Exam 1 Flashcards
Which of the following statements(s) is/are true about the plant cell wall?
- Cellulose and hemicellulose are linear, unbranched polymers, but pectin is different because it is a branched polymer.
- The orientation of the microfibrils determines the direction of growth of plant cells, and in stem and root cells the microfibrils are present in a random orientation.
- In the xylem the secondary cell wall can get so large that it kills the plant cell.
- Both the primary and secondary cell wall have very limited permeability and only allow water, ions and gases to pass across the cell wall.
- The secondary cell wall occurs outside the primary cell wall in xylem tissue but inside the primary wall in all other cells of the plant.
- False
- False
- True
- False
- False
The _____________ is the region of the plant that is enclosed within the cell membrane, and the _________________ is the cell wall region of the plant. The _____________ is part of the plasmodesmata and is also considered part of the _________________
symplast, apoplast, desmotubule, symplast
The apoplast includes:
the middle lamellae, primary cell wall, secondary cell wall
Which of the following statement(s) is/are true about the vacuole?
- The tonoplast contains an ATPase that uses the energy of ATP to build a proton gradient, and the energy in the proton gradient is used for the transport of many different compounds into the vacuole.
- The vacuole is in osmotic equilibrium with the cytoplasm.
- The pH of the vacuole is usually higher than the cytoplasm due to the accumulation of protons inside the vacuole.
- Storage of amino acids, ions, and pigments is one of the functions of the vacuole.
- The vacuole is always a major portion of the volume of all plant cells.
- True
- False
- False
- True
- True
Which of the following statement(s) is/are true about the vacuole?
- ATP is used to produce a proton gradient across the vacuole with the inside of the vacuole being a lower pH than the cytoplasm.
- The proton gradient that exists across the tonoplast can be used to transport cations into the vacuole.
- The pH gradient that exists across the tonoplast can be used to transport small molecules like glucose into the vacuole where they can accumulate to a higher concentration than in the cytoplasm.
- As the ion concentration in the vacuole increases there is a net movement of water from the vacuole into the cytoplasm due to osmosis.
- Chlorophyll usually accumulates in the vacuole.
- True
- True
- False
- True
- False
Fill in the blanks based on the equation given below.
CO2 + H2O ↔ C(H2O) + O2
When this equation goes from left to right the process is called _________________, and when the equation goes from right to left the process is called ____________________. The O2 that is produced comes from the ______________.
photosynthesis, respiration, H2O
Which of the following statement(s) is/are true about light?
- The photon is the basic unit of light energy, and the longer the wavelength of the photon the lesser the energy.
- The excited state of a molecule can only be produced when a photon with a specific energy is absorbed by that molecule.
- The excited singlet state of a molecule can be attained by a series of very close wavelengths and that is why absorption spectra are curves and not lines.
- When a photon is absorbed by a molecule the molecule is said to be in an excited state, and that excited state is frequently dissipated by loss of heat.
- The units micro-Einstein/square meter/sec (uE/m2/sec) do not give any information about the energy of the light but only refer to the number of photons.
- True
- True
- True?
- True
- False?
Which one of the following statements is true about energy production in the chloroplast?
a. The Q Cycle is a mechanism to increase the number of protons that are transported across the thylakoid for every electron that moves through photosynthetic electron transport.
b. Cyclic electron transport produces both extra ATP and extra NADPH.
c. Blue light is energetically more efficient than red light because a larger percentage of its energy is converted into ATP and NADPH.
d. During photosynthetic electron transport, protons accumulate in the stroma and this proton gradient is used for the production of ATP.
e. When the level of NADP+ in the chloroplast is low, photosynthetic electron transport stops.
A or C?
Which of the following statements are true about chlorophyll?
- An atom of Mg+2 is important in order for chlorophyll to absorb visible light.
- Chlorophyll b must be present in all plants in order for them to photosynthesize.
- The cyclic tetrapyrrole portion of the chlorophyll molecule is embedded in the thylakoid membrane due to its hydrophobic nature.
- A relatively small difference in chemical structure results in a difference in light absorption between chlorophyll a and chlorophyll b.
- Chlorophyll can transfer excess energy to zeaxanthin.
1, 4, 5
Which of the following findings of the Emerson-Arnold experiment were surprising to Emerson and Arnold?
- O2 was produced in response to flashes of light.
- The amount of O2 produced showed saturation at high flash energies.
- One O2 was produced by 2500 chlorophyll molecules.
- One O2 was produced by 8-10 photons.
4
Which of the following are differences between Photosystem II and Photosystem I?
- The amount of chlorophyll b is different in each photosystem.
- The reaction center is different for each photosystem.
- The electron donor for each photosystem is different.
- Their location in the thylakoid is different.
- Only Photosystem II requires light.
1, 2, 3, 4
Which of the following statement(s) is/are true about photosynthetic electron transport?
- The Emerson-Arnold experiment and the Emerson Enhancement Effect were important experiments in understanding the role of chlorophyll in photosynthesis. These experiments led to the development of the concept of Photosystems.
- The Light Harvesting Complexes act as antennae for collecting light, and they can transfer the absorbed light to the photosystems. When Photosystem II receives too much light the Light Harvesting Complex dissociates from Photosystem II to reduce the energy that is going to that photosystem.
- ATP and NADP+ are two important compounds that are produced as a result of photosynthetic electron transport. (False, ATP and NADPH)
- Alternate photosynthetic electron transport pathways exist to help provide extra ATP and NADPH, and two of these pathways are cyclic electron transport and pseudocyclic electron transport.
- Water is the ultimate source of electrons used to reduce NADPH to NADP+.
1, 2, 4, 5
Which of the following statement(s) is/are true about photosynthetic electron transport?
- When the NADP+ concentration is low, non-cyclic electron transport will be the preferred electron transport pathway. (false, cyclic)
- As a result of photosynthetic electron transport, a pH gradient is established across the thylakoid with the stroma having a much higher pH than the inside of the thylakoid.(false, lumen lower than stroma)
- Both cyclic photosynthetic electron transport and pseudocyclic photosynthetic electron transport are ways to produce extra NADPH without producing extra ATP. (False)
- Since blue light has more energy than red light, it is more efficient for the production of NADPH in the chloroplast. (False, red light more efficient 31%, blue is only 20%)
- The Emerson Enhancement Effect showed that a pH gradient can make ATP in the chloroplast. (False)
none of the above
Which of the following does not happen during cyclic photosynthetic electron transport?
a. ATP is produced; Photosystem I is fully active; light is absorbed
b. Photosystem II is fully active; O2 is reduced to hydrogen peroxide; NADPH is made
c. Photosystem I is fully active; NADP+ is reduced; light energy is utilized
d. light energy is utilized; PQ is involved; water is reduced
e. NADPH is made; a proton gradient is formed; the stromal Mg+2 concentration increases
c
