Which characteristic distinguishes facilitated diffusion from simple diffusion across a biological membrane?
Movement down a concentration gradient
Specificity for the transported molecule
Passive transport requiring no energy input
Dependence on membrane fluidity
Related Questions
Water channels are possessed by a membrane to facilitate the movement of hydrophilic substances.
These channels are made up of
Proteins
Lipids
Carbohydrates
Nucleic acids
Consider the following statements and choose the correct answer
I. Carrier proteins are needed by both facilitated diffusion and active transport and are sensitive to inhibitors that react with protein side chain
II. Different types of proteins present in the membrane plays a major role in both active as well as passive transport
III. The carrier proteins needed by facilitated and active transport are specific
IV. There is no need of energy to pump molecule against a concentration in active transport
V. Transport rate reaches to saturation point, when all the active proteins are used
I, II, II, IV and V
I, II and III
V, IV and I
I, II, III and V
Active transport
Releases energy
Requires energy
Produces ATP
Produces a toxic substance
An example of facilitated diffusion is the transport of:
Oxygen across the cell membrane
Carbon dioxide out of cells
Glucose into cells
Water through aquaporins
Facilitated diffusion involves?
Downhill transport
Without expenditure of energy
Involvement of proteins
All
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
Aquaporins facilitate the transport of:
Ions
Glucose
Amino acids
Water
In facilitated diffusion, the carrier protein:
Hydrolyzes ATP to move the molecule
Undergoes a conformational change to transport the molecule
Forms a channel that remains permanently open
Transports molecules against their concentration gradient
Which of the following pair is selective and specific mode of transport?
Passive transport and active transport
Passive transport and facilitated diffusion
Facilitated diffusion and active transport
Simple diffusion and facilitated diffusion
Water channels are made up of how many different types of aquaporins?
Eight
Four
Five
Twenty
