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
Related Questions
Facilitated diffusion
Needs a carrier protein
Is an active process
Occurs against the concentration gradient
Needs ATP
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
What are the aquaporins in facilitated diffusion process?
Membrane proteins
Carrier proteins
Channel proteins
Carrier lipids
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
Active transport differs from facilitated transport as the former
Requires special membrane protein
Is highly selective
Shows response to protein inhibitors
Is ATP dependent
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
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
If two molecules A & B move in the same direction. This movement can be called
Antiport
Symport
Uniport
Guttation
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
If two molecules A & B move in the same direction. This movement can be called
Antiport
Symport
Uniport
Guttation
