Genetic Basis of Life Genetic DNA (deoxyribonucleic acid) - a double double helix chain of sugar-phosphates helix phosphates (deoxyribo sugar-phosphates) connected phosphates) by nucleic acids by RNA (ribonucleic acid) - a single stranded single chain of sugar-phosphates (ribo sugarchain phosphates) containing nucleic acids. Nucleic Acids - organic acids that form the organic base pairs of DNA and single-bases base bases of RNA. of Base Pairing of Nucleic Acids: between the double strands of DNA A- T (adenine-thymine) G - C (guanine-cytosine) between DNA strands and RNA strands A - U (adenine-uracil) G - C (guanine-cytosine) Page 7 Genetic Basis of Life: Definitions Genetic Gene - a length of DNA that codes for the production length of a protein or protein subunit. - also codes for active RNAs. also RNAs Protein - a polymer or chain of amino acids. polymer Enzyme - a protein that acts as a metabolic catalyst. Page 7 Genetic Basis of Life Analogy Genetic Page 8 Meristems Meristems Meristem - discrete regions or groups of cells that possess continued cell division for the life of the plant or that organ. Page 8 Types of Growth: 1. Primary Growth Types Primary Growth - growth in length that gives rise to primary (herbaceous) tissues called the primary plant body. Two Types of Meristems Give Rise to Primary Growth: 1. apical meristem or apex the growing points located at the tips of stems and roots. 2. intercalary meristem - the growth region at the base of grass leaves that causes leaves to elongate. Page 8 Types of Growth: 2. Secondary Growth Types Secondary Growth - growth in width or diameter that gives rise to secondary (woody or corky) tissues called the secondary plant body. Secondary growth is due to lateral meristems. lateral meristem - meristematic regions along the sides of stems and roots. Two Types of Lateral Meristems Give Rise to Secondary Growth 1. vascular cambium or cambium - a sheetlike meristem between the bark and wood along the sides of woody stems and roots; it gives rise to secondary xylem (commonly called wood) on the inside and secondary phloem on the outside. 2. cork cambium or phellogen - gives rise to the periderm (commonly called bark). Page 9 Major Plant Divisions Major Gymnosperms (naked seeds) Gymnosperms Angiosperms (covered seeds) Angiosperms A gymnosperm seedling with eight cotyledons •Monocotyledons •Dicotyledons A cotyledon or "seed leaf" is a significant part of the embryo within the seed of a plant. A monocot and dicot sprouting Picture source: http://en.wikipedia.org/wiki/Cotyledon Page 9 Distinguishing Characteristics Gymnosperms (cones with naked seeds) Gymnosperms Seeds 1 to many cotyledons; no to endosperm; female gametophyte tissue present tissue No true flowers Needle-like or scale-like Ring of vascular bundles in primary Ring growth; cambium present; may have woody secondary growth have Herbaceous or woody Flowers Leaves Vascular System of Stem Growth Habit Distinguishing Characteristics Angiosperms: dicots dicots Seeds Page 9 2 cotyledons; endosperm often cotyledons; lacking lacking Flower parts in multiples Flower of 4 or 5 of Broad; net venation Ring of vascular bundles in Ring primary growth; cambium present; may have woody secondary growth woody Herbaceous or woody Flowers Leaves Vascular Vascular System System of Stem Growth Growth Habit Habit Page 9 Distinguishing Characteristics Angiosperms: monocots Angiosperms: Seeds Flowers Leaves 1 cotyledon; endosperm often present Flower parts in multiples Flower of 3 of Linear; leaf base or petiole sheathing; Linear; parallel venation parallel Vascular Scattered vascular bundles; no Vascular Scattered System cambium or secondary growth System cambium of Stem Growth Growth Habit Habit Herbaceous to wood-like (ex. palm), like but no true wood (secondary xylem) but Page 10 Function of Organs: Stems Stems 1) Support trunk, branches and stems of all plant parts 2) Conduction through phloem and xylem 3) Food storage ex. Irish potato tubers 4) Protection ex. thorns on mesquite 5) Propagation ex. bulbs, runners, rhizomes 6) Photosynthesis ex. pads (cladophylls) on cactus Page 10 Function of Organs: Leaves Function 1) Photosynthesis site where primarily occurs 2) Regulate water loss ex. by opening and closing stomata 3) Storage ex. carbohydrates and water ex. in garlic, aloe vera vera 4) Support ex. tendrils on grape 5) Protection