Active Transport - Video Tutorials & Practice Problems

Active Transport

in this video, we're going to begin our lesson on active transport. And really, there are just two main types of active transport that you all should know that both require energy in order to transport molecules. And this is because the molecules are going to be transported against their concentration. Grady INTs from areas of low concentration to areas of high concentration. And that's why it requires energy. Now, the first type of active transport that you all should know is primary active transport. And so primary active transport is going to be directly driven by an energy source such as A T P hydraulics, ISS, for instance. And so primary active transport is directly linked to a T. P. Now, the second type of active transport that you all should know is secondary. Active transport and secondary active transport is not going to be directly driven by a teepee hydraulic sis like primary active transport. Instead, secondary active transport is going to be directly driven by another molecules concentration, Grady int. And so, as we move forward in our course, we'll be able to talk. Mawr details about both primary active transport and secondary active transport. But let's take a look at our image down below, Which notice is showing us a little snippet of the map of the lesson on membrane transport. So here we're showing you active transport and notice. Active transport is going to require energy so energy is required. And once again, there are two main types of active transport. The first is primary active transport, which is going to be driven directly by ATP. And then the second type of active transport is secondary active transport, which is not driven directly by a teepee. Instead, secondary active transport is going to be driven by another molecules, concentration ingredient. And so here, what we're showing you is an image of one molecule being, um, powering the transport of another molecule against its concentration Grady int. And so this here concludes our introduction to active transport. And once again, as we move forward in our course, we're going to talk Mawr details about primary, active transport and secondary active transport. So I'll see you guys in our next videos

Primary Active Transport

So now that we know from our last lesson video that there are two types of active transport primary, active transport and secondary active transport and this video, we're going to focus on primary active transport. And so primary Active transport is an A T P driven process that transports molecules against their concentration ingredients from areas of low concentration to areas of high concentration. And that is why it requires energy in the form of ATP. Now, once again, primary active transport is going to be driven directly by energy derived from a teepee, hydraulics, ISS and really, this is the biggest difference between primary and secondary active transport. Primary active transport is directly linked to a teepee, hydraulics, ISS. But secondary active transport is not as well learn moving forward talking about secondary active transport in another video. Now primary active transport can be used to generate and maintain very, very important concentration. Grady INTs for survival. And so we'll be able to talk about a very, very important primary active transport example in our next lesson video. But for now, let's take a look at the image that we have down below, which is showing US primary active transport. And so notice. Here we have a membrane, uh, here in the middle and notice that primary active transport is going to require the use of a membrane protein. And that membrane protein is going to use ATP directly, as we indicated up above, in order to transport molecules against their concentration. Grady int from an area of low concentration over here on this side of the membrane because they're only three molecules and it's still pumping them towards an area of higher concentration. And so you can see there is a much higher concentration over here. And so because this purple molecule is being pumped against its concentration, Grady in it requires active transport. And because 80 p is used directly, it is a form of primary active transport. And so a teepee here is really providing the energy that is required to pump the molecule across the membrane. And so this year concludes our introduction to primary active transport, and we'll be able to see a very specific example of primary active transport and our next lesson video when we talk about the sodium potassium pump. So I'll see you guys in that video

Active Transport Example 1

all right. So here we have an example Problem that's asking what is the main difference between active transport and facilitated diffusion? And we've got these four potential answer options down below. And so what we need to recall is that facilitated diffusion is not a type of active transport. Facilitated diffusion is a type of passive transport, which means that absolutely no energy is required for facilitated diffusion. And this is because molecules will be transported down their concentration. Grady INTs from an area of high concentration to an area of low concentration. And so when we take a look at Option A here notice, it says, facilitated diffusion uses proteins, but active transport does not, and this is actually a false option, so we can cross it off our list now. This is because both facilitated diffusion and active transport use proteins, and so the facilitated diffusion require is recall is facilitated by a protein and active transport also requires a protein as well. So both facilitated and active transport require proteins, and that is not the main difference between them. Now. Skipping over be really quick going to option C notice, it says Active transport occurs across the plasma membrane, but facilitated diffusion does not. And once again, this is not going to be true. Of course, active transport and facilitated diffusion are both going to allow for molecules to be transported across a plasma membrane. And so they both allow for that. So that is not the main difference between the two and then taking a look at Option D here. It says Active transport and facilitated diffusion. Both use proteins to move substances against their concentration. Grady INTs. Now we already indicated that active transport and facilitated diffusion both use proteins. That part is true, but they don't both move, uh, move substances against their concentration. Grady INTs Onley active transport move substances against their concentration. Grady. It's from areas of low concentration to areas of high concentration but facilitated diffusion, which again is a type of passive transport. It does not pump molecules against their concentration. Grady INTs. It pumps molecules down their concentration. Grady INTs. So that means that option D here is also not going to be true. And this Onley leaves option be here as the correct answer, which says active transport uses a teepee to power transport but facilitated diffusion does not. And so we know from our last lesson video. That's more specifically its primary active transport that uses a teepee directly to power, transport and facilitated diffusion, which is once again a type of passive transport does not require any energy. So it certainly does not use a teepee to power transport. And so option B here is going to be the correct answer for this example problem. And that concludes this example. So I'll see you all in our next video.

