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Botany
plants and people, plant development, photosynthesis
222
Biology
Undergraduate 3
11/11/2012

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Cards

Term
How long have homo sapiens been around?
Definition
150,000 years
Term
How long have people been farming?
Definition
10,000 years
Term
How did people get food before farming?
Definition
Hunting and gathering
Term
What evidence do we use to determine when farming began?
Definition
Fossils and coprolites
Term
What are coprolites?
Definition
Fossilized poop
Term
how much of the protein consumed worldwide comes from plants?
Definition
About 70%
Term
What are the two main sources of plant protein intake in humans?
Definition
Legumes (18%)
Cereals (70%)
Term
What countries make up the fertile crescent?
Definition
Syria, Turkey, Iran, Iraq, Israel, and Jordan
Term
Where was barley first domesticated?
Definition
The fertile crescent
Term
Where was wheat first domesticated?
Definition
The fertile crescent
Term
where were peas first domesticated
Definition
The fertile crescent
Term
Where were apples first domesticated
Definition
Asia
Term
Where were soybeans first domesticated
Definition
Asia
Term
Where were citrus fruits first domesticated?
Definition
Asia
Term
Where was coffee first domesticated?
Definition
Africa
Term
where were pinapples first domesticated?
Definition
The new world
Term
Where was cocoa first domesticated
Definition
The new world
Term
Where were apricots first domesticated?
Definition
Asia
Term
Where was diploid cotton first domesticated?
Definition
Africa
Term
Where was triploid cotton first domesticated?
Definition
The new world
Term
Where were bananas first domesticated?
Definition
Asia
Term
Where were most spices and herbs domesticated?
Definition
The old world
Term
Where were grapes first domesticated?
Definition
The fertile crescent
Term
Where was sugarcane first domesticated?
Definition
Asia
Term
What are the 6 plants that provide more than 80% of the calories humans consume?
Definition
Rice
Wheat
Maise
Potatoes
Sweet Potatoes
Manioc
Term
About how many humans are added to the population each day?
Definition
220,000
Term
How can we produce more food to stop world hunger?
Definition
Increase the productivity of the crops we currently have
Term
What is a good way to find new useful plant species?
Definition
Use ethnobotanical information.(study what plants different cultures use)
Term
How many angiosperm species are there?
Definition
300,000
Term
What are to ways to preserve genetic diversity in plants?
Definition
Conserve various ecosystems
Create germplasm banks (Repositories for varieties of plants)
Term
What are two new and important crops?
Definition
Amaranth
Jojoba
Term
During what geological time period did hominids first evolve?
Definition
Quaternary period.
Term
what 4 genera did hominids evolve through between the common ancestor with chimpanzees and humans?
Definition
Ardipithecus
Australopithecus
Paranthropus
Homo
Term
What parts of the world were hot spots for starting agriculture and domestication?
Definition
Mesoamerica, south american highlands, Yellow and Yangtze river basins, eastern U.S., the fertile crescent, and new guinea highlands.
Term
Where does fossil evidence suggest corn developed?
Definition
Tehuacan valley in Mexico.
Term
What kind of evolutionary force drove domestication?
Definition
Artificial selection
Term
Where was taro first domesticated?
Definition
Tropical Asia
Term
What is millet?
Definition
A member of the grass family related to wheat and corn
Term
What part of taro is edible?
Definition
the tubers
Term
What is a tuber?
Definition
An underground stem that is rich in starches
Term
Where were yams first domesticated?
Definition
Africa
Term
What plant can be used to synthesize contraceptives?
Definition
Yams
Term
What is the name of the plant that is the ancestor of modern corn?
Definition
Teosinte
Term
What is the ear of a teosinte plant like?
Definition
Consists of 8 kernels with hard seeds
Term
Where and why is casava important?
Definition
Important in south america because it produces large starchy tubers.
Term
What plant was domesticated in the U.S. and what does it produce?
Definition
Sunflowers. They produces seeds and oil.
Term
What part of the plant is mace produced from?
Definition
The Aril
Term
What part of the plant is used to make pepper?
Definition
The dried fruits
Term
How is nutmeg made?
Definition
They use the ground up seed to make nutmeg
Term
What two spices were domesticated in the new world?
Definition
Vanilla and allspice.
Term
What are the 14 vital crops that are responsible for 80% of calories we consume?
Definition
wheat, rice, maise, potatoes, sweet potatoes, manioc, sugarcane, sugarbeet, beans, soybeans, barley, sorghum, coconut, and bananas.