ex. spines on cacti; bud scales 6) Attraction ex. bracts on ex. poinsettia and dogwood 7) Propagation ex. bryophyllum with ex. bryophyllum with plantlets on leaves plantlets Page 10 Functions of Organs: Roots Functions 1) Anchorage secures plant to ground or for epiphytes to branches 2) Absorption water and nutrients from soil 3) Storage ex. sweet potato, carrot or radish tuberous roots, 4) Propagation ex. dahlia or sweet potato tuberous roots, blackberry Page 11 Stem Morphology: Buds Stem bud - an underdeveloped and unelongated stem composed of a short axis with compressed internodes, a meristematic apex, and primordial leaves and/or flowers. terminal bud - a bud at the tip of a stem responsible for terminal growth. axillary bud or lateral bud - buds along side the axis of a stem; they were produced by the terminal bud during growth; once they grow out and form a lateral stem they become terminal buds of the lateral branch. flower bud - a bud containing a floral meristem which develops into flowers; usually larger than vegetative buds. Page 11 Stem Morphology Stem leaf scar - a scar marking the former point of scar attachment of a leaf or petiole to the stem. attachment node - part of stem marking the point of attachment part of leaves, flowers, fruits, buds and other stems. of internode - the part of the stem between nodes. lenticel - rough areas on stems (and some fruits, ex. rough apple) composed of loosely packed cells extending from the cortex through the ruptured epidermis; serve as "breathing pores" for gas exchange. Only occur on young stems. exchange. growth rings - bud scale scars from the last terminal bud bud; they denote flushes of growth (usually per year). Can be used to age stems because usually 1 set of growth rings is produced per year on temperate trees in the Temperate Climatic Zone. temperate Page 12 Stem Anatomy: Dicots and Gymnosperms Dicots Primary Growth Vascular bundles are arranged as a ring between the cortex and pith. The pith and cortex are usually comprised of parenchyma cells. Inside each vascular bundle, the phloem is orientated towards the outside and xylem towards the inside of the stem. The outer surface is covered by the epidermis. Secondary Growth Remnants of the pith occur in the center, surrounded by rings of xylem (one ring for every year), then the cambium. The phloem is ridged (dilated). Rays transverse the xylem and extend into the phloem (where they dilate). The outer surface is covered by the periderm or bark, which occurs as irregular layers. Page 13 Stem Anatomy: Monocots Stem Primary Growth The vascular bundles are The randomly scattered in the ground tissue (usually comprised of parenchyma cells). Each vascular bundle is surrounded by a bundle sheath and contains xylem orientated towards the inside and phloem towards the outside of the stem. The outer layer is epidermis. outer Page 13 Root Anatomy Root Primary Growth Root anatomy is virtually the same for monocots, dicots and gymnosperms. The Root dicots and vascular tissue occurs in the center, which is surrounded by two rings of cells, vascular rings the pericycle and endodermis, then the cortex and epidermis. The cell walls of pericycle the endodermis that are perpendicular to the root surface (i.e. the radial and anticlinal walls) are sealed by a suberized band called the Casparian strip. Root anticlinal walls) suberized band Casparian Root hairs are extensions of the epidermal cells. hairs Secondary Growth Similar to stem secondary growth. Woody root has remnants of xylem instead of lem pith pith Page 14 Leaf Morphology: Simple Leaf Leaf tip - the terminal point of the leaf the blade or lamina - the flattened, the green, expanded portion of a leaf. green, margin - edge of a leaf. midrib - the most prominent central vein in the a leaf. leaf. lateral veins - secondary veins in a leaf. petiole - the leaf stalk (connects blade to the stem). stem). stipules - leaf-like appendages (at the base like of petiole of some leaves). Page 14 Leaf Morphology: Compound Leaf Leaf leaflet - secondary leaf of a secondary compound leaf. compound rachis - an extension of the petiole an bearing leaflets. bearing petiolule - the leaflet stalk. petiole - the leaf stalk. stipules - leaf-like appendages (at like the base of the petiole of some the the leaves). leaves). Page 14 Leaf Morphology: Leaf Arrangement Leaf alternate - one leaf attached per node, one usually staggered (spiral) along stem. opposite - two leaves (a pair) attached two per node, usually opposite each other. other. whorled - three or more leaves attached three per node, usually equally spaced per node, around the node. around Page 15 Plant Morphology: Leaf Venation pinnate feather-like, net venation with lateral veins extending from a central midrib (dicots - ex. elm, oak) palmate finger-like, net venation with several major veins diverging from the union of the petiole and the leaf blade (dicots - ex. maple) parallel principal veins parallel to the axis of the leaf (monocots - ex. grasses). Page 15 Plant Morphology: Leaves simple Leaf consists of one blade pinnately compound leaflets arising from along both sides of the rachis (ex. rose, pecan). palmately compound leaflets all arising from the same location at the top of the petiole (ex. buckeye, schefflera, poison ivy, bean). Page 16 Plant Anatomy: Angiosperm Leaves Plant Note: Monocots do Note: not have palisade parenchyma parenchyma Page 16 Plant Anatomy: Gymnosperm Leaves Leaves Page 17 Function of Leaf Parts: Stomata Function stoma - an open aperture (the stomatal pore) in the epidermis an stomatal pore) surrounded by 2 guard cells. surrounded by stomata - plural plural Usually more frequent on epidermis of lower leaf surface. Found on some herbaceous stems, fruits and petals. Daily Cycle C-3 and C-4 Plants Plants a) open during day a) b) closed during night CAM Plants CAM a) open during night a) b) closed during day Graphic source: http://www.marietta.edu/~spilatrs/biol103/photolab/physfacs.html Page 17 Function of Leaf Parts: Stomata Function Mechanism of Opening Mechanism a) open when guard cells are turgid (due to water uptake in response to potassium influx) in b) closed when guard cells are flaccid (due to water loss b) in response to potassium efflux) in Page 17 Function of Leaf Parts: Stomata Function Designed for gas exchange Designed a) CO2 in and 02 out for photosynthesis a) b) CO2 out and 02 in for respiration c) H20 out during transpiration Page 17 Function of Leaf Parts: Mesophyl Mesophyl Palisade parenchyma a) Contains 70-80% of the chloroplasts in the leaf. b) Specialized for photosynthesis - because it contains a large number of chloroplasts and it occurs towards the top side of leaf. Spongy parenchyma a) Contains large air spaces b) Specialized for gas exchange - because of the large air space and more stomata occur in the epidermis of lower leaf surface. Page 17 Function of Leaf Parts: Mesophyl Mesophyl Sun Grown Maple Leaf Shade Grown Maple Leaf Sun Grown Leaf Thicker, due to thicker palisade parenchyma layer Smaller size Shade Grown Leaf Thinner, due to thinner palisade parenchyma layer, therefore, higher proportion of spongy mesophyll. Larger size Softer and more pliable Images from http://www.lima.ohio-state.edu/biology/archive/leaves.html Pages 19 & 20 Plant Morphology: Flowers Plant flower - the reproductive organ of higher plants (e.g. angiosperms or flowering plants), which contains at least 1 female reproductive part, the pistil, and/or 1 male reproductive part, the stamen. Flower Types Complete - contains all floral parts, i.e. sepal, petal, stamen and pistil Incomplete - lacks one or more of the floral parts Perfect - contains both pistil and stamen (may or may not have sepal or petal) Imperfect - lacks either pistil or stamen (may or may not have sepal or petal) pistillate (female) - contains only pistil (may or may not have sepal or petal) staminate (male) - contains only stamen (may or may not have sepal or petal) Sterile - both stamen and pistil are absent, or are non-functional Pages 19 & 20 Plant Types Based on Flower Type Present Monoecious both staminate (male) and pistillate (female) flowers occur on the same plant Dioecious staminate (male) and pistillate (female) flowers occur on separate Picture source: www.life.uiuc.edu Pages 19 & 20 Plant Morphology: Fruits Plant fruit - a ripened or matured ovary and its contents plus any accessory tissues. pericarp - the fruit wall, which developed from the ovary wall Composed of 3 layers: 1) exocarp - outer layer of the pericarp 2) mesocarp - middle layer of the pericarp 3) endocarp - inner layer of the pericarp. Pages 19 & 20 Plant Morphology: Seeds Plant seed - a ripened or mature ovule consisting of an embryo seed ripened