Question

Thermogenesis is an important function of Brown Adipose Tissue (BAT). Which of the following statements about BAT is FALSE?

I. Unlike other tissues, BAT does not degrade free fatty acids via β-oxidation.

II. BAT has smaller lipid droplets and more mitochondria than White Adipose Tissue.

III. In BAT, UCP1 forms a channel in the inner mitochondrial membrane that dissipates the energy in the H⁺ gradient as heat.

Choose the best answer

I and II

I, II, and III

II and III

II only

I only

Answer 1

(CORRECT ANSWER) (I only)

(EXPLANATION FOR CORRECT ANSWER)   The brown dispose tissue does degrade the free fatty acids via beta-oxidation. These fatty acids then activate the Uncoupling protein 1 which disrupts the cycling of electrons. Fatty acids are the main energy substatre that initiates uncoupling and overcome the cold challenge.

(EXPLANATION FOR INCORRECT ANSWER) (I and II) Point I is incorrect and the same has been explained above. Point II is correct and the explanation is as follows.

Brown adipose tissue is brown in color owing to the presence of large amount of mitochondria. It also contains many small droplets of lipids. The white adipose tissue on the other hand has less mitochondria. Hence white in color and a single lipid droplet.

(EXPLANATION FOR INCORRECT ANSWER) (I, II and III)   Point I is incorrect as explained above. Point II is correct as explained above. Point III is also correct and the explanation is as follows.

Uncoupling protein 1 abbreviated as UCP 1 is a protein found in the inner mitochondrial membrane of the mitochondria found in the brown adipose tissue. It functions to uncoupled the production of ATP from fatty acid oxidation. In the presence of UCP 1 there is no ATP production and the energy derived from oxidation fo fat is dissipated as heat.

(EXPLANATION FOR INCORRECT ANSWER) (II and III) Point II and III are correct as explained above.

(EXPLANATION FOR INCORRECT ANSWER) ( II only) Point II is correct as explained above.