Term
How was the jojoba found?
Definition
Using ethnobotanical information
Term
What is characteristic of the jojoba and what is this used for?
Definition
Seeds contain 50% wax. This is used to lubricate machines under extreme pressures. It is also used in food additives and cosmetics.
Term
Why is the Amaranth so important?
Definition
The leaves are edible, and the fruit is tasty and high in protein.
Term
Why is the Solanum cheesmaniae a relative of and why is it important?
Definition
Solanum cheesmaniae is a relative of the tomato and it tolerates high salinity so it can be grown in overirrigated land and land near the sea.
Term
What is the rosy periwinkle used for?
Definition
A natural source of drugs that target certain cancers.
Term
What is milkweed used for?
Definition
The trichomes of the seeds are used to make pillows.
Term
where were the first agricultural settlements found? when were they active?
Definition
Found in the east, the fertile crescent, and the new world around the same time 11,500 years ago.
Term
Where does the embryo develop?
Definition
Inside the ovule
Term
what is plant embryogenesis?
Definition
The formation of an embryo from the zygote.
Term
What are the products when the zygote first divides? Comment on the cell sizes.
Definition
A large basal cell and a smaller terminal cell.
Term
what is the two cell proembryo?
Definition
The basal cell + the terminal cell
Term
What does the apical cell give rise to?
Definition
The embryo
Term
What does the basal cell give rise to?
Definition
The suspensor
Term
What does the suspensor do?
Definition
Transports nutrients to the embryo
Term
What does the 6 cell proembryo look like?
Definition
There are 4 elongated suspensor cells and 2 terminal cells
Term
Where does the developing embryo get food?
Definition
From the mother plant and the endosperm
Term
What is the composition of endosperm?
Definition
Starches and oils
Term
What is the embryo proper?
Definition
The embryo proper is the embryo during the globular stage when you can see the different meristems.
Term
Nucellar tissue is another name for...
Definition
Megasporangium
Term
What happens at the torpedo stage?
Definition
The suspensor undergoes programmed cell death and detaches the embryo from the mother plant.
Term
How does the embryo of a monocot differe from eudicots?
Definition
There is no heart stage, instead a notch develops that seperates the cotyledon from the hypocotyl-root axis.
Term
What happens once the embryo is fully developed?
Definition
The funiculus is no longer needed, so it detaches leaving a scar called the hilum. The ovule also begins dessication (process of drying out), and the integuments harden to become the seed coat.
Term
What is in the pelvis area of the bean seed?
Definition
The area where the radicle will emerge, the hilum, and the micropyle.
Term
How have mutations helped us understand embryo development?
Definition
disabling certain genes has cause some things not to develop. This shows us what genes control what phenotypes in embryo development.
Term
How are mutant plants created?
Definition
They are exposed to a chemical mutagen, then selected based on what they can show.
Term
What makes up the seed coats?
Definition
Sclerids
Term
What does the plumule become in a grain?
Definition
the young leaves
Term
What is the function of the coleoptile?
Definition
To protect the scutellum and the young leaves
Term
What is the scutellum?
Definition
The cotyledon of a grain
Term
What is the middle of the grain embryo called?
Definition
The mesocotyl
Term
What does the coleorhiza do?
Definition
Provides additional protection for the root cap.
Term
What is the first structure to emerge from the seed during germination?
Definition
Radicle
Term
How much of the whole weight of the seed is water? Why?
Definition
5-10 percent. Because being in a desiccated state allows the embryo to stay dormant.
Term
What are the steps in seed germination?
Definition
imbibition of water - embryo activation - slower water uptake - mobilization of stored food - radicle emergence - est. plant body
Term
what hormone breaks down the endosperm, what produces it, and what causes this structure to produce it?
Definition
Amylase is produced by alurone. caused by inbibition of water.
Term
what are some examples of epigeal seed germination?
Definition
Onion
Term
What are some examples of hypogeal seed germination
Definition
Peas, corn
Term
How long are seeds usually viable?
Definition
about 10 years
Term
What is the record for seed dormancy?
Definition
1000 years
Term
How can the embryo stay dormant?
Definition
it reduces it's metabolism until conditions are right. (Light, water, temperature)
Term
What 3 things cause seed dormancy?
Definition
Seed is still immature, the seed coat is impermiable to water, not enough oxygen is available.
Term
Why are some seeds dormant?
Definition
they need the right conditions to grow, or they need to be dispersed to another location first (by animals).
Term
How long ago did the first photosythetic organisms appear?
