Exam 2 Notes Review Flashcards
(148 cards)
1
Q
Autotrophic
A
plants that make all organic materials from inorganic materials in the soil
2
Q
What is the relationship between pH and ion absorption?
A
-plants can displace ions in the soil to make it more acidic/alkaline
-different ions are available for absorption at different pH levels
3
Q
What is the relationship between mineral/silicate phases and ion absorption?
A
silicon phases hold minerals tighter than mineral phases
4
Q
Mineral
A
inorganic element
5
Q
Essential nutrient
A
a substance needed to survive and complete the lifecycle that is necessary for the synthesis of organic compounds
6
Q
Beneficial nutrient
A
has value to the lifecycle but isn’t required
7
Q
Deficiency zone
A
not enough nutrient available
8
Q
Critical concentration
A
able to reach 90-95% of max growth
9
Q
Adequate zone
A
the plateau at which more nutrient does not provide an advantage
10
Q
Luxury zone
A
the 2nd half of the adequate zone where the soil can lose 1/2 its mineral concentration and still be at critical concentration
11
Q
Toxic zone
A
abundant nutrient content becomes harmful
12
Q
Micronutrients
A
chlorine, iron, manganese, sodium, zinc, copper, nickel, molybdenum
13
Q
Hoagland nutrient solution
A
solution of minerals and nutrients for plant growth
14
Q
Macronutrients
A
nitrogen, potassium, calcium, magnesium, phosphorus, sulfur, silicon
15
Q
What are the 3 ways minerals are classified and sorted?
A
-amount required
-biochemical function
-mobile vs immobile
16
Q
What are the group 1 nutrients and how are they classified?
A
-nitrogen and sulfur
-elements that form bonds with carbon
17
Q
What are the group 2 nutrients and how are they classified?
A
-phosphorus, silicon, boron
-energy storage/structural integrity
18
Q
What are the group 3 nutrients and how are they classified?
A
-potassium, calcium, manganese, chlorine, magnesium, sodium
-remain as dissolved ions
19
Q
What are the group 4 nutrients and how are they classified?
A
-iron, zinc, copper, nickel, molybdenum
20
Q
Which elements are mobile?
A
nitrogen, potassium, magnesium, phosphorus, chlorine, sodium, zinc, molybdenum
21
Q
Which elements are immobile?
A
calcium, sulfur, iron, boron, copper
22
Q
What does it mean when a nutrient is mobile/immobile?
A
mobility is the ability of a nutrient to move within the phloem once settled inside the plant
23
Q
What are 3 ways plants can acquire nutrients?
A
-root uptake
-leaf uptake
-mycorrhizal fungi
24
Q
When is leaf uptake effective?
A
-leaf uptake is only effective for phloem-mobile nutrients
-may be more effective than root transport for copper, iron, and manganese
25
Foliar application
a spray application of nutrients through the leaves
26
Describe the relationship between fungi and nutrient uptake in plants
The fungi sends its mycorrhiza into the plant cortex by breaking down portions of the cell wall (the plant helps with this). The fungi can sense nutrient availability across long distances and move it towards the host plant. In return, the plant provides sugars from photosynthesis to the fungi.
27
What benefits can be gained from manipulation of mineral transport in plants (GMO)?
-increase growth and yield
-increase plant nutritional quality and density
-increase removal of soil contaminants (phytoremediation)
28
What is the structure of roots grown in dry vs wet soils?
-wet growth roots tends to be more spread out and long
-dry growth roots tend to be more compact and short
29
What does mucigel do?
it is secreted by the roots and carries signals into the soil
30
Why are root tips so important in nutrient uptake?
