Question

What metabolic substrate(s) are produced from the carbon atoms of each of the following amino acids?

a. leucine

b. asparagine

c. cysteine

d. arginine

Short answer

Metabolic substrate(s) produced from the carbon atoms of each of the following amino acids is (are):-

a. leucine- Acetyl-CoA and acetoacetate.

b. asparagine- Oxaloacetate.

c. cysteine- Pyruvate

d. arginine- $\alpha$-ketoglutarate

Step-by-step solution

Part(a) Step 1: Given information   

We have been given a amino acid leucine.

We need to find out what metabolic substrate(s) are produced from the carbon atoms of given amino acid.

Part(a) Step 2: Explanation  

The seven products of amino acid carbon skeleton catabolism are:-

1. Oxaloacetate
2. $\alpha$-ketoglutarate
3. Pyruvate
4. Fumarate
5. Succinyl coenzyme A (CoA)
6. Acetyl CoA
7. Acetoacetate

In the energy metabolism, they have a different fate.

Leucine is exclusively ketogenic and ultimately converted into acetyl-CoA and acetoacetate.

Part(b) Step 1: Given information   

We have been given a amino acid asparagine.

We need to find out what metabolic substrate(s) are produced from the carbon atoms of given amino acid.

Part(b) Step 2: Explanation  

The seven products of amino acid carbon skeleton catabolism are:-

1. Oxaloacetate
2. $\alpha$-ketoglutarate
3. Pyruvate
4. Fumarate
5. Succinyl coenzyme A (CoA)
6. Acetyl CoA
7. Acetoacetate

Asparaginase is an enzyme that converts asparagine to ammonia and aspartate. Transamination removes the amino group from aspartate, resulting in oxaloacetate.

Part(c) Step 1: Given information 

We have been given a amino acid cysteine.

We need to find out what metabolic substrate(s) are produced from the carbon atoms of given amino acid.

Part(c) Step 2: Explanation  

The seven products of amino acid carbon skeleton catabolism are:-

1. Oxaloacetate
2. $\alpha$-ketoglutarate
3. Pyruvate
4. Fumarate
5. Succinyl coenzyme A (CoA)
6. Acetyl CoA
7. Acetoacetate

Pyruvate is formed when cysteine is metabolized.

Part(d) Step 1: Given information   

We have been given a amino acid arginine.

We need to find out what metabolic substrate(s) are produced from the carbon atoms of given amino acid.

Part(d) Step 2: Explanation 

The seven products of amino acid carbon skeleton catabolism are:-

1. Oxaloacetate
2. $\alpha$-ketoglutarate
3. Pyruvate
4. Fumarate
5. Succinyl coenzyme A (CoA)
6. Acetyl CoA
7. Acetoacetate

Arginase breaks down arginine to make ornithine. After that, ornithine is transformed to $\alpha$-ketoglutarate.