Definition
3.6 billion years ago
Term
When did the first water splitting photosynthetic cells arise?
Definition
About 2.5 billion years ago.
Term
when did aerobic respiration arise and why?
Definition
about 2 billion years ago owing to the abundance of oxygen in the air due to water splitting photosynthesis producing oxygen.
Term
When did eukaryotic cells arise?
Definition
1.6 billion years ago.
Term
when did the first multicellular life arise?
Definition
about 1 billion years ago.
Term
give the major events in evolutionary history in order.
Definition
formation of the earth - formation of the ocean - first prokaryotic cells - first photosynthetic organisms - first h20 splitting photosynthetic organisms - aerobic respiration - eukaryotic cells - multicellular life - vertbrates
Term
during what era did photosynthesis arise?
Definition
the precambrian era
Term
what is photosynthesis?
Definition
process that converts solar energy into chemical energy.
Term
what is the equation for photosynthesis?
Definition
H20 + CO2 + LIGHT ---> C6H1206 + 02 + H20
Term
What is the respiration equation?
Definition
C6H1206 + 02 ---> C02 + H20 + ENERGY
Term
what do we get out of the light reaction?
Definition
ATP and NADPH
Term
what do we get out of the calvin cycle?
Definition
carbohydrates (C3H603 - TRIOSE)
Term
What is visible light a tiny part of?
Definition
The electromagnetic spectrum
Term
what are the structural components of a chlorophyll molecule?
Definition
A porphyrin ring connected to a long phytol tail.
Term
What is an absorption spectrum?
Definition
The characteristic spectrum of absorption for each pigment.
Term
what is an action spectrum?
Definition
a combination of the pigments in a plant that shows what colors are absorbed most by the plant.
Term
what molecules in the plant trap the energy from sunlight?
Definition
pigments like chlorophyll, xantophylls, caratoids, ect.
Term
in what cellular structures does the energy trapping take place?
Definition
Photosystems.
Term
what are the antenna pigments? where are they located??
Definition
Antenna pigments are pigments that collect all of the energy from sunlight and funnel it to the center of the photosystem.
Term
What is the reaction center?
Definition
The center of the photosystem. It has 2 special chlorophyll molecules that collect the energy from the antenna pigments.
Term
why are antenna pigments necessary to start the photosynthesis process?
Definition
Because they only collect a little bit of energy from sunlight, not enough to start photosynthesis. the collected efforts of all the photosystems allow for photosynthesis to take place @ rxn center.
Term
photosystem II is also called
Definition
P680
Term
What molecule is the first electron acceptor in PSII? second? third?
Definition
Pheophyton -> plastoquinone -> Cytochrome B6f complex
Term
How do hydrogens get into the thylakoid lumen?
Definition
The splitting of H20 puts hydrogens there, but also cytochrome B6f pumps hydrogens into the thyladoid lumen.
Term
name all electron acceptors in light dependent reaction in order.
Definition
P680 - pheophyton - plastoquinone - b6f - plastocyanin - P700 - mod. chlorophyll a - phylloquinone - iron sulfur proteins - ferrodoxin - flavoprotien - NADP+ reductase
Term
what happens in cyclic electron transport?
Definition
PSI (P700) - iron sulfur proteins - ferredoxin - B6f - plastocyanin - PSI - (rpt)
Term
what are the differences between cyclic and noncyclic electron transport? (on next exam)
Definition
Cyclic only produces ATP using only PSI. There is no NADP+ synthase. No water will be split, the electrons are reused by PSI.
Term
How do photosynthesis inhibiting pesticides work?
Definition
They bind to a protein in the electron transport chain. This blocks the energy transport leading to free radical production in such large amounts that the plant dies.
Term
what happens generally in C3 photosynthesis?
Definition
CO2 is captured and turned into 3 carbon sugars.
Term
What are the 3 steps of the calvin cycle? (C3)
Definition
1. Carboxylation
2. Reduction
3. Regeneration of 5C RuBP
Term
What is the carboxylation reaction and what facilitates this?
Definition
RuBP + CO2 --> 2PGA
RuBisCO Facilitates.
Term
What is the product of reduction of PGA?
Definition
6PGAL
Term
How many PGAL go to regerate the RuBP?
Definition
5
Term
What is the cost of reduction of PGA to PGAL?
Definition
ATP and NADPH
Term
What is the cost of regeneration of RuBP?
Definition
ATP
Term
Write the whole calvin cycle.