-primary site of uptake
-active site of growth
-nutrients carried via bulk flow into the soft/undeveloped cell walls
-maintains a concentration gradient
31
Integral proteins
pass completely through the membrane and serve as a conduit for transport through the membrane
32
Peripheral proteins
associated with one face of the membrane and may serve as receptor or communication proteins
33
gradient of chemical potential (μ)
the concentration gradient for uncharged solutes
34
electrogenic pumps
-drive protons across the membrane to create a proton motive force
-typically ATPases
35
ATPases
enzymes that split ATP to provide the energy to pump their target solute
36
electrochemical potential (μj)
has two parts, the concentration and the charge
37
The Nernst equation
the equation that predicts the Nernst potential (Ec), which assumes the active/passive transport of an ion across a membrane
38
Passive transport
movement down the electrochemical gradient from a more positive μj to a more negative μj
39
Active transport
movement against the electrochemical gradient from a more negative μj to a more positive μj
40
Simple diffusion
-passive
-bi-directional
-slow
-particles can move directly though the membrane and are usually smaller and both slightly hydrophobic and hydrophilic
41
Channel diffusion
-passive
-simple diffusion
-unidirectional
-fast
-no solute interaction
-through a protein channel, usually moves charged ions
42
Carrier protein diffusion
-passive
-NOT simple diffusion
-up or down the concentration gradient
-moderate speed
-interacts with solutes
-protein moves molecule through a protein channel
43
Active diffusion
-uses energy
-against the concentration gradient
-pump
44
Name the types of diffusion based on speed
pumps->simple->carrier protein->channel
45
Symport
-active transport
-if the hydrogen and substrate are moving in the same direction
46
Antiport
-active transport
-if the hydrogen and the substrate are moving in opposite directions
47
Pumps
-movement against the gradient
-unidirectional
-very slow
-interaction with solute
-direct energy usage
48
What are membrane transporters specialized in?
-location
-structure
-solute they transfer
-function
49
Anion channels
maintain charge between cytoplasm and vacuole
50
Tonoplast transporters
move sugars, pigments, and contaminants to the vacuole
51
Plant cells segregate ions based on ____ and ____.
-function
-toxicity
52
What is the formula for nitrogen assimilation?
NO3 -> NO2 -> NH4+ -> amino acids
53
What is the formula for nitrate reduction? Where does it take place?
NO3- + NAD(P)H + H+ 2e- ->NO2- + NAD(P)+ + H2O
cytoplasm
54
What is nitrate reduction mediated by?
nitrate reductase
55
What does nitrate reduction form?
nitrate, which is highly toxic
56
Nitrate reductase is a homodimer that contains both a ____ and a _____.
-Heme group
-FAD group
57
What is nitrate reductase activated by?
light, carbohydrates, environmental factors
58
What is the formula for nitrite reduction? Where does it take place?
NO2- +6FDred + 8H+ +6e- ->NH4+ +6FDox + 2H2O
chloroplast
59
What does nitrite reduction form?
ammonium, which is highly toxic
60
What is nitrite reduction mediated by?
nitrite reductase
61
Glutamine
It is synthesized from glutamate and ammonium by the enzyme glutamine synthetase. Glutamine can serve as a primary carrier of ammonium in many metabolic pathways. It can transport ammonium to various cellular locations for further processing and assimilation.
62
Glutamate
In the process of ammonium assimilation, ammonium ions are incorporated into organic compounds. Glutamate is often a central molecule in this process. Ammonium ions can be directly incorporated into glutamate through the action of the enzyme glutamine synthetase, forming glutamine.
63
What does ammonia assimilation do?
metabolizes the toxic ammonia produced by nitrogen assimilation and photorespiration
64
Why are carbon metabolism and nitrogen fixation coupled?
carbon skeletons are needed to synthesize amino acids
65
Almost every single plant is a ____ host, but not every plant is a host for ____.
-mycorrhizal
-n-fixing bacteria
66
When did the nitrogen fixing relationship between plant and bacteria show up on the evolutionary timescale?
this is a more recent development and is found primarily in angiosperms
67
What is the composition of eukaryote DNA?
half archaea, half bacteria
68
Why are non-photosynthetic chloroplast kept by plants?
they participate in nitrogen fixation
69
What are NOD factors?
Nodulation factors are a unique chemical password used to communicate between bacteria and plants involved in n-fixation
70
Describe the process of nodulation
A plant root hair grows out towards a bacterial grouping and circles around it. Then, the plant breaks down its own cell wall, leaving only the cell membrane to let the bacteria inside. The bacteria move through the hair until they are transported in golgi vesicles and are fused with the cell membrane. From here they can continue through the cell layers.
