Primary Active Membrane Transport - Video Tutorials & Practice Problems
On a tight schedule?
Get a 10 bullets summary of the topic
1
concept
Primary Active Membrane Transport
Video duration:
3m
Play a video:
Video transcript
In this video we're going to begin talking about primary active membrane transport. Now recall from our previous lesson videos that active transport is an active or an energy driven process that transports molecules against their concentration gradient from areas of low concentration to areas of high concentration. And really, there are 2 main types of active membrane transport that you guys should know. The very first type is primary active transport, and the second type is secondary active transport. Now, for now and in our next couple of videos, we're going to focus, mainly on primary active transport. But later in our course, we'll talk more about secondary active transport. Now primary active transport is usually what people refer to when they just say the words active transport. And so primary active transport is gonna be directly driven by an energy source, such as the ATP hydrolysis. Now secondary active transport, again, which we'll talk more about later in our course, is not directly driven by ATP hydrolysis. Instead, secondary active transport is directly driven by an electrochemical ion gradient that is built up over time. And again, we'll talk more about secondary active transport later in our course. But down below in our image, what you'll notice is, we have our map of the lesson on membrane transport. And so we've already talked about passive transport here, and we're now starting to focus more on active transport. And, we're specifically going to talk more about primary active transport moving forward, when we talk about the 5 types of ATPases and then specific types of, these ATPases. And then again later, we will focus more on secondary active transport. Now, here in these two boxes, what you'll notice is the left one, because you can see ATP hydrolysis is directly involved in this process of pumping a molecule from low right hand side, notice that there is no ATP molecule anywhere to be found over here, and so, we do have, the transport of a molecule, the green one over here, from low concentration to high concentration. And so this green arrow represents a type of active transport. But because there is no ATP involved, directly involved, this is going to be secondary active transport. And again, we'll talk a lot more about this one later in our course, but it's gonna be driven by the flow of another chemical down its electrochemical gradient. But, for now, this here concludes our introduction to primary active transport. And again, moving forward in our lesson, we're going to talk about the 5 types of ATPases, which are all driving primary active transport. And so I'll see you guys in our next video.
2
concept
Primary Active Membrane Transport
Video duration:
5m
Play a video:
Video transcript
In this video we're going to talk about the types of primary active transport ATPases. Now ATPase ends in the letters a s e which we know indicates that it is an enzyme, and so ATPases are enzymes that utilize or hydrolyze ATP. And so primary active transport ATPases are ATPases that perform primary active transport, and transport molecules across a membrane against their concentration gradient. And so again, these primary active transport ATPases, they're defined as transporters that hydrolyze, to no surprise, ATP, in order to pump molecules, again, against their concentration gradients from areas of low concentration to areas of high concentration across the membrane. Now really there are 5 main types of primary active transport ATP ases that you guys should know. And notice down below in our table, we were going to discuss each of those 5 different types. Now notice in the first column what we have is the ATPase type and in the second column what we have is the function of that ATPase. And notice that in each of the functions, we have a letter that is bolded to help remind you guys of what exactly the, type of ATPase it is. And so for example, if we take a look at this first type of ATPase here, what you'll notice is that its function is to transport cations such as sodium and potassium cations, and, specifically what defines them is that they are reversibly phosphorylated by ATP. And so, because these guys are reversibly phosphorylated, the phosphorylated part reminds you that this is the p type ATPase. And so over here what we have is an image of a transporter of an ATPase, and one thing to note is that it is specifically phosphorylated itself, and it creates a phosphorylated intermediate. And so really this is what defines the p type ATPase. Now moving forward in our course, we're going to talk about 2 specific types of p type ATPases, and those are the sodium potassium pump or the sodium potassium ATPase and the circa pump or the calcium ion pump. And again, we'll talk about those 2 types of a t of p type ATPases later in our course. But moving on here to the second type of ATPase, what we have is their function is to transport hydrogen ions to acidify intracellular regions of vesicles. And really, the v here in vesicles reminds us that this is going to be the v type ATPase. And so, lysosomes are, recall, vesicles that are found in animal cells that are responsible for recycling materials within the cell. And so v type ATPases play a big role in forming lysosomes and the acidic environment within lysosomes. Now moving on to our third type of ATPase, the their function is to transport free hydrogen ions across mitochondrial membranes producing ATP. And so these guys actually function in the reverse way where whereas instead of hydrolyzing ATP, they actually function to produce ATP, and so they're also known as ATP synthases. And again, these guys are important in mitochondrial membranes and so we have the mitochondria over here saying, you're free, just to remind you that these are the f type ATPases. And so, we'll talk more about f type ATPases much later in our course when we talk about mitochondrial function. But for now, let's move on to our 4th type of ATPase which is, the a type ATPase, and that's because its function is to transport anions across archaeal cell membranes. And so over here what we have is an image of an archaeal, cell. And, again, again, you can see these anions that are on the outside, reminding us that this transports anions across archaeal cell membranes. Now last but not least, our 5th type of ATPase is actually the a b c transporters, And that's because this ATPase, its function is to transport many types of solutes including drugs and toxins, and it does that by utilizing an ATP binding cassette, which we'll talk more about exactly what this is later in our course as well. But for now what you can see is over here what we have is some kind of drug or toxin, and you can see that it's being canceled out because these a b c transporters will pump these drugs so that, they do not have an effect within cells. And again, we'll talk more about this idea later in our course. And then of course we have this AB ATP mixtape over here to remind you of the ATP binding cassette. And so, this here concludes our introduction to the types of primary active transport ATP aces, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you guys in our next video.
3
Problem
Problem
What initial effect would the loss of ATP production have on a cell's ability to transport substances?
A
The cell would only be able to transport substances using active transport.
B
The cell would be able to transport substances using active and passive transport.
C
The cell would only be able to transport substances using passive diffusion.
D
The transport of all substances across the membrane would stop.
4
Problem
Problem
What is the main difference between active transport and facilitated transport?
A
Facilitated transport uses proteins, but active transport does not.
B
Active transport uses ATP to power transport, but facilitated transport does not.
C
Active transport occurs across the plasma membrane, but facilitated transport does not.
D
Active transport moves a substance from higher concentration low concentration, while facilitated transport moves a substance from low concentration to high concentration.
E
All of the above are differences between active and facilitated transport.
5
Problem
Problem
P-type ATPases ________.
A
Transport phosphate against its concentration gradient.
B
Undergo reversible phosphorylation by ATP hydrolysis.
C
Transport anions only.
D
Transports phosphate with its concentration gradient.
E
Phosphorylates cations so they can be transported into the cell.