Definition
RuBP + CO2 -RuBisCO-> PGA -3PGA kinase (ATP)-> 1,3-biPGA -PGAL dehydrogenase (NADPH)-> (6)PGAL (5) -ATP-> RuBP (rpt)
Term
write the overall equation for carbon fixation
Definition
3CO2 + 9ATP + 6NADPH + 6H+ --> PGAL + 9ADP + 8P + 6NADP+ + 3H20
Term
by what kind of metabolism does the plant make sugar from PGAL?
Definition
Anabolism
Term
what other useful molecules can be created from derivations of calvin cycle compounds?
Definition
Lipids, Acetyl CoA, Polysaccharides, and Nucleic Acids
Term
what is sucrose?
Definition
Half glucose half fructose.
Term
what sugar is transported in the phloem??
Definition
Sucrose
Term
What does PGAL turn into to be stored?
Definition
Starch
Term
what cells is sucrose transported to for transport?
Definition
Mesophyll - bundle sheath cell - phloem parenchyma cell - companion cell - seive tube
Term
how is the sucrose transported from the source to the sink once it is in the phloem?
Definition
The vessel elements right next to it are full of water and as sucrose is added to the seive tube, the higher concentration of substrate causes osmosis to place more water into the seive tube which forces the sucrose down to the sink (gravity).
Term
why is photorespiration bad?
Definition
The toxic compound phosphoglycolate is produced and processing it costs ATP and NADPH, and releases CO2.
Term
What organelles does photorespiration require?
Definition
it involves 3 organelles - the chloroplast, the peroxisome, and the mitochondria.
Term
What is phosphoglycolate eventually turned into?
Definition
It is turned into PGAL and entered into the calvin cycle.
Term
What anatomical adaptations do plants have to adapt to hot and dry environments?
Definition
Thick waxy cuticle and bulliform cells to close their leaves.
Term
what are two adaptations to photosynthesis in hot and dry environments?
Definition
C4 and CAM photosynthesis
Term
Most C4 plants are...
Definition
Monocots (80%)
Term
Why is C4 photosynthesis so named?
Definition
Because PEP (3C) combines with CO2 to form a 4 carbon oxaloacetate in the mesophyll cells
Term
What does the mesophyll cell store the 4C oxaloacetate as? (c4 photosynth)
Definition
Malate
Term
When the CO2 first enter the mesophyll cell in c4 photosynthesis, what happens?
Definition
CO2 combines with H20 to form HCO3 which then combines with PEP to form oxaloacetate.
Term
The oxaloacetate in C4 respiration can be turned into 2 things, what are they?
Definition
Malate
Aspartate
Term
Why does the plant bother doing C4 respiration?
Definition
There is too much oxygen in the plant because it lives in a hot and dry environment so it can't open its stoma during the day without losing water. To avoid photorespiration it transports malate to the bundle sheath cells then catabolizes the malate to form CO2 which enters the calvin cycle and doesn't form toxic phosphoglycolate.
Term
what sort of electron transport chain does the chlorophyll in the bundle sheath cells do? Why?
Definition
Cyclic electron transport in the bundle sheath cells because if they did non-cyclic they would create oxygen and ruin the oxygen free environment of the bundle sheath cells.
Term
where is all the RuBisCO in C4 plants?
Definition
The bundle sheath cells.
Term
Why did C4 plants first evole from C3 plants?
Definition
because 50-60 million years ago there was a decline in atmospheric CO2 and increase in O2 this led to a strong selective advantage for C4 photosynthesis.
Term
T/F C4 plants are more efficient at using nitrogen and water.
Definition
True
Term
Where do C4 plants do best?
Definition
Hot, nutrient deficient areas.
Term
what are some examples of CAM plants?
Definition
Cacti succulents and pineapples
Term
How does a CAM plant work generally?
Definition
it fixes the carbon to a 4 carbon acid during the night then uses that CO2 to do the calvin cycle during the day.
Term
what is different about the C4 leaf anatomy compared to C3?
Definition
The mesophyll cells are all arranged around the bundle sheath cells, and don't have any chloroplasts. The bundle sheath cells are also thicker.
Term
What two factors increase photosynthetic rate in low concentrations, but too much decreases the photosynthetic rate?
Definition
Water
Heat
Term
What is the equation for photorespiration?
Definition
RuBP + O2 --> PGA + Phosphoglycolate
Term
What basic steps happen in the plant to process phosphoglycolate?