71
What does the plant provide to the bacteria?
-safety in nodules
-sugars
-microclimate
-controlled O2 levels via leghemoglobin
72
What enzyme mediates nitrogen fixation? What is this enzyme sensitive to?
-nitrogenase
-O2
73
Does nitrogen fixation require energy?
Yes, a significant amount in the form of ATP
74
What is the formula for nitrogen fixation?
N2 + 8e- +16 ATP ->2NH3 + H2 + 16 ADP +16 Pi
75
What does the bacteria provide to the plant?
ammonium, which is converted to either amino acids or ureides for transport to leaves
76
Name some functions of the cell wall
-compression
-fusion to adjacent cells
-physical barrier
-cell shape (morphogenesis)
-water retention and turgor pressure
-xylem transport and negative pressure
-diffusive barrier
77
Primary cell wall
the initial cell wall around all plant cells
78
Secondary cell wall
a secondary layer of the cell wall deposited around may cells once they have reached their final size
79
Lignified cell wall
a reinforced secondary or tertiary cell wall fortified with lignin, often in woody tissues
80
What are cellulose microfibrils held together by?
hydrogen bonds
81
What properties does the hydrogen bonds in cellulose create?
-flexibility
-practically indestructible (except by some bacteria that create expensive enzymes)
82
What is a rosette make of?
6 cellulose synthase A make a rosette subunit. 6 rosette subunits make a rosette.
83
What do rosettes do?
they sit on the membrane surface and thread microtubules through the cell
84
What transfers materials across the microtubules?
kinesins
85
Describe cellulose microfibril structure (interior, exterior, & overall)
-highly structured interior
-loose exterior
-linkage of sugar creates crystalline structure for the microfibril that may trap other components inside
86
Hemicellulose
binds to cellulose to stabilize its structure
87
Pectin
forms a gell-like matrix that surrounds the celluolse-hemicellulose complex
88
Explain the function of RIC 4 and ROP2/4 in cell growth
RIC 4 shows up at particular spots in the cell near the wall, ROP 2 or ROP 4 is then signaled by RIC 4 to bring vesicles to the plasma membrane, where they (and their contents) are absorbed into the membrane, creating a lobe and expanding the cell
89
Explain what direction microfibrils move away from each other during expansion
Can be moved away from each other vertically, but not slid horizontally. They sit on top of one another and are bonded together using hydrogen bonds. Trying to slide them apart horizontally creates a series of bonds breaking and reforming, whereas separating them vertically (pulling the top one off of the bottom) only has to break the bonds once.
90
If ψp is ____ Y there’s no cellular expansion.
below
91
Explain the acid growth hypothesis
proton sectitions and expansin protein "loosen" connections between wall pectins and polysaccharides
92
What is wall creep?
turgor pressure causes minute cell expansion
93
How do you stop cell expansion?
-remove types of glucan bonds by esterizing them
-increase pectin rigidity
-alter matrix polysaccharide concentration
-cross-link wall phenolics to increase rigidity (linification)
94
Which method of stopping cell wall expansion creates wood and makes the cell shape permanent?
cross-link wall phenolics to increase rigidity (linification)
95
What is a feed forward loop? Why is it used?
A -> B -> C, but A also regulates C.
-Allows for a more pronounced response
-Causes a signal delay, which can filter out short signal fluctuations and makes sure the stimuli persists
96
Signal input module
allows for hierarchical control over a large number of genes
97
MAP kinase network
-multiple input signals
-thick decision layer
-can have multiple output signals
-The plant takes inventory of the situation through signals, runs them through a series of pathways and formulates a response based on that information
98
Photomorphogenesis
a light triggered developmental response
99
What is the range for blue light reactions?
400-500 nm
100
What is the range for phytochrome-mediated reactions?
630-820 nm
101
What is an apical hook and why do plants grow them?
A type of lanky, vertical growth seen when seeds are grown in the dark. They do this because the seed believes it’s underground. The hydrocution (stem) thickens and curves over at the top to ‘push through the soil’ and minimize damage to the leaves.
