Q. 18.76 - An Introduction to General, Organic, and Biological Chemistry

Question

Identify each of the following as a six-carbon or a three-carbon compound and arrange them in the order in which they occur in glycolysis:

a. $3-phosphoglycerate$

b. $pyruvate$

c. $glu\cos e-6-phosphate$

d. $glu\cos e$

e. $fructose-1,6-bisphosphate$

Step-by-Step Solution

Answer

a. $3-phosphoglycerate$ is a $3-\mathrm{carbon}$ compound.

b. $pyruvate$ is a $3-\mathrm{carbon}$ compound.

c. $\mathrm{glucose}-6-\mathrm{phosphate}$ is a $6-\mathrm{carbon}$ compound.

d. $glu\cos e$ is a $6-\mathrm{carbon}$ compound.

e. $fructose-1,6-bisphosphate$ is a $6-\mathrm{carbon}$ compound.

part (a) Step 1: Given Information

We need to identify $3-phosphoglycerate$ is six-carbon or a three-carbon compound and arrange it in the order in which it occurs in glycolysis.

Part (a) Step 2: Explanation

$3-phosphoglycerate$ is a $3-carbon$ compound, is an intermediate substrate in glycolysis. This reaction is at the $7th$ step of glycolysis. $3-phosphoglycerate$ is obtained through the transfer of phosphate from $1,3-bisphosphoglycerate$ and this reaction is catalyzed by $\mathrm{phosphoglycerate}$ kinase.

part (b) Step 1: Given Information

We need to identify $pyruvate$ is six-carbon or a three-carbon compound and arrange it in the order in which it occurs in glycolysis.

Part (b) Step 2: Explanation

$\mathrm{Pyruvate}$ is a three carbon compound that come from product of glycolysis. It is the final product that can be obtained from the oxidation of glucose from glycolysis. $Pyruvate$ is obtained from a substrate of phosphorylation of phosphoenolpyruvate. This is the process that is catalyzed by the enzyme $\mathrm{pyruvate} \mathrm{kinase}$. As $\mathrm{pyruvate}$ is the end product of glycolysis so it can found at the $10th$ step of the metabolic pathway.

part (c) Step 1: Given Information

We need to identify $glu\cos e-6-phosphate$ is six-carbon or a three-carbon compound and arrange it in the order in which it occurs in glycolysis.

Part (c) Step 2: Explanation

$\mathrm{Glucose}-6-\mathrm{phosphate}$ is a $6-\mathrm{carbon}$ compound which is an intermediate of glycolysis. It results from the phosphorylation of glucose substrate upon its entry into the glycolytic pathway. This reaction is catalyzed by $\mathrm{hexokinase}$. $\mathrm{Glucose}-6-\mathrm{phosphate}$ is found at the second step of glycolysis.

part (d) Step 1: Given Information

We need to identify $glu\cos e$ is six-carbon or a three-carbon compound and arrange it in the order in which it occurs in glycolysis.

Part (d) Step 2: Explanation

Glucose is a $6-\mathrm{carbon}$ compound which is the main substrate of glycolysis. It is the starting material of a metabolic pathway to produce $\mathrm{pyruvate}$ and ATPs. It is found in the first step of glycolysis.

part (e) Step 1: Given Information

We need to identify $fructose-1,6-bisphosphate$ is six-carbon or a three-carbon compound and arrange it in the order in which it occurs in glycolysis.

Part (e) Step 2: Explanation

$\mathrm{Fructose}-1,6-\mathrm{bisphosphte}$ is a $6-carbon$ compound, i.e. an intermediate of glycolysis. It is derived from $\mathrm{fructose}-6-\mathrm{phosphate}$ upon its phosphorylation. The phosphorylation of $\mathrm{fructose}-6-\mathrm{phosphate}$ to $\mathrm{fructose}-1,6-\mathrm{bisphosphate}$ that is found in the $3rd$ step of glycolysis.