with associated stored food and covered by a testa. with and testa testa - protective, outer most layer of seeds; commonly testa protective, called seed coat. called Page 21 Photosynthesis Photosynthesis photosynthesis - the process in which carbon dioxide the (CO2) and water (H2O) are used to produce (CO O) carbohydrates and evolve oxygen (O2) in the presence of carbohydrates in light and chlorophyll; the net result is that light energy (radiant energy) is converted into chemical energy in the form of fixed carbon compounds (carbohydrates). form chloroplast - the green plastid in which photosynthesis the occurs. Page 21 Chloroplast Components Chloroplast chlorophyll - the green plant pigment in chloroplasts that absorbs the light needed for photosynthesis. thylakoids - flattened, sack-like membranes inside a chloroplast; contain the chlorophyll. granum (pl.grana) - stack of thylakoids. stroma lamellae (pl. stroma lamella) – tubular membrane that connects grana in the chloroplast. stroma - the fluid matrix of the chloroplast. Page 21 Two Reactions in Photosynthesis Two Light Reaction - the reaction that uses the water the and light energy and evolves oxygen. It is also called and light the Hill Reaction. the 6 H20 12 H + 3 O2 12 Dark Reaction - the reaction that uses the carbon the dioxide and produces the carbohydrate. It is also called the Calvin-Benson Cycle or Photosynthetic called Photosynthetic Carbon Reduction (PCR) Cycle. Carbon 6 CO2 + 6 H C6H12O6 Page 22 Biochemical Reactions of Photosynthesis Biochemical C-3 Pathway Page 23 Photosynthetic Pathways Photosynthetic C3 Day C4 CAM stomata close (to conserve water during hot dry day.) dry 4-carbon acid breaks carbon down to release C02 inside down inside the leaf for dark reaction. the stomata open. stomata C02 fixed into 4-carbon C0 carbon acids (malate) and stored acids and in the vacuole of mesophyll cells until the mesophyll cells next day. next many desert plants succulents, cacti. stomata open stomata open. stomata stomata CO2 fixed into 4-carbon carbon fix CO2 by dark fix by acid in mesophyll cells. mesophyll reaction into 3reaction carbon sugar acids. 4-carbon acid travels to carbon bundle sheath cells and releases C02 for the dark releases for reaction. reaction. stomata close. stomata stomata close. stomata Night Examples most plants bean, apple, bean, tomato. tomato. some grasses corn, sorghum. Page 23 C4 Pathway C4 Note: All photosynthetic pathways have Note: the same light reaction the Pages 24 & 26 Factor Affecting Photosynthesis Photosynthesis 1) Light (Radiant Energy) a) Quality – Wavelength or Quality Wavelength color of light color 1) 2) 3) 4) Colored coverings Tungsten or incandescent Tungsten lights lights Fluorescent lights High intensity Discharge High (HID) lights (HID) b) Quantity – Intensity of Quantity Intensity amount of light amount a) b) c) Supplemental lighting Row orientation Orientation of plants Orientation around buildings/structures around Pages 24 & 26 Factor Affecting Photosynthesis 2 Factor 1) Carbon dioxide a) b) c) Greenhouse depletion Greenhouse during day and ventilation during Carbon dioxide Carbon enrichment enrichment CAM plants 2) 3) 4) 4) 5) 6) Temperature Leaf Age Leaf Water Stress Nutrition Leaf damage and Leaf stomatal closing stomatal Page 25 Effect of Light Quality on Photosynthesis Effect Light Quality Under a Plant Canopy in the Shade Sunlight has all colors of visible light in similar proportions. When When light passes through a leaf, more blue, orange and red wavelengths light hs are removed by chlorophyll and carotenoids and more green-yellow carotenoids yellow and far red wavelengths are transmitted. Therefore, the shade of a and Therefore, tree is richer in green-yellow and far red wavelengths. Plants are tree Plants partially "color blind" to the light in the shade. partially Page 25 Effect of Light Quality on Photosynthesis 2 Effect Light Quality from Artificial Light Sources Artificial lights emit different wavelengths (colors) of visible light. Fluorescent light are highest in the blue and yellow-orange region of the spectrum. Incandescent (tungsten) lights are poor in the blue region, moderate in the green region, high in the red and far red region of the spectrum, with up to 50% of their output in the infra red region (that's why they're hot). Red light triggers flower formation Blue