1、2016Plant Physiology Questions1. Please describe the major organelles of a plant cell and their functions.2. Please describe the different types of plastids and their features.3. Please describe the water movement pathways in plants.4. Please describe why nitrogen is important in plant life.5. Pleas
2、e describe the nitrogen fixation reactions in nature.6. Please describe your understanding of channel, carrier and pump in solute transport.6Three classes of membrane transport proteins:Channels and carriers can mediate the passive transport by simple diffusion or facilitated diffusion down the solu
3、tes gradient of electrochemical potentialChannel proteins act as membrane pores and their specificity is determined primarily by the biophysical properties of the channel. Carrier proteins bind the transported molecule on one side of the membrane and release it on the other side. Pumps are for activ
4、e transport using energy, usually from ATP hydrolysis, to pump solutes against their gradient of electrochemical potential.三种类型膜运输蛋白-通道、载体和泵。通道和载体可以介导溶质顺电化学势被动跨膜运输（简单或协助扩散）。通道蛋白作为膜上的孔道，它的特异性主要由通道的生物物理性质决定。载体蛋白在膜的一侧与被运输的分子结合并释放到膜的另一侧（不同类型的载体蛋白在图 6 . 11 详细描述）。初级主动运输由泵来完成，它直接利用 ATP 水解的能量，将溶质逆电化学势梯度泵出或泵
5、入。7. Please describe active transport, primary transport and secondary transport. 6Active transport: movement against a gradient of chemical potential, “uphill” needs “energy”. (often ATP)Primary active transport is coupled directly to a source of energy other than , such as ATP hydrolysis, an oxida
6、tion-reduction reaction, or the absorption of light by the carrier protein. These proteins are called pumps. Transport H+, Ca2+. Secondary active transport: carrier-mediated transport, is driven indirectly by pumps. For example, using proton motive force H+ gradient to drive other molecules moving a
7、gainst its concentration gradient. Secondary active transporters in plant harness energy from energetically downhill movement. Symport: both transported solutes move in the same direction across the membrane. Antiport: the two solutes move in opposite directions.在次级主动运输中，致电的 H运输产生的质子动力，用于驱动许多其他物质逆电化
8、学势梯度运输8. Please describe the events after a chlorophyll molecule absorbs a red photon, or a blue photon.9. Please describe the fate of light energy after it is absorbed by the photosynthetic pigments. 7ChlorophyllLight absorbed by the carotenoids is transferred to chlorophyll, thus they are called a
9、ccessory pigments. 10. Please describe the physiological functions of carotenoids.11. Please describe the relationship between light and plants (hint: from two perspectives). 12. Please describe the enhancement effect and the red drop effect.13. Please draw the detailed photosynthetic electron trans
10、fer chain. (hint: from H2O to NADPH)14. Please describe the xanthophyll cycle and its activation under high light.15. Please draw Calvin-Benson Cycle (C3 cycle). 816. Please describe the spatial (location) and temporal (time) types of C4 cycles. 17. Please describe the reactions that Ferredoxin (Fd)
11、 participates.18. Please draw the C2 cycle. 19. Please draw the TCA cycle. 20. Please describe the different zones and layers of the Arabidopsis shoot apical meristem.21. What is phytochrome? Please describe the phytochrome photoreversibility.22. Please describe the differences between a light-grown
12、 and a dark-grown di-cotyledonous plant.23. What processes do blue light regulates in plants? What are blue light receptors?24. Describe the environmental factors that regulate stomata aperture. What are the fundamental process controlling stomata aperture. (hint: consider water movement).25. When w
13、e are determining the steady level of a plant hormone in plant tissues, what are the factors that we should consider?26. Please describe the physiological functions of auxins.27. Please describe the auxin signal transduction pathway. (hint: what happens when there is no hormone, and there is hormone
14、, you can add information from related mutants). 28. Please describe the physiological functions of gibberellins.29. Please describe the gibberellins signal transduction pathway. (hint: what happens when there is no hormone, and there is hormone, you can add information from related mutants).30. Ple
15、ase describe the physiological functions of cytokinins.31. Please describe the two component signaling system and cytokinin signaling pathway.32. Please describe the physiological functions of ethylene.33. Please describe the biosynthetic pathway for ethylene.34. Please describe the ethylene triple
16、response, and how people have used the triple response in research to establish ethylene signal transduction pathways.35. Please describe the physiological functions of Abscisic Acid.ABA regulates seed development, seed and bud dormancy, germination, vegetative, growth, senescence, stomatal movement
17、, and stress responses;In seed development, ABA promotes synthesis of storage proteins and lipids, as well as specific proteins for desiccation tolerance;Seed dormancy and germination are controlled by the ratio of ABA to GA; ABA inhibits the GA-induced synthesis of hydrolytic enzymes in germinating
18、 seedsABAs effects on the growth of roots and shoots depend on the water status of the plant. ABA promotes root growth;ABA accelerates the senescence of leaves, increasing ethylene production and stimulating abscission;ABA accumulates in dormant buds, inhibiting their growth. ABA interacts with cyto
19、kinins and GAs.In response to water stress, ABA closes stomata by triggering a transient membrane depolarization, inhibiting the plasma membrane H+-ATPase, and causes a massive long-term efflux of K+ and anions from the cell, reducing guard cell turgor pressure36. Please describe the signal transduc
20、tion pathway of ABA.37. Please describe the factors that regulate plant senescence.(hint: consider different factors such as hormones)38. Please describe the physiological functions of brassinosteroids.39. Please describe the signal transduction pathway of brassinosteroids.40. When we are discussing
21、 plant hormones, we often use deficient, insensitive, resistant and constitutive. What are the biological meanings of these definitions? (hint: you can use examples).41. What factors regulate floral evocation?(hint: both endogenous and external)Endogenous factors:Circadian rhythms, phase change, hormones;External factors:Photoperiod (day length) and temperature42. Please describe the ABC model that explains Arabidopsis flower formation.
