Although catabolism of a glucose molecule eventually produces a lot of energy, the first step us

Although catabolism of a glucose molecule eventually...

Key Concepts

Activation of Molecules

Activation of molecules involves modifying a substrate through a chemical change, such as phosphorylation, to make it more chemically reactive. This modification is essential for enabling the substrate to engage in subsequent metabolic reactions that ultimately lead to a large net production of energy.

Energy Coupling

Energy coupling is the process by which the energy released from an exergonic reaction, such as ATP hydrolysis, is harnessed to drive an endergonic reaction. In metabolic pathways, this coupling ensures that steps requiring an input of energy, which are necessary for activating substrates, can occur efficiently despite their inherent energetic cost.

Energy Investment Phase

This concept refers to the initial stage in a metabolic pathway where energy, typically in the form of ATP, is consumed. This deliberate expenditure of energy transforms stable substrates into more reactive intermediates, setting the stage for subsequent reactions in which a greater net yield of energy is produced.

Transcript

00:02 Hello everyone.

00:05 Or question of analysis in this segment reads, the first step of glucose metabolism uses up energy, even though catabolism or glucose metabolism eventually produces a lot of energy.

00:22 What is the reason for this? or explain the reason this step is necessary.

00:29 Firstly, we recognize that our question is asking about glucose metabolism or for the breaking up of glucose to form other molecules.

00:42 An important step is to first analyze what it is the glucose molecule looks like.

00:50 And we will do a bit of drawing here.

00:56 Glucose is a six carbon molecule.

01:02 So a six carbon molecule.

01:05 And it looks something like this.

01:07 So we're drawing in green.

01:15 All right.

01:19 And each vertex that we have represents a carbon.

01:28 This is not a vertex, so that is an oxygen atom.

01:37 This is a vertex, so that's a carbon.

01:40 So is this one.

01:49 And so is this one.

01:52 Currently, we only have a 5 .1, 2, 3, 4, 5.

01:55 So our next carbon is attached to this carbon.

02:02 All right, and it's important to note that this carbon has 1h here, or h signifies a hydrogen atom, and it also has a hydroxyl group, or an oh, an alcohol group here.

02:30 Remember that, or hydroxols normally have two lone pairs of electrons.

02:39 And the reason those are significant is, as we will see later.

02:46 We will see later the reason those alone pairs are significant.

02:52 So each of these carbon atoms has one hydrogen and one hydroxyl.

03:04 Or h going up on this one, oh going down, on this one, or h is going up, oh down, or h is going up, oh down, here, the reverse.

03:26 H going down.

03:31 Here, h going up, and oh going down.

03:40 All right.

03:40 So if we count, we now see that we have 1, 2, 3, 4, 5, 6.

03:51 6 carbon atoms total.

03:54 No, in the first stages, in the first stages of glucose.

04:01 Metabolism, what happens? we see our glucose molecule.

04:10 This one is specifically the alpha de -glucose, the alpha -de -glucose molecule, which means that there are other orientations to the glucose molecule.

04:33 We see in our first stages of glucose metabolism that energy is being used up according to our statement.

04:44 And what that entails is that we have, we have adenicentrophosphate.

04:52 That's atp, adenisantrophosphate, which provides our energy.

04:58 Otherwise, it provides the electrons that have the energy.

05:03 The adenicentrophosphate is being broken down to adenicin diphosphate.

05:09 All right, so it yields adenicin diphosphate.

05:13 And what this forms, what happens is that we see it's being reduced from a tri -phosphate to a diphosphate, going down in number.

05:32 Actually, what's happening is that it's being oxidized.

05:36 So being reduced in the term of, in terms of the number of phosphate groups on there, but what is actually happening is that this molecule is being oxidized because it is losing the electrons.

05:48 So it is being oxidized.

05:54 So what happens is that now our glucose molecule, let's go back to our green given that we started there with a green.

06:06 Our glucose molecule is taking on some new elements.

06:12 Or rather, it's taking on just one new element.

06:16 So where does that go? now, it is keeping the general orientation.

06:24 Exactly what we have here is what, exactly what we started with, the first orientation is what we will keep.

06:35 All right, let's draw that down, draw that down.

06:42 It's an h, an oh, h, and an oh.

06:49 The reverse here, hydroxyl on top, h, here.

06:58 We have a hydrogen, and then the oh.

07:03 Now, this, our fifth carbon, which has our two hydrogen atoms, and initially had a hydroxyl group here, had a replacing of the hydrogen atom that was originally on this oxygen, and it was replaced with the hydrogen atom.

07:36 Phosphate group...

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