light triggers leaf formation Page 26 Effect of Light Quantity Effect Relationship between Light Intensity and Rose Yield (From: K. Post and J.E. Howland. Proc. Amer. Soc. for Hort. Sci. 47:446-450, 1946) Page 27 Respiration Respiration Breaks down glucose and releases energy Breaks C6H12O6 + 6 O2 => 6 CO2 + 6 H2O + 38 ATP => Respiration using oxygen releases the most energy However the theoretical release of 38 ATP is never attained because the process itself uses energy. Net gain has been estimated at 28 to 30 ATP gain Some energy can be obtained without oxygen, but resulting compounds may be toxic resulting Plants growing in low oxygen environments (wetlands plants) have adapted and use different respiration pathways Page 27 Respiration: Glycolysis Glycolysis 1st Respiration Respiration Reaction Reaction Does not require oxygen for reaction reaction Occurs in cytosol cytosol Glucose (6C) broken into 2 pyruvic acid (3C) pyruvic acid molecules molecules Energy (2 ATP) produced only in the presence of oxygen oxygen Glucose + 2 NAD+ + 2 Pi + 2 ADP → Glucose NAD 2 Pyruvate + 2 NADH + 2 ATP + 2 H2O Pyruvate NADH Page 27 Respiration: Anaerobic Fermentation Respiration: 2nd Respiration Respiration Reaction in absence of oxygen absence Occurs in cytosol cytosol Pyruvic acid (3C) Pyruvic acid broken into 1 CO2 broken and 1 ethanol and (2C) molecule (2C) Produces very limited energy limited glucose → 2 ethanol + 2 CO2 + 2 ATP glucose ATP Page 27 Respiration: Krebbs Cycle Krebbs 2nd Respiration Reaction in Respiration presence of oxygen Occurs in mitochondrion matrix matrix Pyruvic acid (3C) broken Pyruvic acid into 3 CO2 into Recycles 4C acid Recycles Occurs in concert with the cytochrome system to cytochrome system release energy release Page 27 Respiration: Cytochrome System Cytochrome Respiration Reaction Concurrent with the Krebs Cycle the Occurs in inner membrane of mitochondrion mitochondrion Hydrogen remaining from glucose molecule is bound with oxygen and this releases energy releases Page 28 Factors Affecting Respiration Factors Important for storage and transport. Plant cells continue Important to respire after harvest depleting carbohydrates to 1. 2. 3. 4. 5. 5. 1. 2. 3. 4. Temperature Oxygen Carbon dioxide Humidity : High humidity => Low Respiration Humidity Ethylene Production Damaged Tissue > Healthy Tissue Old Tissues > Young Tissues Fruit Ripening Water Content: Dry tissue => No Cytosol => No respiration. Water Cytosol => Example: dry seeds Example: Page 28 Factors Affecting Respiration: Fruit Ripening Factors Page 28 Factors Affecting Respiration: Temperature Factors Respiration Respiration Tissue Tissue death death 32°F 32 Tissue Tissue death death Temperature Page 28 Factors Affecting Respiration: Oxygen Factors Page 28 Factors Affecting Respiration: Carbon Dioxide Carbon Respiration Respiration 2-5% Carbon dioxide Page 28 Optimal Storage Optimal Controlled Atmospheric Storage Controlled High CO2: 2-5% High Low O2 : ~3% Low Low Temperature: ~ 32°F Low High Humidity: ~ 90% High Ethylene removed Ethylene Hypobaric Storage Hypobaric Uses low pressure to reduce O2 and remove ethylene from the air and plant tissue. Otherwise same as above. the Page 29 Overall Chemical Reactions of Photosynthesis and Respiration of Page 29 Review Photosynthesis Review Reactions Light Reaction Light (Hill Reaction) (Hill Dark Reaction Dark (Calvin-Benson (Calvin Benson Cycle, PCR) Cycle, When When Occurs Occurs only in only light light only when only light reaction occurs occurs Where Where Occurs Occurs grana of of chloroplast chloroplast stroma of of chloroplast chloroplast Inputs H20, 0, light energy light CO2 Outputs O2 carbohydrate Page 29 Review Respiration Review Reactions Glycolysis Anaerobic Anaerobic Fermentation Fermentation When When Occurs Occurs all the time all (O2 present) (O only when only O2 absent Where Where Occurs Occurs cytosol of cytoplasm cytosol of of cytoplasm cytoplasm Inputs Glucose - Outputs metabolic energy CO2, ethanol, ethanol, some metabolic metabolic energy CO2, metabolic metabolic energy H2O, O, metabolic metabolic energy (ATP) Krebs Cycle Krebs (TCA Cycle) (TCA Cytochrome System all the time all (O2 present) (O all the time all (O2 present) (O matrix of matrix mitochondria mitochondria inner inner membranes of mitochondria of - O2 ...
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