Definition
1) In the chloroplast the phosphoglycolate is dephosphorylated and turned into glycolate
2) In the peroxisome the glycolate is oxidized via hydrolysis and turned into glycine
3) In the mitochondria the glycine is turned into serine producing NADH and CO2
4)in the peroxisome the serine is turned into glycerate - uses an NADH
5)In the chloroplast the glycerate is phosphorylated into a phosphoglycerate (PGA) and entered into the calvin cycle
Term
how does the peroxisome deal with the fact that hydrogen peroxide (H2O2) is created during the processing of phosphoglycolate?
Definition
It uses catalase to convert the H2O2 into water and oxygen.
Term
what is needed to turn serine into glycerate?
Definition
NADH (and glyoxylate)
Term
how does a thick cuticle help the plant adapt to hot and dry environment?
Definition
1)reflects the solar radiation
2) prevents water loss.
Term
You see a cross section and the plant has large bundle sheath cells. What does this indicate?
Definition
It operates by C4 photosynthesis
Term
how is oxaloacetate made, where is it made, and in what kind of plant?
Definition
Oxaloacetate is made from a anabolic reaction of bicarbonate ion (HCO3-) and a phosphoenolpyruvate (PEP) in the mesophyll cells of plants that undergo C4 photosynthesis.
Term
What enzyme facilitates the conversion of PEP to oxaloacetate?
Definition
PEP carboxylase
Term
Why is the process of CAM respiration similar to C4?
Definition
Because Phosphoenolpyruvate and HCO3- still combine to form oxaloacetate at night. the oxaloacetate is then turned into malate and stored in the vacuole for usage during the day.
Term
What can malate be turned into in CAM plants? When does this happen?
Definition
Malate can be turned into pyruvate (3C) and CO2 which is used in the calvin cycle.
Term
Which process has the highest photosynthetic rate?
Definition
C4 has the highest photosynthetic rate
Term
Which process has the lowest photosynthetic rate?
Definition
CAM plants
Term
What is different about the CAM plant's cells?
Definition
They have very large vacuoles.
Term
When are the stoma open in C4 and C3 plants?
Definition
Stoma are open during the day and closed at night when there is no light to do photosynthesis.
Term
What sugar needs to be synthesized for transport in the phloem?
Definition
Sucrose
Term
How does the plant break down sugars to obtain energy?
Definition
Throught the respiration process.
Term
Where is starch accumulated after the calvin cycle?
Definition
The chloroplasts.
Term
What is used to start the respiration process in plants?
Definition
Pyruvate
Term
T/F When a chlorophyll molecule at the reaction center of a photosystem absorbs sufficient energy, it is oxidized by loss of an electron.
Definition
TRUE
Term
The Calvin cycle produces a compound that is used to synthesize other carbohydrates such as sucrose and starch. The name of this compound is:
Definition
Phosphoglyceraldehyde or Glyceraldehyde 3-phosphate
Term
Photorespiration is favored by....
Definition
A hot dry environment.
Term
Where does oxygen come from?
Definition
The dissociation of H20 molecules during the light dependent reaction of photosynthesis.
Term
What are the photosynthesis molecules arranged on the periphery of the photosytem called? What are they made of?
Definition
Antenna molecules. Made of chlorophyll.
Term
Where is the electron transport chain located? This takes place during the ____ of photosynthesis.
Definition
In the thylakoid membrane. This takes place during the light dependent reactions of photosynthesis.
Term
What is PSII's electron acceptor?
Definition
Pheophytin
Term
What happens during carboxylation?
Definition
The Rubisco creates PGA (Phosphoglycerate) from CO2 and Ribulose 1,5-biphosphate.
Term
Photorespiration occurs when rubisco combines with oxygen to produce glycolate. Why is photorespiration is a wasteful process?
Definition
because energy is used to break down glycolate and CO2 is produced.
Term
n the C4 pathway, what happens to the CO2 formed when malate is decarboxylated in bundle-sheath cells?
Definition
It enters the calvin cylce
Term
After a chlorophyll molecule is “hit” by a photon, which of the following occur?
Definition
DOnation of a ectron from chlorophyll to an electron acceptor.
Term
where does carbon fixation take place in C3 photosynthesis?
Definition
The stroma.
Term
What is the most promising approach to solving the world's food problems?
Definition
Improving the existing crops.
Term
______ is a particularly salt-tolerant plant that may prove useful in producing salt-tolerant hybrids.
Definition
Solanum Cheesmanii
Term
Unlike cereals, the seeds of grain amaranths have a high content of:
Definition
Lysine
Term
What percentage of available prescription drugs come from plants?
