WEBVTT
00:00:59.039 --> 00:01:03.839
How does a beta cell know glucose is rising?
00:01:06.400 --> 00:01:07.599
Imagine this.
00:01:07.840 --> 00:01:10.079
Breakfast is being digested.
00:01:10.640 --> 00:01:17.679
And I'm sure by now you're probably thinking, man, she sure loves breakfast because I always like using it as an analogy.
00:01:18.079 --> 00:01:20.159
And you wouldn't be entirely wrong.
00:01:20.400 --> 00:01:22.959
But yes, let's go back to our breakfast.
00:01:23.120 --> 00:01:30.560
So breakfast is being digested, glucose availability is rising, and our beta cell is watching.
00:01:30.879 --> 00:01:33.280
But remember our question, how?
00:01:34.400 --> 00:01:38.319
Glucose reaches the beta cell and enters it.
00:01:38.799 --> 00:01:44.239
And once inside, the cell begins metabolizing that glucose.
00:01:45.199 --> 00:01:52.640
We're going to spend a lot of time later learning exactly what happens to glucose inside cells.
00:01:52.879 --> 00:01:58.479
Glycolysis, pyruvate, the citric acid cycle, mitochondria.
00:01:59.120 --> 00:02:02.399
For today, we only need part of the story.
00:02:02.719 --> 00:02:11.039
As glucose metabolism increases in the beta cell, the cell's energetic state changes.
00:02:11.599 --> 00:02:17.199
One important change is the relationship between ATP and ADP.
00:02:18.319 --> 00:02:29.519
You've met ATP before as an energy carrying molecule that we discussed at length while we were doing the mitochondria decoded series.
00:02:29.759 --> 00:02:41.840
We talked about how ATP is the energy currency that our body uses, kind of like how you need money for almost any transaction if you want to get something in return.
00:02:42.000 --> 00:02:52.399
The same principle applies to ATP for every single action that occurs in the body, from your heartbeat to thinking, all of it requires ATP.
00:02:52.639 --> 00:02:55.920
And that same molecule is what we're talking about now.
00:02:57.039 --> 00:03:01.519
So as I mentioned, ATP is an energy carrying molecule.
00:03:01.840 --> 00:03:07.359
But when it comes to metabolism, you'll find that it becomes a little even more interesting.
00:03:07.680 --> 00:03:14.960
In this beta cell, changing ATP simply isn't useful because the cell needs energy.
00:03:15.280 --> 00:03:17.599
The change becomes information.
00:03:18.079 --> 00:03:23.280
It's part of the signal that says glucose availability has increased.
00:03:23.599 --> 00:03:24.719
Think about that.
00:03:24.960 --> 00:03:28.079
The cell didn't need a human design glucose sensor.
00:03:28.240 --> 00:03:31.280
It used metabolism itself as a sensor.
00:03:31.520 --> 00:03:39.919
Glucose came in, the cell processed it, ATP changed, and now that change can affect other machinery.
00:03:40.479 --> 00:03:45.120
This idea is going to follow us throughout this entire series.
00:03:45.599 --> 00:03:52.560
Cells constantly gather information about their internal energetic and nutrient state.
00:03:52.879 --> 00:04:02.000
Later, we'll meet molecules such as AMPK again that help cells respond when energy availability changes.
00:04:02.240 --> 00:04:04.960
We'll also meet MTOR once more.
00:04:05.280 --> 00:04:10.719
MTOR participates in sensing conditions related to nutrients and growth.
00:04:11.039 --> 00:04:14.159
Cancer cells manipulate metabolic sensing.
00:04:14.400 --> 00:04:18.960
Immune cells change metabolism when they become activated.
00:04:19.279 --> 00:04:23.840
But right now, we're inside one beta cell after breakfast.
00:04:24.079 --> 00:04:26.399
Glucose metabolism has increased.
00:04:26.720 --> 00:04:30.000
ATP has risen relative to ADP.
00:04:30.399 --> 00:04:34.720
We'll talk a little bit more about the differences in future episodes.
00:04:35.039 --> 00:04:41.120
Insulin is waiting inside secretory granules, and yet nothing has been released.
00:04:41.360 --> 00:04:43.840
We still need to connect the two events.
00:04:44.159 --> 00:04:54.319
How does a change in cellular energy make a better cell, or excuse me, a beta cell dump insulin into the bloodstream?
00:04:54.639 --> 00:04:58.639
For that, we need a tiny potassium channel.
00:04:58.800 --> 00:05:01.360
And things are about to get electrical.
00:05:01.600 --> 00:05:03.360
See you in the next episode.
