1' Starchsucrose partitioning

1
Topics since the last exam. Note only 1- 4
below are covered on this review. Disclaimer
the test may include questions and concepts not
presented in this review (although this is a very
good place to start.)

• 1. Starch/sucrose partitioning
• 2. The ecology of photosynthesis
• 3. Phloem translocation
• 4. Respiration
• 5. Nitrogen assimilation and N-fixing symbiosis
• 6. Secondary chemistry I, II, III.

2

• Starch - sucrose partitioning
• What are the major storage and transport
  carbohydrates in plants?
• How is starch-sucrose partitioning regulated?
• Where does starch accumulate?

3

• 2. Ecology of photosynthesis
• Define water use efficiency
• Explain how WUE differs among C3, C4, and CAM
• plants and why.
• How do sun and shade leaves differ anatomically
  and physiologically?
• How does the chlorophyll/rubisco ratio differ
  between sun and shade leaves? Explain in terms of
  the limiting factor for photosynthesis in each
  case.
• Draw light response curves for sun and shade
  leaves and note key differences.

4

• 3. Phloem translocation
• List four compounds that are translocated in the
  phloem.
• Define source and sink as weve used the
  terms
• to understand the direction of phloem
  translocation.
• How do sieve tube elements differ from tracheary
  elements?
• Draw a figure that illustrates the Münch
  pressure-flow model
• of phloem translocation from a source to a sink.
• Give representative values for the components of
  water
• potential in the phloem and xylem.
• Where is energy involved in phloem translocation?
• Be able to interpret 14C autoradiograms as weve
  used them
• for tracing the movement of photoassimilate.

5
4. Plant respiration What are the major products
of respiration? What is the major byproduct of
respiration that is often measured to understand
respiration rate? Write a balanced equation for
the complete oxidation of one sucrose molecule.
What are the major stages of respiration? Which
can proceed in the absence of oxygen? Explain
what the alternative oxidase is, how it affects
respiratory energy production, and what its
function may be in plants. Draw a figure
illustrating how the p.m.f. and ATP production
are oriented across the mitochondrial membrane
system.