Acquisition Of Water And Minerals Flashcards
What is the need for transport
As land plants evolved, competition for light, water and nutrients increased. Simple ways of transportation became inadequate, leading to evolution of vascular tissues .
Methods of water and solute movement
- Active transport
- Passive short distance transport
I. Diffusion
II. Osmosis
III. Imbibition
IV. Facilitated diffusion - Passive long distance transport
I. Bulk flow
What is active transport
Movement of some materials across membrane take place using ATP. This process is called active transport.
What causes diffusion
Thermal energy in molecules due to their constant motion
Define diffusion
In the absence of other forces the movement of molecules of a substance from a place where it is more concentrated to a place where it is less concentrated due to random motion of molecules
True or false
Movement of a molecule is random, movement of a population is directional
True
What are the features of diffusion
- Takes place according to a concentration gradient
- Spontaneously
- Don’t use metabolic energy
Can diffusion take place across the membrane
Yes. If the membrane is permeable to the mooecules
What is osmosis
A special type of diffusion of free water molecules across a selectively permeable membrane.
What is free water
Water molecules that are not bound to solutes or surfaces
What is imbibition ?
The physical absorption of water molecules by hydrophilic materials
What is facilitated diffusion?
Movement of water and hydrophilic solutes across the membranes passively with the help of transport proteins that span the membrane.
Features of transport proteins
- Very specific.
- Movement along concentration gradient
- Passive movement
What is bulk flow
The movement of liquid and materials (entire solution) in response to pressure gradient
Bulk flow direction
Always flows from higher pressure to lower pressure region
