Identify the type of transport (passive diffusion, facilitated...

Question

Identify the type of transport (passive diffusion, facilitated transport, or active transport) that will occur for the following molecules:

(b) nitrogen

Accepted Answer

All right, hello everyone. So this question is asking us to identify the type of transport that will occur for oxygen. That's 02 across a biological membrane option. A says active transport B says facilitated transport, C says passive diffusion and D says osmosis. So first and foremost, what is the difference between active and passive transport? Well, recall that when it comes to molecules and other substances trying to travel from one environment to the other, we tend to understand it as that particular substance. In this case, oxygen following a chemical gradient. So what does that mean? Right. Well, the impulse of a given molecule, A given species is to transfer excuse me, travel from an area of high concentration of that substance towards an area of small or low concentration of that substance. So let me actually write low, right? The idea is that substances like oxygen are compelled to travel from areas of high concentration towards areas of low concentration. And so when the path of a given species is following this gradient, that's called passive transport, this is because no energy is required for that substance to follow its natural gradient. Now, on the other hand, if you have a given substance trying to go against the gradient, in other words, go from an area of low concentration to an area of high concentration that is active transport because it requires energy input to go against that gradient. And so that's what option. A for example is referring to active transport requires energy to be put into the process of moving a substance against its natural gradient. Now both facilitated and passive diffusion are examples of passive transport because no energy is actually required for that substance to move in accordance with its gradient. But the difference is how exactly those substances are moving according to their gradient because we call that a biological membrane is the lipid bilayer. So we have a polar outer part. So polar outer portions of the membrane and a nonpolar inner portion of the membrane because of those fatty acid tails. So some substances especially if they're relatively small and nonpolar can pass through the membrane by themselves. So when you have a situation where you have a small nonpolar molecule passing through the lipid bilayer of the membrane without assistance, according to its chemical gradient, then that is passive diffusion because it doesn't require any assistance to pass the membrane. But the same cannot be said for other species like ions, for example, ions cannot pass through the membrane by themselves. So that's why we have, for example, specific membrane proteins. So here in this instance, if let's say, for example, I have some calcium outside of the cell and it wants to travel into the cell according to its natural gradient. Well, in that instance, calcium, because it's an ion would require the assistance of a membrane protein to travel along its chemical gradient that is facilitated transport. It's still passive because no energy is required for calcium to move in this manner. But it does require assistance of a carrier protein because calcium cannot pass through the membrane on its own. And just to go ahead and address option, D osmosis refers to the passive transport of water specifically. So osmosis describes the movement of water from an area of low salute concentration to high solu concentration across a semi permeable membrane. So osmosis is not going to be our correct answer here because we are talking about oxygen and not water specifically. So speaking of how is oxygen going to move? Well, recall that oxygen is at a higher concentration outside of tissues outside of cells and its concentration is going to be lower inside of the tissues inside of the cells. So here when we're talking about oxygen moving across the biological membrane, it's going to be a form of passive transport because it would move according to its gradient. Now, one more thing to mention if you recall is that oxygen, molecular oxygen is actually nonpolar, it is a nonpolar molecule. So what's happening here? We have a small nonpolar molecule needing to travel from an area of high concentration to an area of low concentration according to its gradient. So what that means is that oxygen can pass through the bilayer directly. It does not need assistance from a carrier protein. So the answer here is going to be c because oxygen would travel across the biological membrane through passive diffusion and there you have it. So with that being said, thank you so very much for watching. And I hope you found this helpful.

Identify the type of transport (passive diffusion, facilitated transport, or active transport) that will occur for the following molecules:
(b) nitrogen

Key Concepts

Passive Diffusion

Facilitated Transport

Active Transport

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