00:00:59.039 --> 00:01:03.839
How does a beta cell know glucose is rising?
00:01:06.400 --> 00:01:07.599
Imagine this.
00:01:07.840 --> 00:01:10.079
Breakfast is being digested.
00:01:10.640 --> 00:01:17.679
And I'm sure by now you're probably thinking, man, she sure loves breakfast because I always like using it as an analogy.
00:01:18.079 --> 00:01:20.159
And you wouldn't be entirely wrong.
00:01:20.400 --> 00:01:22.959
But yes, let's go back to our breakfast.
00:01:23.120 --> 00:01:30.560
So breakfast is being digested, glucose availability is rising, and our beta cell is watching.
00:01:30.879 --> 00:01:33.280
But remember our question, how?
00:01:34.400 --> 00:01:38.319
Glucose reaches the beta cell and enters it.
00:01:38.799 --> 00:01:44.239
And once inside, the cell begins metabolizing that glucose.
00:01:45.199 --> 00:01:52.640
We're going to spend a lot of time later learning exactly what happens to glucose inside cells.
00:01:52.879 --> 00:01:58.479
Glycolysis, pyruvate, the citric acid cycle, mitochondria.
00:01:59.120 --> 00:02:02.399
For today, we only need part of the story.
00:02:02.719 --> 00:02:11.039
As glucose metabolism increases in the beta cell, the cell's energetic state changes.
00:02:11.599 --> 00:02:17.199
One important change is the relationship between ATP and ADP.
00:02:18.319 --> 00:02:29.519
You've met ATP before as an energy carrying molecule that we discussed at length while we were doing the mitochondria decoded series.
00:02:29.759 --> 00:02:41.840
We talked about how ATP is the energy currency that our body uses, kind of like how you need money for almost any transaction if you want to get something in return.
00:02:42.000 --> 00:02:52.399
The same principle applies to ATP for every single action that occurs in the body, from your heartbeat to thinking, all of it requires ATP.
00:02:52.639 --> 00:02:55.920
And that same molecule is what we're talking about now.
00:02:57.039 --> 00:03:01.519
So as I mentioned, ATP is an energy carrying molecule.
00:03:01.840 --> 00:03:07.359
But when it comes to metabolism, you'll find that it becomes a little even more interesting.
00:03:07.680 --> 00:03:14.960
In this beta cell, changing ATP simply isn't useful because the cell needs energy.
00:03:15.280 --> 00:03:17.599
The change becomes information.
00:03:18.079 --> 00:03:23.280
It's part of the signal that says glucose availability has increased.
00:03:23.599 --> 00:03:24.719
Think about that.
00:03:24.960 --> 00:03:28.079
The cell didn't need a human design glucose sensor.
00:03:28.240 --> 00:03:31.280
It used metabolism itself as a sensor.
00:03:31.520 --> 00:03:39.919
Glucose came in, the cell processed it, ATP changed, and now that change can affect other machinery.
00:03:40.479 --> 00:03:45.120
This idea is going to follow us throughout this entire series.
00:03:45.599 --> 00:03:52.560
Cells constantly gather information about their internal energetic and nutrient state.
00:03:52.879 --> 00:04:02.000
Later, we'll meet molecules such as AMPK again that help cells respond when energy availability changes.
00:04:02.240 --> 00:04:04.960
We'll also meet MTOR once more.
00:04:05.280 --> 00:04:10.719
MTOR participates in sensing conditions related to nutrients and growth.
00:04:11.039 --> 00:04:14.159
Cancer cells manipulate metabolic sensing.
00:04:14.400 --> 00:04:18.960
Immune cells change metabolism when they become activated.
00:04:19.279 --> 00:04:23.840
But right now, we're inside one beta cell after breakfast.
00:04:24.079 --> 00:04:26.399
Glucose metabolism has increased.
00:04:26.720 --> 00:04:30.000
ATP has risen relative to ADP.
00:04:30.399 --> 00:04:34.720
We'll talk a little bit more about the differences in future episodes.
00:04:35.039 --> 00:04:41.120
Insulin is waiting inside secretory granules, and yet nothing has been released.
00:04:41.360 --> 00:04:43.840
We still need to connect the two events.
00:04:44.159 --> 00:04:54.319
How does a change in cellular energy make a better cell, or excuse me, a beta cell dump insulin into the bloodstream?
00:04:54.639 --> 00:04:58.639
For that, we need a tiny potassium channel.
00:04:58.800 --> 00:05:01.360
And things are about to get electrical.
00:05:01.600 --> 00:05:03.360
See you in the next episode.
