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
Related Questions
A mutation in an aquaporin gene results in a non-functional protein. Which of the following cellular processes would be MOST directly affected?
Glucose uptake by muscle cells
Sodium transport across nerve cell membranes
Water reabsorption in the kidneys
Calcium storage in the sarcoplasmic reticulum
Choose odd one out w.r.t. facilitated diffusion.
Highly selective
Uphill and needs ATP
Transport achieves saturation
Affected by protein inhibitors
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
A researcher is studying facilitated diffusion of a novel solute 'X' across a cell membrane using an artificial lipid bilayer system. They observe that increasing the concentration of X on one side of the membrane increases the rate of transport, but only up to a certain point. Beyond this point, further increases in X concentration do not affect the transport rate. Which of the following BEST explains this observation?
The membrane has reached its maximum permeability for X.
The solute X is being actively transported at higher concentrations.
Saturation of the carrier proteins
The solute X is inhibiting its own transport through feedback regulation.
Which type of molecule is LEAST likely to cross a cell membrane by simple diffusion?
Small, nonpolar molecule
Small, polar molecule
Large, polar molecule
Small, uncharged molecule
Which of the following feature is not related to facilitated diffusion?
Transport protein required
Along the concentration gradient
Require the energy in the form of ATP
Can respond to inhibitors
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
Water channels are made up of how many different types of aquaporins?
Eight
Four
Five
Twenty
“Porins” are chemically?
Phospholipids
Carbohydrates
Proteins
Glycolipids
Aquaporins facilitate the transport of:
Ions
Glucose
Amino acids
Water
