C1.1.16. Regulation of metabolic pathways by feedback inhibition

Some bacteria can synthesize the amino acid isoleucine from threonine, a process involving five enzymes (E₁ to E₅) and four intermediary products (P, Q, R and S). The production of isoleucine is controlled by end-product inhibition.

Which statement describes this end-product inhibition?

A. If isoleucine accumulates, it inhibits the production of P.

B. End-product inhibition causes a build-up of intermediary products.

C. Isoleucine inhibits E₅, so no more isoleucine is produced.

D. Isoleucine affects the structure of threonine.

Some bacteria can synthesize the amino acid isoleucine from threonine, a process involving five enzymes (E₁ to E₅) and four intermediary products (P, Q, R and S). The production of isoleucine is controlled by end-product inhibition.

Which statement describes this end-product inhibition?

A. If isoleucine accumulates, it inhibits the production of P.

B. End-product inhibition causes a build-up of intermediary products.

C. Isoleucine inhibits E₅, so no more isoleucine is produced.

D. Isoleucine affects the structure of threonine.

Some bacteria can synthesize the amino acid isoleucine from threonine, a process involving five enzymes (E₁ to E₅) and four intermediary products (P, Q, R and S). The production of isoleucine is controlled by end-product inhibition.

Which statement describes this end-product inhibition?

A. If isoleucine accumulates, it inhibits the production of P.

B. End-product inhibition causes a build-up of intermediary products.

C. Isoleucine inhibits E₅, so no more isoleucine is produced.

D. Isoleucine affects the structure of threonine.

Some bacteria can synthesize the amino acid isoleucine from threonine, a process involving five enzymes (E₁ to E₅) and four intermediary products (P, Q, R and S). The production of isoleucine is controlled by end-product inhibition.

Which statement describes this end-product inhibition?

A. If isoleucine accumulates, it inhibits the production of P.

B. End-product inhibition causes a build-up of intermediary products.

C. Isoleucine inhibits E₅, so no more isoleucine is produced.

D. Isoleucine affects the structure of threonine.

Distinguish between competitive and non-competitive enzyme inhibition.

Distinguish between competitive and non-competitive enzyme inhibition.

Distinguish between competitive and non-competitive enzyme inhibition.

Through a series of enzymatic reactions, the amino acid threonine is converted to isoleucine. The graph shows the rate of reaction of threonine deaminase according to the concentration of its substrate threonine, with and without the presence of isoleucine.

^{[Source: Calhoun, D.H., Rimernian, R.A. and Hatfield, G.W., 1973.
Threonine Deaminase from Escherichia coli.
I. Purification and Properties. The Journal Of Biological Chemistry,
248(10), pp. 3511–3516. Open Access.]}

What can be seen from these results?

A.  Threonine deaminase only works in the presence of isoleucine.

B.  Isoleucine inhibits threonine deaminase at low concentrations of threonine.

C.  Production of isoleucine is inhibited at high concentration of threonine.

D.  End-product inhibition controls the production of threonine deaminase.

Through a series of enzymatic reactions, the amino acid threonine is converted to isoleucine. The graph shows the rate of reaction of threonine deaminase according to the concentration of its substrate threonine, with and without the presence of isoleucine.

^{[Source: Calhoun, D.H., Rimernian, R.A. and Hatfield, G.W., 1973.
Threonine Deaminase from Escherichia coli.
I. Purification and Properties. The Journal Of Biological Chemistry,
248(10), pp. 3511–3516. Open Access.]}

What can be seen from these results?

A.  Threonine deaminase only works in the presence of isoleucine.

B.  Isoleucine inhibits threonine deaminase at low concentrations of threonine.

C.  Production of isoleucine is inhibited at high concentration of threonine.

D.  End-product inhibition controls the production of threonine deaminase.

Through a series of enzymatic reactions, the amino acid threonine is converted to isoleucine. The graph shows the rate of reaction of threonine deaminase according to the concentration of its substrate threonine, with and without the presence of isoleucine.

^{[Source: Calhoun, D.H., Rimernian, R.A. and Hatfield, G.W., 1973.
Threonine Deaminase from Escherichia coli.
I. Purification and Properties. The Journal Of Biological Chemistry,
248(10), pp. 3511–3516. Open Access.]}

What can be seen from these results?

A.  Threonine deaminase only works in the presence of isoleucine.

B.  Isoleucine inhibits threonine deaminase at low concentrations of threonine.

C.  Production of isoleucine is inhibited at high concentration of threonine.

D.  End-product inhibition controls the production of threonine deaminase.

Through a series of enzymatic reactions, the amino acid threonine is converted to isoleucine. The graph shows the rate of reaction of threonine deaminase according to the concentration of its substrate threonine, with and without the presence of isoleucine.

^{[Source: Calhoun, D.H., Rimernian, R.A. and Hatfield, G.W., 1973.
Threonine Deaminase from Escherichia coli.
I. Purification and Properties. The Journal Of Biological Chemistry,
248(10), pp. 3511–3516. Open Access.]}

What can be seen from these results?

A.  Threonine deaminase only works in the presence of isoleucine.

B.  Isoleucine inhibits threonine deaminase at low concentrations of threonine.

C.  Production of isoleucine is inhibited at high concentration of threonine.

D.  End-product inhibition controls the production of threonine deaminase.

Explain the regulation of metabolic pathways by end-product inhibition.

Explain the regulation of metabolic pathways by end-product inhibition.

Explain the regulation of metabolic pathways by end-product inhibition.

Explain the regulation of metabolic pathways by end-product inhibition.

Explain the regulation of metabolic pathways by end-product inhibition.

Explain the regulation of metabolic pathways by end-product inhibition.