Chapter 10 Flashcards
1
Q
What properties does water have that makes it useful?
A
- metabolite for reactions e.g condensation/hydrolysis
- solvent (things dissolve into it)
- high heat capacity (buffers temp change)
- cooling effect (sweat)
- strong cohesion between molecules
2
Q
Where are inorganic ions found?
A
- cytoplasm
- body fluids
each ion has a specific role
3
Q
What is the function of the xylem?
A
transport water and dissolved minerals from roots up and out through plant
4
Q
What is the function of the phloem?
A
transport substances of photosynthesis around plant
5
Q
What is the cohesion tension hypothesis?
A
- water molecules stick together and travel together from roots up through plant until they evaporate at leaves
- water evaporating causes a ‘suction’ pulling more in from roots
6
Q
What is the mass flow hypothesis?
A
- sucrose produced = source
- take out = sink
- sucrose actively transported into phloem through sieve tubes at source (leaves)
- water potential decreases so water enters (osmosis) = higher pressure
- sink = sugars leave so water potential increases = water leaves and decreases pressure in sieve tubes
7
Q
How do ringing experiments provide evidence for the mass flow hypothesis?
A
- a ring of bark scraped away removing phloem
- sugar tries to be transported down stem but stopped by ring
- bulge of sugar forms above ring suggesting sugar moves down stem in phloem
8
Q
How does a tracers experiment provide evidence for the mass flow hypothesis?
A
- radioactive carbon dioxide
- bag over leaf and sealed
- carbon dioxide converted to glucose
- x-ray shows were radioactive material has moved to
