botany exam 3

briggs experiment

split stem tip with glass to show how auxin moves across stem tip and away from light

blue light

phototropism responds, stomatal openings respond, green light switches response off

gravitropism

inhibitor in root cap, negative in shoots, positive in roots, statoliths, starch sheath cells, cytokinin in root cap

statoliths

gravity sensors

starch sheath cells

surrounds vascular tissues, continues in roots with endodermis

thigmotropism

differentiate growth on inside and outside of tendril, nyctinastic movements, thigmonastic movements, thigmomorphogenesis

nyctinastic movements

up and down movements in response to daily rhythms

thigmonastic movements

leaves open and close, ion fluxes at action potentials, mimosa plant

thigmomorphogenesis

gene expression induced by touch, suggests role for calcium in growth response

heliotropism

base of inflorescence has ion influxes that change direction towards sun, sunflowers

photoperiodism

response to duration of timing of day and night, day neutral means no critical value, run by phytochrome photoreceptor, dormancy

phytochrome photoreceptor

red and far red photoreceptors, light absorbing chromophore, flowering regulation

flowering regulation

photoperiod, gibberellins, hypothetical florigen, genetic control, FLC

hypothetical florigen

found mRNA FT and FT protein

FLC

flowering locus control, inhibits flowering, switched off after vernalization

auxins

Discovered by Went in 1926, produced from tip to base, causes phototropism, has polar transport, basipetal transport, causes fruit development, regenerates xylem, supresses growth, delays abscission

basipetal transport

when hormones go from tip to base of plant

cytokinins

Found primarily in root tips, transported via xylem from roots to shoots, promotes cell division

ethylene

synthesized from methionine, is a response to stress, moved by diffusion from site of synthesis, causes fruit ripening and senescence and abscission

ABA

abscisic acid misnomer, prevents premature seed germination, roots respond to water stress by increasing production, causes stomata to close, viviparous mutants cant make ABA or reduced sensitivity, K+, Cl-, malate flow in and out

gibberellins

GA, in young tissues of shoot and developing seeds, transported in xylem and phloem, hyperelongation by stimulating both cell division and elongation

primary metabolites

molecules found in all plant cells necessary for life

secondary metabolites

stored in vacuoles, healing, insecticides, allelopathic, important for survival and propagation, and have phytoalexins

alkaloids

secondary metabolites that include morphine, cocaine, caffeine, nicotine, theobromine, theophylline, atropine, quinine, vinblastine, and reserpine

terpenoids

largest class of primary and secondary metabolites that include lemonine, menthol, taxol, cardiac glycosides, carotenoids, and plastoquinones. composed of isoprene units

phenolics

secondary metabolites that include flavenoids, anthocyanins, flavenols, salicylic acid, aloin, and chysophanic acid

plastids

secondary metabolites that include chromoplasts, amyloplasts, and eitoplasts

morphine

an alkaloid found in the afgan poppy plant and fruit, is a psychoactive drug

cocaine

alkaloid found in cocoa plant in andes mountains, can be insecticide and numbing for rhinoplasty

caffeine

alkaloid found in fruits of Coffee arabica, Teobroma cacao, and Camellia sinensis, is an allelopathic stimulant , from ethiopia, produced mainly in brazil, vietnam, and columbia

allelopathy

when a compound is leeched into the soil to reduce competition from other plants

nicotine

alkaloid found in tobacco Nicotiana tabacum, stimulant phytoalexin

theobromine

alkaloid found in cacao, insecticide, used for vascular disorders, named after Theobroma

theophylline

alkaloid found in Camellia seniensis, insecticide, helps respiratory diseases

atropine

alkaloid found in deadly nightshade Atropa belladonna, Hyoscymus muticus, and Egyptian henbane, named after atropa, stimulant that dilates pupils

quinine

alkaloid found in fever bark tree, rubiceae family, treats malaria

vinblastine

alkaloid found in periwinkle Vinca rosea, helps fight leukemia

reserpine

alkaloid found in Rauvolfia serpentina in india, treats hypertension, ancient medicinal plant

lemonine

secondary metabolite terpenoid found in lemons

menthol

secondary metabolite terpenoid found in mint

taxol

secondary metabolite terpenoid found in yew trees, found in the bark, used for pest resistance and is anti-cancerous

cardiac glycosides

secondary metabolite terpenoid found in milkweed and foxgloves, sugar unit attached, treats heart faliure, digitoxin

rubber

secondary metabolite, largest terpenoid compound, pest resistance from bark of tree, latex, found in Hevea brasiliensis, has up to 100,000 isoprene unites

terpens use

made of isoprene gas units, emitted in light, cools plants down, smoke of smoky mountains

flavenoids

phenolic pigments for flower color

flavenols

sunscreen for plant

sylacilic acid

phenolic produced when plant gets pathogenic attack, found in willow bark and is airborne for other plants, used for asprin

aloin

phenolic laxative found in aloe and used for insecticides

chysophanic acid

phenolic found in aloe and used for skin healing and insecticides

chromoplasts

plastid with oil bodies

amyloplast

plastid that stores starch

eitoplast

plastid that contains prolamellar bodies, chloroplasts move to walls parallel to leaf when in dim light, move to walls perpendicular when in bright light

etiolation

eitoplast beocomes chloroplast when placed in light

phytoalexins

antimicrobial compounds found in secondary metabolites responsible for healing and warding off infection

carotenoids

primary metabolite terpenoid that produces yellow, orange, and red pigments

plastoquinones

PQs or QAQBs, primary metabolite terpenoid responsible for cell transfer during photosynthesis

lignin

Secondary metabolite that is a phenolic structural supporter

tannins

Secondary metabolite that matures fruits, is a pest repellent, found in central vacule, and blocks formation of endothelin

endothelin

peptide that raises blood pressure and causes heart disease

calvin cycle

18 atp and 12 g3p, fixation, reduction, regeneration

salvage PGA

calvin cycle in chloroplast, oxidation in peroxisome, mitochondrion reduces into glycerate

FT

flowering time promotes flowering