Exam 2 Flashcards
dodder
-parasitic plant with pale stems and piglike haustoria
mutualism
both species benefit
commensalism
1 benefits, other is unharmed
parasitism
-1 is benefited, other is harmed
mycorrhizae
-fungi that is grown in association to roots
-fungus gets sugars from host and plant gets additional water and nutrients
-85-90% of plants have this association
ectomycorrhizae
remain outside of plant cells
endomycorrhizae
-more common
-grow inside plant cells
rhizobium
-bacteria that grow in association with roots of pea plants
-help with nitrogen fixation
human relevance of roots
spices, dyes, insecticides, drugs
cuticle
-made of cutin
-in upper epidermis of leaf
-prevents water loss and bacterial infection
palisade mesophyll
-site of photosynthesis
-tall columnar cells
spongy mesophyll
-photosynthesis, air spaces between cells
lower epidermis
-guard cells that form stomates
-allows diffusion of co2 into leaf and o2 out of leaf
bulliform cells
-in grasses, influence leaf expansion
sun leaves
-multiple palisade cell levels
-thicker leaf
-more photosynthetic material
shade leaves
-thinner
-fewer palisade cells and spongy mesophyll
compass plant
-leaves are oriented to east and west and are perpendicular to ground (not directly hit by sunlight)
barberry spines
modified leaves
flower pot leaf
opened up and has roots inside
floral leaves
-brachts
-colorful to attract pollinators to non-ornamental flowers
carnivorous plants
-most environments with acidic ph soil with low nutrient content
types of pigments
-carotenoids: yellow
-anthocyanin: red
-chlorophyll: green
carotenoids
carotene and xanthophyll
what happens during fall to chlorophyll
chlorophyll breaks down and plant stores mg from it
-this exposes carotenoids
abscission
process by which leaves are shed in fall by deciduous trees
human use of leaves
-mint, shade, food, dyes, fibers, medicine, tea
why do plants need water
-young cells can be 90% water
-enzymatic processes and other chemical reactions
-photosynthesis
-mesophyll cell surfaces must be moist for co2 to diffuse into cell
-cell turgor
osmotic potential of a solution
-a measure of the potential of water to move from one cell to another as influenced by solute concentration
-turgor pressure (pressure potential): pressure of cell contents against cell wall as a result of water entering vacuole
water potential
=osmotic potential + pressure potential
transpiration
-water enters air by way of leaf by transportation
-90% of water entering plant passes through and evaporates
-only 5% is lost through cuticle
pathway of water through plant
soil
root
xylem in root
xylem in stem
leaf (water used in mesophyll for photo.)
cohesion
-water flows from less negative to more negative potentials
-or from higher water potential to lower water potential
guard cells and stomate in transpiration
-change in turgor pressure when exposed to changes in light, co2, and water conc.
active transport of k+
-k+ pumped into vacuole while guard cells photosynthesize
-atp produced via respiration of sugars
-k+ leaves cell when guard cells stop photosynthesizing
stomate response to water stress
-close when water stress occurs
-abscisic acid is produced in leaves subject to water stress causing membrane leakages from cells
-k+ ions leave guard cells, water follows and cells deflate
cactus
-store co2 in organic acids
-co2 enters stomates at night
-co2 is released in cells to allow photosynthesis during day
guttation
-loss of water in liquid form from within plant through hydathodes at tips of veins in some herbaceous plants
-minerals cause water to flow into xylem
pressure flow hypothesis
-explanation for how dissolved sugars move between locations in plants
-aphids used to study translocation of food substances in solution by phloem
-source: leaf
destination of sugars (sink)
-photosynthesis in leaf (pumped by active transport into sieve tube members by osmosis)
-h2o from xylem passes into sieve tubes, creates turgor pressure
-sugars removed at sink by active transport
-h2o flows from sieve tubes back to xylem
macronutrients
CHNOPS
micronutrients
Zn
B
Mn
Cu
metabolism
all chemical reactions that take place in organism and support life
anabolism
-enzymes help form chemical bonds and build molecules
-building larger molecules
catabolism
-enzymes help break chemical bonds and break down molecules
-breaking larger molecules into smaller ones
-photosynthesis
ROYGBIV
R: longer wavelength, lower energy
V: short wavelength, higher energy
C3
-photosynthetic pathway with higher temps leading to decrease in photosynthesis
C4
photosynthesis more at higher light intensity and increase in temp doesn’t affect photosynthetic rate
-tropical plants
cam