The force driving simple diffusion is ________, while the energy source for active transport is ________.

• A. a concentration gradient; ADP
• B. a concentration gradient; ATP hydrolysis
• C. transmembrane pumps; an electrochemical gradient
• D. phosphorylated carrier proteins; ATP

Primary Active Transport: Na+/K+ Pump

in this video, we're going to talk about a classic example of primary active transport in the sodium potassium pump. And so, once again, the sodium potassium pump is a classic example of primary active transport. And as its name implies, the sodium potassium pump is going to pump or move sodium and potassium ions across the plasma membrane. But more specifically, the sodium potassium pump is going to move the sodium and potassium ions in opposite directions across the plasma membrane, which means that the sodium potassium pump is an anti porter, which recall from our previous lesson. Videos just means that some molecules will be pumped across the membrane towards the outside of the cell, whereas other molecules are going to be pumped across the membrane to the inside of the cell in opposite directions. And so that is what makes this an anti porter. Now it turns out that three sodium ions are going to be exported towards the outside of the cell, whereas to potassium ions are going to be imported towards the inside of the cell. And so what can help you remember that it's three sodium ions that are being exported? Is that the sodium here has three characters to it. It has the end. It has the A, and it has the plus. And so this, because it has three characters, can remind you that it's actually three sodium ions that are gonna be exported towards the outside of the cell. And the potassium symbol here has only two characters, so it has the K, and it has the plus, and so that can help remind you that it's too potassium ions that are being imported towards the inside of the cell. Now, what can also help you remember that potassium are going to be imported towards the inside of the cell is too? Just think of a pumpkin, because if you think about a pumpkin, it will tell you that the sodium potassium pump is going to pump K plus into the cell. And so, if you remember pumpkin, you'll remember that. Hey, potassium ions get pumped into the cell or imported into the cell. So let's take a look at our image down below to clear up some of this and notice that right here in the middle, embedded in this plasma membrane that we see right here is the sodium potassium pump right here and notice that the sodium potassium pump is going to take three sodium ions, and those three sodium ions are going to be exported towards the outside of the cell. So notice the outside of the cell is up above on this side of the membrane, whereas the inside of the cells down below. So three sodium ions are going to be pumped or exported towards the outside of the cell. And if that continuously happens over and over and over again, then there's gonna be a low concentration of sodium on the inside of the cell. So remember the brackets here represent the concentration of so we have the concentration of sodium ions on the inside of the cell is gonna be really, really low if it keeps pumping them towards the outside. And, of course, that means that on the outside, over time there's gonna be quite a high concentration of sodium ions on the outside of the cell. And as the sodium ions get pumped, of course, we know that potassium ions are also going to be pumped, but it's actually just to potassium ions that are gonna be imported on DSO. The two potassium ions get imported towards the inside of the cell, and that means that on the outside of the cell, if the potassium ions keep getting pumped in, there's gonna be a low concentration of potassium ions on the outside of the cell and on the inside of the cell. Over time, it's gonna build up, and there's gonna be quite a high concentration of potassium ions on the inside of the cell. And notice that with each pump here, three sodium out and to potassium in, uh, that a teepee hydraulics is required, and the A T P. Here is really what's providing the energy to pump these molecules against their concentration. Grady INTs from areas of low concentration towards areas of high concentration in both scenarios, so from areas of low concentration towards areas of high concentration. Uh, that requires energy, and this is primary active transport because 80 p is directly linked. Now, over here on this right side of the image, we just have another way to help you remember that. Hey, the sodium ions, they get pumped to the outside of the cell and the potassium ions they get pumped to the inside of the cell. And so you can think that the cell here is like a club. It's club interest, cellular, and so you can see that the nucleus here is like the disco D. J at the club. And you could even think that these strobe lights here kind of like the, uh the exoskeleton the sido skeleton of the cell. And so notice that the sodium potassium pump is really gonna act like these bouncers to the club. And so you can see that the sodium ions, when they try to enter the cell, they say, Bra, can we enter into the club and the sodium potassium pump? Because their sodium and they're n a the sodium potassium pump says, Nah, you can't enter, you cannot enter. And so that can help you remember that. Hey, the sodium are not going to enter the cell. They're going to get pumped towards the outside of the cell. However, when the potassium try to get into the club, uh, they say, Well, hey, we're back. Let us in and, uh, the sodium potassium pump because, uh, sodium is made up with K. They just say, Okay, come on in. And so sodium is able to get into the club really easy, and so that can help remind you that Hey, sodium, I'm sorry potassium is gonna be able to get into the cell because the sodium potassium pump says K, come on in. And the sodium over here will not be able to get into the cell, because when they try to enter the sodium potassium pump says Nah. And so this year concludes our introduction to the sodium potassium pump and how it is a classic example of primary active transport, and we'll be able to get some practice applying these concepts as we move forward throughout our course, So I'll see you all in our next video.

A sodium-potassium pump ________.

