Question

If glucose is labeled with C-14 in the indicated position, where will the label be in pyruvate?

a.$\mathbf{Glucose}\mathbf{-}\mathbf{1}\mathbf{-}{}^{\mathbf{14}}\mathbf{C}$

b. $\mathbf{Glucose}\mathbf{-}\mathbf{2}\mathbf{-}{}^{\mathbf{14}}\mathbf{C}$

c. $\mathbf{Glucose}\mathbf{-}\mathbf{3}\mathbf{-}{}^{\mathbf{14}}\mathbf{C}$

d. $\mathbf{Glucose}\mathbf{-}\mathbf{4}\mathbf{-}{}^{\mathbf{14}}\mathbf{C}$

e. $\mathbf{Glucose}\mathbf{-}\mathbf{5}\mathbf{-}{}^{\mathbf{14}}\mathbf{C}$

f.$\mathbf{Glucose}\mathbf{-}\mathbf{6}\mathbf{-}{}^{\mathbf{14}}\mathbf{C}$

Short answer

The answer is,

a.

b.

c.

d.

e.

f.

Step-by-step solution

Pyruvate

The carbons in D- glyceraldehydes- 3- phosphate corresponds to the carbon in pyruvate as shown below.

D- glyceraldehydes-3- phosphate pyruvate

Subpart (a)

The label in the pyruvate is as shown below.

Labelled Structure

Subpart (b)

The label in the pyruvate is as shown below.

Labelled Structure

Subpart (c)

The label in the pyruvate is as shown below.

Labelled Structure

Subpart (d)

The label in the pyruvate is as shown below.

Labelled Structure

Subpart (e)

The label in the pyruvate is as shown below.

Labelled Structure

Subpart (f)

The label in the pyruvate is as shown below.

Labelled Structure