-ex. cactus
when is new chlorophyll produced
-throughout growing season
light dependent reactions
-energy in sunlight is captured and converted to energy of chemical bonds
-produces: atp, nadph, o2
-occurs in thylakoid
light independent reaction
-co2 chemically reduced and carbohydrate is formed
-Calvin cycle
-product: carbohydrate
-occurs in stroma
engelmanns experiment
-algae exposed to light
-bacteria attracted to o2 producing cells
-most effective light present in purple/blue and red/orange
chlorophyll a
-blue-green
-more abundant
chlorophyll b
yellow-green
-transfers energy to chlorophyll a
chemiosmosis
-describes how e- boosted to higher energy levels in ps1 and ps2 lead to production of atp and nadph
Calvin cycle
-enzyme called rubisco (most abundant enzyme on earth)
-occurs in stromas of chloroplasts
g3p
-glyceraldehyde 3 phosphate
-2 makes a glucose
-can be used in many synthesis pathways including:
fatty acid, amino acid, glucose phosphate
cell respiration
-aerobic
-4 phases: glycolysis, prep run, cac, etc
glycolysis
-occurs in cytoplasm
-splitting glucose into 2 3c molecules
-net 2 atp, 2 nadh
preparatory reactions
-occurs in mitochondrial matrix
-2 nadh
citric acid cycle
-occurs in mitochondrial matrix
-2 atp, 6 nadh, 2 fadh2
etc
-occurs in crustal of mito.
-34 atp
fermentaion
-bacteria, fungi, animals
-lactic acid (bacteria and muscles in humans)
-ethyl alcohol (yeast)
primary metabolic pathways
associated with energy
secondary metabolic pathways
-metabolic processes not needed for normal growth and development
-chemicals found in plants that play role in primary pathways
-secondary compounds associated with resistance to herbivores and bacteria
alkaloids
-compounds produced in small quantities but are toxic
-codein, nicotine, quinine (malaria treatment)
phenolics
-lignin (woody plants), salicin (aspirin precursor in willows), thc
terpenoids
-camphor (disinfectants, medicinal oils), menthol, rubber
assimilation
-conversion of sugars to lipids, proteins, or other carbs (sucrose, starch, cellulose)
digestion
-conversion of starch and other insoluble carbs to soluble forms (through hydrolysis)
-ex. endosperm starch grains being digested to provide simple sugars to developing embryo
gravity
-shoots grow up (against gravity), roots grow down
growth
irreversible increase in mass due to division and enlargement of cells
development
-coordination of growth and differentiation of a single cell into multicellular tissues and organs
differentiation
-as cells enlarge, cells develop different forms adapted to specific functions
what can influence development
genes, internal signals, external environmental conditions
nutrients
furnish elements and energy for plant growth and maintenance
vitamins
-play an important role in reactions catalyzed by enzymes
-vitamins are coenzymes or parts of coenzymes
-needed in small quantities (most made by plants)
hormones
organic substances that influence many developmental processes
plant hormones
-act by binding to specific receptor molecules
-once bound, they trigger a series of biochemical reactions (called signal transduction)
main plant hormone types
auxin
gibberellins
ethylene (2 c chain)
cytokinins
abscisic acid
-rest ring compounds
cell signaling
signal to receptor followed by cell response
went’s experiment with coleoptiles
-coleoptile tip onto agar and agar onto decapitated coleoptile
-auxin: influenced bending of coleoptile
-coleoptile: sheath covering shoot tip of embryonic leaves of monocots
auxins
-made in apical meristem (actively growing parts)
-stimulates cell enlargement
-can trigger production of other hormones and influence root initiation and stem growth
-movement is polar (away from source) and requires atp
bioassay of auxin
angle of curvature is measured and compared to curvature caused by known concentration of auxin
indole acetic acid used for…
-rooting of cuttings
-flowering and fruit set
-fruit retention
-weed control
gibberellins can affect…
-flowering
-stem length (not conifers)
-bud and seed dormancy
-movement is not polar and is through xylem and phloem
cytokinins
-stimulate cell division (promotes g2 to mitosis progression with presence of auxin)
-role in enlarging cells, delay of aging in leaves
-synthesized in root tips and germinating seeds
abscisic acid
-growth inhibiting hormone
-synthesized in plastids
-inhibits growth promoting effects of other growth promoting hormones
-once thought to play role in abscission
-prevents germination of seeds in fruit
ethylene
-ripening of fruits can be accelerated
-ethylene production increases if fruits are bruised
-pea seedlings growing in soil produce this if they encounter interference
-promotes abscission of leaves