Definition
25%
Term
T/F Chili peppers originated in the OLD world
Definition
FALSE The NEW world.
Term
The result of double fertilization in angiosperms is:
Definition
One zygote and endosperm tissue
Term
In a grass embryo, the coleorhiza encloses the:
Definition
Radicle
Term
Is periderm present in the torpedo stage of embryo development?
Definition
No.
Term
The fruit characteristic of the pea family is a(n):
Definition
Legume
Term
What is a follicle?
Definition
A fruit formed from one embryo that is dehiscent along one seam
Term
What is charactaristic of drupes?
Definition
A stony endocarp
Term
What is moore's law?
Definition
The density of transistors on a microchip will double every 18 months.
Term
What does Elias Greenbaum want to do to create better and more efficient microchips?
Definition
Use spinach leaves
Term
How small are photosytems?
Definition
a million times smaller than a grain of sand.
Term
What is the first electron acceptor in PSI?
Definition
Phylloquinone.
Term
how long does the light dependent reaction take?
Definition
a few billionths of a second
Term
What did greenbaum was the most important thing about PSI? What did this remind him of? Why?
Definition
THe most important thing about PSI is that it is structured in such a way that it prevents the electron from going back to photosystem II. This reminded Greenbaum of a semiconducting diode because the electrons can only move in one direction.
Term
What is rectification?
Definition
Converting alternating current (AC) to direct current (DC)
Term
What does a semiconducting diode do?
Definition
It is a rectifier - turns AC to DC.
Term
What are logic gates and how are they made?
Definition
Logic gates are digital switches that carry out electronic calculations. to make one you must connect many semiconducting diodes.
Term
how big are Photosystem's? How much smaller are they than the current smallest semiconducting diode?
Definition
7 nanometers in diameter. more than 20 times smaller than the current smallest semiconducting diode.
Term
Why cant you just pluck up the photosystems and arrange them to create logic gates?
Definition
Because they are delicately folded proteins that can easily be disrupted. If they are disrupted the reaction center does not work. Also they are in the thylakoid membranes inside of chloroplasts inside of plant cells, getting them out is very hard.
Term
why did greenbaum choose spinach?
Definition
. "Spinach is readily available and has soft, tender leaves - that makes it much easier to extract the reaction centres."
Term
How do they prepare the spinach? What are the challenges with this?
Definition
They blend the spinach with plenty of ice to keep it cold because the enzymes released during blending could break down the reaction centers.
Term
How does greenbaum extract the chloroplasts from the plant cell?
Definition
He crushes up the cells then runs them in a centrifuge to seperate the chloroplasts from the crushed plant matter.
Term
How does greenbaum extract the reaction centers from the chlorophyll?
Definition
He uses a detergent that chisels out the reaction centers which can then be seperated by chromatography.
Term
How did greenbaum make his spinich diode once he had the reaction centers separated?
Definition
He immersed gold plated wafers in a suspended solution of reaction centers then looked at the wafers under a scanning tunnel microscope.
Term
How did greenbaum test his diodes. What problem did he find? What did he do about it?
Definition
He applied a voltage between the microscope tip and the wafers and measured the electrical properties. He found that the reaction centers only worked when they were pointing upwards. He coated the gold plates with mercaptoacetic acid to give them a negative charge. This caused the reaction centers to stand up horizontally. He then treated the gold plate with 2-mercaptoethanol which caused them to stand up vertically.
Term
THe reaction centers can't all be jumbled up to make a diode. How must they be arranged?
Definition
They must all be pointing upwards and they must also be connected to form circuits!
Term
How does greenbaum plan to connect the reaction centers into a circuit?
Definition
our goal is to use carbon nanotubes and organic molecular wires which would transport charge
Term
What property of the reaction centers could be the answer to the problem of how to connect the reaction centers into circuits?
Definition
The reaction centers are slightly positive on each end. If the nanotubules were given a negaive charge they could attach to the biodiodes.
Term
What is a huge problem for the diodes once they are connected and operational? How can they solve this?
Definition
If the diodes are exposed to air the reaction centers oxidize which cause them to stop working. Seal the diodes in oxygen free boxes.
Term
besides being a new semiconducting diode, what other property/function does the diode have? What could this be used to do?
Definition
Each reaction center is essentially a small solar cell. They produce one volt potential when hit with a lazer. The electron leaves one side and go around the circuit. Make computer power supplies that run on sunshine.
Term
junipers and yews are examples of conifers without...
Definition
cones
Term
leaves in conifers are either ____ or _____.
Definition
needles or scales
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