The movement of sugars - TRANSLOCATION
Terms in this set (22)
Translocation =
SOURCE =
SINK =
Transport of assimilates throughout the plant, in the
phloem tissue
Releases sucrose into the phloem
Removes sucrose from the plant
Sucrose entering phloem - ATP
Actively transport protons from cytoplasm into
is used by companion cells to...
surrounding tissue
Sucrose entering phloem -
Sets up a diffusion gradient, hydrogen ions diffuse
What does actively
back into the companion cells
transporting protons from the
cytoplasm into the surrounding
tissue do?
Sucrose entering the phloem -
Transporter proteins
what does the diffusion contain
through?
Sucrose entering the phloem -
Hydrogen ions to bring sucrose molecules into the
what do these proteins
companion cells
enable?
The movement of sugars - TRANSLOCATION
Sucrose entering the phloem -
Diffuse into sieve elements through plasmodesmata
what happens as the
concentration of sucrose
molecules builds up?
AT THE SOURCE -
AT THE SINK -
Sucrose reduces water potential, water moves in,
increases hydrostatic pressure
Converted into starch/respiration, reduces sucrose
concentration, move into surrounding cells
AT THE SINK - What does
Increases water potential, move into surrounding
sucrose molecules moving by
cells, reduces hydrostatic pressure
diffusion/active transport from
the sieve tube into surrounding
tissues do?
So... at the SOURCE =
So...at the SINK =
Mass flow =
Common sources =
Common sink =
How do we know that phloem
Water moves in, increases hydrostatic pressure
Water moves out, decreases hydrostatic pressure
Hydrostatic pressure gradient creates a flow of
water
Leaf, roots
Roots
Carbon, ringing results in sugars collecting, aphid
is used?
Why does ringing a tree result
Area above cut acts as a sink where sugars collect
in sugar
collecting? of sugars - TRANSLOCATION
The
movement
When fluid is collected from
Many sugars
the aphid, it contains...
Translocation - how do we
Mitochondria, metabolic poison, rate of flow
know that it needs metabolic
energy?
Translocation - how do we
know it uses this mechanism?
pH of the companion cells is higher than
surrounding, concentration of sucrose higher in
source than sink
Translocation - Evidence
Not all solutes move at the same rate, role of sieve
against this mechanism
plates is unclear