102
What type of light triggers germination?
red light
103
What type of light stops germination?
far-red light (the light still thinks it's underground)
104
What type of light goes deepest into the soil?
far-red light
105
Phytoreversibility
there are two forms of phytochrome that switch back and forth depending on the presence of red/far-red light
106
Pr
a form of phytochrome that absorbs red light (inactive)
107
Pfr
a form of phytochrome that absorbs far-red light (active)
108
Fluence
a type of measurement that records number of photons that a plant receives of photosynthetically active radiations
109
What happens when different plants receive signals from phytochrome?
All plants receive the same signals from phytochrome. However, different plants change what they do with and how they react to that information.
110
What is the structure of Chromophore: phytochromobilin in Pr vs Pfr?
Red light converts cis to trans conformation
111
What forms during morphogenesis?
basal plant body
112
What forms during organogenesis?
organized structures
113
What forms during differentiation?
specialized cell types
114
What are the 3 steps of embryogenesis?
morphogenesis, organogenesis, differentiation
115
Quiescent center cell
the direction which neighbor cells divide in relation to the quiescent center cell changes the type of cell they become
116
Where are the stem cells in the growing root and what do they do?
they surround the quiescent center cell and differentiate into their appropriate cells
117
What kind of signals does the quiescent center send out?
auxin and cytokinin
118
What is the relationship between auxin and cytokinin?
they have an antagonistic relationship and don't like to be sent to the same cells
119
What does L1 produce?
epidermal tissues
120
What do L2 and L3 produce?
internal tissues
121
The arrangement of leaves on a stem is dependant on ____.
auxin
122
Why do mature leaf epidermal cells have wavy margins?
helps resist tearing apart under environmental stress
123
Stomata are found where?
Almost all above-ground epidermis tissues
124
What was the original purpose of the stomata?
support desiccation of structures holding pollen/spores
125
What kind of spacing pattern do stomata have?
1-cell
126
Meristemoids are always ____ to the stomata.
Non-adjacent
127
Meristemoids
small, specialized cells that are capable of giving rise to other types of plant cells.
128
What happens when two meristemoids that are next to each other ?
-oriented division (one goes through another round to division to move farther away)
-lateral inhibition (one gives up on being a meristemoid and becomes a pigment cell)
-double-stomata (both become stomatas anyway, doesn't happen very often)
129
What does the four-lips mutant phenotype do?
controls the guard mother cell division (stops division once a certain size is reached)
130
What is the quick way to produce auxin?
break down tryptophans
131
How does a plant store auxin?
by creating a pool of methylated auxin in the cytoplasm
132
How is auxin transferred through the cell so it doesn't react along the way?
auxin is bundled with another compound and sent through the phloem where a hydrolase breaks it into a useable form at the end point
133
What do the PIN genes do?
they transport auxin in different directions
134
How does auxin extend the cell wall?
activating H+-ATPase
135
Obligate regulation
have a fixed requirement for certain environmental factors to induce flowering
136
Facultative regulation
can adjust their flowering time in response to environmental cues, but they are not strictly bound by these cues
137
meristem identity
positive regulation of floral identity genes
138
floral organ identity
direct control of floral identity genes
139
What are the two categories of gene regulate flowering?
meristem identity & floral organ identity
140
What does VERN 1 do?
activates flowering
141
What does VERN 2 do?
inhibits VERN 1
142
What happens when light interrupts a long day plant dark period?
the plant will still flower as long as long days are still present
143
What happens when light interrupts a short day (long night) plant dark period?
the plant will not flower even with a standard short day
144
What is jasmonate signaling in response to?
response to fungal or animal pathogen wounding the plant
145
What is ethylene signaling in response to?
response to non-specific wounding
146
What is salicylic acid signaling in response to?
response to bacterial pathogens
147
Which two signals are volatile? Which is non-volatile?
volatile: jasmonate & ethylene
non-volatile: salicylic acid
148
What is the interaction between signaling pathways?
Multiple can be activated at the same time and work simultaneously. However, they can also inhibit each other, with the strongest signal receiving the most energy from the plant.
