Study questions for Botany Topics: photosynthesis, xylem and phloem flow

I. Chapter 10 Energy metabolism: photosynthesis

1. For the following terms, be able to EXPLAIN what the term means and the process it represents. DO NOT MEMORIZE the definition in the back of the text. Really understand the importance of what the term represents, the stages or anatomy involved and so on.

• Anabolic reactions
• ATP synthase (not just what it produces but how it produces)
• C3 ( Calvin/Benson cycle).. know the steps involved, what it is responsible for producing, what components are involved
• C4 metabolism..know the steps involved, what it is responsible for producing, what components are involved
• chemiosmotic phosphorylation
• chlorophyll: the different types and each of their roles
• Crassulacean acid metabolism ( CAM) . know the steps involved, what it is responsible for producing, what components are involved
• cyclic electron transport
• cytochromes roles, different types
• electron transport chain... good review for all of us
• gluconeogenesis
• light compensation point
• light dependent reactions
• noncyclic electron transport . know the steps involved, what it is responsible for producing, what components are involved
• oxidative phosphorylation
• 3-phosphoglyceraldhyde
• photon
• photosystem I vs. photosystem II . know the steps involved, what it is responsible for producing, what components are involved
• pigment what is it, what does it do, differences between resonance and other means of giving off electrons or the energy absorbed
• quality of light
• quantum
• reaction center
• reduced compound
• Ribulose 1,5 biphosphate
• RUBISCO
• stroma reactions
• z-scheme

II. 1. in photosynthesis, what is the ultimate source of electrons? what are the benefits of this molecule in terms of its toxicity and cost of the plant to obtain it?

2. Describe the absorption spectrum of chlorophyll a vs. b. How do they match the action spectrum of photosynthesis? Why don't plant contain a variety of pigments that would absorb all visible wavelengths, so they could use the sun's energy more efficiently?

3. Name the electron carriers that transport electrons from photosystem II to PS I. Which ones contain metal metal atoms and which do not? why don't they all?

4. When electrons are removed from water, protons are liberated. Does this occur in the stroma or inside the thylakoid lumen? Can protons move directly across the membrane? Describe the chemiosmotic mechanism of ATP synthesis in chloroplasts?

5. What is the the acceptor of CO2 in the C3 cycle? what enzymes catalyze the reaction and what is the product? why is the acceptor evolutionary so conservative? is it similar to our own hemoglobin? explain

6. Imagine an environment where CO2 was depleted. Would RUBP carboxylase function? how so? would NADP be in the reduced or oxidized form? Given the opposite is occurring in today's atmosphere ( high loads of CO2, should plants be photosynthesizing more? are there other limiting factors?

7. In a C4 plant, where is PEP carboxylase located? where is RUBP carboxylase located? how does this differ in a CAM plant?

Topic: xylem and phloem transport Chapter 12

1. For the following terms, be able to EXPLAIN what the term means and the process it represents. DO NOT MEMORIZE the definition in the back of the text. Really understand the importance of what the term represents, the stages or anatomy involved and so on.

• active transport
• callose
• cavitation
• cohesion-tension hypothesis
• cohesive
• diffusion
• embolism - how often do they occur? how are they repaired?
• incipient plasmolysis
• long distance vs short distance transport
• matric potential
• molecular pump
• osmosis
• P-protein and P-protein plug
• plasmolysis
• pressure flow hypothesis
• pressure potential
• selectively permeable membrane
• sink/source
• water potential

2. What are the components of water potential? describe how the structure of plant walls, vacuolar contents, etc. helps to increase or decrease it.

3. In a beaker of pure water, what is the water potential? does water potential become more positive or more negative as yo add solute to it? Put pressure on it? add it to dry clay? add acid to it? In each case which water potential component is changing?

4. In each of the following pairs, choose the one that would probably have the more negative water potential and explain why:

• cell of a wilted leaf --- cell of a turgid leaf
• guard cell of an opening stomata -- regular epidermal cell
• root cortex cell -- moist soil
• phloem cell being loaded with sucrose --leaf chlorenchyma cell

5. Describe the cohesion- tension model of water movement xylem. Would the weight of water be more of a problem in a tree or a stolon? why?

6. How does a 300 foot tree as with the redwoods get the water up there in spite of the weight of a 300 ft column of water?

7. Follow a sugar molecule just produced in a mesophyll cell, and describe all the steps involved in getting it down to be stored in a root.

8. Should transport of sugars be more problematic during dry periods for a plant? explain? if so, how would a plant get around an accumulation of sugars in the leaf?

9. Explain how the older version of xylem flow has been modified? see notes.