transportation Flashcards
(17 cards)
define assimilates
substances that have become a part of the plant
define sink
a part of the plant where those materials are removed from the transport system
what is an example of a sink and why ?
roots as they receive sugars and store them as starch
what can also happen to the source and why ?
in this example the roots can become a source as the starch may be converted back to sugars and transported a growing stem
–> due to the time of the year
define a source
a part of a plant that loads materials into the transport system
give an example of a source and why is it a source ?
leaves as they photosynthesise and sugars made are moved to other parts of the plant
define translocation
the transport of assimilates throughout a plant
where does translocation occur ?
in the phloem
how are assimilates made and where ?
they are substances made by the plant and are absorbed from the environment
what does assimilates include ?
sugars (sucrose) and amino acids
where is assimilates loaded and removed from?
they are loaded into the phloem sieve tube
how is sucrose loaded into the sieve tube ?
through an active process
draw a diagram of what happens during active loading with labelled diagrams
find drawn one or find in textbook
where is energy involved in active loading from ?
ATP in the companion cells
what is the energy used for ?
to actively transport hydrogen ions out of the companion cells
what happens while the energy is used and leads to ?
the concentration increases outside the (source) cells and decreases the concentration inside the companion cell
–> hence a concentration gradient
what happens to the hydr