• A. Transports 3 potassium ions out of a cell and 2 sodium ions into a cell and produces a molecule of ATP.
• B. Transports 3 sodium ions out of a cell and 2 potassium ions into a cell using energy from ATP hydrolysis.
• C. Transports 3 potassium ions out of a cell and 2 sodium ions into a cell using energy from ATP hydrolysis.
• D. Transports 3 sodium ions out of a cell and 2 potassium ions into a cell and generates an ATP in each cycle.

Which of the following defines the type of transport by the sodium-potassium pump?

• A. Active transport through a symporter.
• B. Passive transport through a symporter.
• C. Active transport through an antiporter.
• D. Passive transport through an antiporter.

Secondary Active Transport

So now that we've covered primary active transport in this video, we're going to focus on secondary active transport and so recall from our previous lesson videos that secondary active transport is not directly driven by a teepee hydraulic sis that is primary active transport. Instead, secondary active transport is going to be directly driven by another molecules concentration Grady int, and it's going to be powered by another molecules concentration ingredient instead of being powered by a teepee. Hydrologists like primary active transport ISS. However, that being said secondary active transport. Although it may not be directly driven by a teepee hydraulic sis, it is indirectly driven by primary active transport and a teepee. Hydraulics IHS. And the reason for this is because the concentration ingredient that directly drives secondary active transport is actually built using primary active transport or P A. T, which we've abbreviated here for our lesson. And so, in order to better understand secondary active transport, we're actually going to take a look at a classic example and the sodium glucose secondary active transporter and so down below. We have an image of this sodium glucose transporter and notice that the image has these numbers 123 and four. And these numbers that you see down below and the image correspond with numbers that we have up above here, in the text. And so this is really showing you the four steps that there are for this sodium glucose secondary active transport example. And so in the very first step here, which you'll notice is that sodium ions can be transported against their concentration. Grady int using primary active transport. And so when you take a look at our image down below, noticed that the sodium ion, which we're showing you down below here in step number one, um, is being pumped across the membrane in this direction, and it is being pumped towards the area of higher sodium concentration, whereas down below there's a lower sodium concentration inside the cell. And so because sodium is being pumped against its concentration radiant from low to high concentration, it's going to require energy and noticed that a teepee is directly linked to this process of pumping sodium across the membrane. And because 80 p is directly linked here, it is a form of primary active transport. Just like what we mentioned up above, sodium being transport against this concentration, radiant using primary active transport. But we've already covered primary active transport, so really, this is not anything new to us. And so, essentially in number two, what this is going to generate is a higher concentration of sodium ions generated on the outside of the cell. So the outside of the cell here has a higher concentration of sodium. You can see there are way more sodium ions much, much, much higher concentration than there are inside the cell. So there's a lower sodium ion concentration inside. And this is because again, this primary active transport generates this concentration Grady of sodium. But then what? We need to also realizes in this image and number three, there's another molecule that's also involved here glucose, which we have in green, and so notice down below. We have glucose as well. We have thes green hexagons here and also down below here, and notice that the glucose molecules they actually have a higher concentration on the inside of the cell, which is opposite to that of the sodium. The sodium has a higher concentration on the outside of the cell. The glucose has a higher concentration on the inside of the cell. And so this is really where secondary active transport comes into play because sodium eyes going to be transported down its concentration ingredient from an area of high concentration to an area of low concentration, and that does not require any energy. In fact, it actually can provide and release energy. And so, as the sodium gets transported down its concentration Grady Int, it's actually going to provide the energy. It's going to power the transportation of glucose against its concentration ingredient, from the area of low concentration of glucose towards the area of high concentration of glucose. So once again, to better understand this, let's take a look at this example over here, and what you'll notice is that sodium is going to be transported down its concentration Grady int from an area of high concentration down towards an area of low concentration and that does not require any energy for molecules to move down their concentration. Grady Int. Instead, it's going to release energy and that released energy can be used to power the movement of glucose against its concentration. Grady int from an area of low glucose concentration on the outside of the cell towards an area of much higher glucose concentration on the inside of the cell. And this is really ah type of active transport, since molecule is being transported against its concentration. Grady int. But notice that no a t p. Is directly involved. Notice there's no 80 p in this vicinity at all. And so because it's not driven directly by a TP, it's going to be driven by the concentration Grady int of sodium being transported down its concentration Grady Int. And so that makes this a classic example of secondary active transport. And so, once again, as we mentioned up above with secondary active transport, it's gonna be driven by the concentration Grady in of another molecule instead of a teepee hydraulic sis. So over here with secondary active transport notice that there's no 80 p at all in this vicinity on really, it's just this concentration Grady in of sodium, going down its concentration that powers the secondary active transport here of glucose being transported against its concentration Grady int. And so this year concludes our introduction to secondary active transport, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video

How are primary and secondary active transport related?

• A. They both use ATP to move molecules
• B. Primary active transport establishes a concentration gradient, but secondary active transport doesn't
• C. Secondary active transport uses the concentration gradient established by primary active transport
• D. Primary active transport moves one molecule, but secondary active transport moves two
• E. None of the above