Download 9.2.11 Translocation Study Guide

9.2.11 Translocation Study Guide
Part 1: Read for Understanding
Instructions: Read pages 254-256, and then address the learning objective below.
• 9.2.11 Ouline the Role of Phloem in Active Translocation of Sugars (sucrose) and amino acids from source
(photosynthetic tissue to storage organs) to sinks (fruits, seeds, roots)
Part 2: Guided Notes
Instructions: Open the 9.2.11 Translocation PowerPoint Notes on the IB2 Biology Moodle Page, and fill in the blanks
• Movement from Source to Sink
– A process of
moves sugars through a plant from
a source to a sink.
– A
is any cell in which sugars are produced by
photosynthesis.
– A
is any cell where the sugars are used or stored (fruits,
roots, seeds).
• Vascular Tissue: PHLOEM Tissue
– Phloem Cells are
.
–
lacks nucleus & cytoplasm
– Sieve tube elements are connected to each other via
.
– Sieve plates have holes which allow movement of water and dissolved organics molecules
–
has nucleus and dense cytoplasm
– Companion cells are attached to sieve tube element via
.
• Phloem Translocation Summary
• 1.
moves the organic molecules (sugars, amino acids) from their
through the tube system of the phloem to the
. Phloem vessels still have cross walls called sieve plates that contain pores.
• 2.
actively (active transport) load sucrose (soluble, not
metabolically active) into the phloem.
• 3. Water follows the high solute in the phloem by
.A
positive pressure potential develops moving the mass of phloem sap forward.
• 4. The sap must cross the
. Current hypothesis do not account for this
feature.
• 5. The phloem still contains a small amount of cytoplasm along the walls but the organelle content
is greatly reduced.
• 6.
actively unload (ATP used) the organic
molecules
• 7.
are stored (sucrose as starch, insoluble) at the sink. Water is
released and recycled in xylem.
Translocation in Greater Detail
STEP 1
• Sugars produced during photosynthesis (
) are actively (using ATP) pumped into the
.
•
This loading of sugar is accomplish by
.
STEP 2
• As sugar concentrations increase in the sieve tubes, water from the xylem moves into the sieve tube
by
.
STEP 3
• This movement of water causes a
results in
•
This movement does not require energy.
STEP 4
• The
tube at the sink.
• This removal of sugar is accomplished via
to build up in the sieve tube that
.
by the removal of sugar from the sieve
.
•
The sugar is converted into
in insoluble and exerts
.
STEP 5
• Xylem
the
the relatively pure water by carrying it from
.
Summary of Transport in Plants
• 1. Source produces
.
• 2. Glucose from photosynthesis produced
• 3.Glucose converted to
for transport
• 4.
actively loads the sucrose
• 5. Water follows from xylem by
.
• 6. Sap volume and
to give Mass flow
• 7. Unload the organic molecules by the
• 8. Sucrose stored as the
.
• 9. Water that is released is picked up by the
.
• 10. water recycles as part of transpiration to re supply the sucrose loading
Part 4 Practice Questions
.
Part 3: 9.2.11 Practice Questions