Lecture 27. Circulation and Gas Exchange in Plants Flashcards
How do animals prevent rupturing ?
They have semi permeable membranes and continually excrete soluble ions
What type of cell wall do plant cells possess ?
A relatively inelastic cell wall
What does high pressure exerted on the cell wall inhibit ?
The movement of water into the cell
What is turgor pressure ?
Hydrostatic pressure developed within the plant cell
What is the pressure in plant cell ?
1-2 mega pascals
What can japanese knotweed do ?
Grow through concrete
How does japanes knotweed work ?
Creates a huge rhizone network
What are the transport pathways ?
- Symplast
- Apoplast
- Gas filled intercellular spaces
What is a symplast ?
Interconnecting cytoplasm via plasmodesmata
What is an apoplast ?
Interconnecting cell walls
What type of pathway is apoplast ?
Low resistance pathway
What type of pathway is symplast ?
A high resistance pathway
What is a typical transpiration rate ?
4mm per second
What is movement of water molecules in response to /
Gradient in free energy
What is the chemical potential of water equal to ?
The chemical potential of water in an arbitrary reference state
What can effect chemical potential of water
- Concentration
- Pressure
- Electrochemical gradient
- Gravity
What is chemical potential of water ?
The amount of free energy in water in a given system
What is the equation of water potential ?
What is the water potential of pure water ?
Zero
What are xylem vulnerable to ?
Cavitation
