“Porins” are chemically?
Phospholipids
Carbohydrates
Proteins
Glycolipids
Related Questions
Which of the following is not correct regarding carrier molecules, involved in facilitated diffusion?
It helps in transporting molecules down the concentration gradient.
It is specific.
It is saturable.
It requires energy input.
What are the aquaporins in facilitated diffusion process?
Membrane proteins
Carrier proteins
Channel proteins
Carrier lipids
If two molecules A & B move in the same direction. This movement can be called
Antiport
Symport
Uniport
Guttation
If two molecules A & B move in the same direction. This movement can be called
Antiport
Symport
Uniport
Guttation
Facilitated diffusion differs from simple diffusion in that it:
Requires ATP
Moves substances against their concentration gradient
Requires membrane proteins
Occurs only in plant cells
What is mandatory in the process of facilitated diffusion?
Presence of concentration gradient
A carrier protein
A hydrophilic moeity
All of the above
Select the wrong statement regarding membrane channels
They are proteins
They are usually gated, i.e., may be open or closed
All ions pass through the same type of channel
They form a huge pore in the outer membrane of plastids, mitochondria and some bacteria
Which statement can be shared by facilitated diffusion and active transport?
Both need carrier transporter, which are sensitive to inhibitors that reacts with protein side chains
Energy is required by both the processes
No energy expenditure in these processes
Both use carbohydrates to move molecules
across the membrane
What happens to the rate of facilitated diffusion as the concentration of the transported molecule increases?
It increases linearly
It decreases
It reaches a maximum rate (saturation)
It remains constant
In a hypothetical cell, the facilitated diffusion of a solute 'Y' is observed to be significantly faster than predicted by simple diffusion models. However, the transport rate plateaus at high concentrations of Y. Which of the following is the MOST likely explanation for this observation?
The cell membrane is selectively permeable to Y.
The solute Y is transported via carrier proteins.
The solute Y is undergoing active transport.
The cell is modifying Y during transport.
