Question

Choline, recently reclassified as essential, A. cannot be synthesized de noun. B. affects DNA methylation so is critical during fetal development. C. deficiency has never been demonstrated in humans because it is abundant in the diet. D. is necessary to maintain the coenzyme A supply in mitochondria. E. supplementation raises serum homocysteine.

Short answer

A. Choline cannot be synthesized de novo. B. Choline affects DNA methylation, so it is critical during fetal development. C. Choline deficiency has never been demonstrated in humans because it is abundant in the diet. D. Choline is necessary to maintain the coenzyme A supply in mitochondria. E. Choline supplementation raises serum homocysteine. Answer: B. Choline affects DNA methylation, so it is critical during fetal development.

Step-by-step solution

Understanding Choline

Choline is an essential nutrient that plays a crucial role in many biological processes, including cell structure, signaling, and neurotransmission. It is required for brain development, the synthesis of acetylcholine, and the maintenance of the structural integrity of cell membranes. Now, let's evaluate each statement.

Analyzing statement A

"Choline cannot be synthesized de novo." Although Choline can be synthesized by the liver, it is not enough to meet the body's requirements, which is why it is considered an essential nutrient that must be obtained from the diet. So, statement A is incorrect.

Analyzing statement B

"Choline affects DNA methylation, so it is critical during fetal development." Choline is involved in the process of DNA methylation, a fundamental mechanism for regulating gene expression. Adequate Choline intake during pregnancy is crucial for proper fetal development, as it affects neurological development and cognitive function in the offspring. Statement B is correct.

Analyzing statement C

"Choline deficiency has never been demonstrated in humans because it is abundant in the diet." Choline deficiency has been shown in humans, particularly in pregnant women, vegetarians, and those with certain genetic mutations. Inadequate Choline intake can lead to fatty liver, muscle damage, and even neurological disorders. So, statement C is incorrect.

Analyzing statement D

"Choline is necessary to maintain the coenzyme A supply in mitochondria." Choline is not directly involved in maintaining the coenzyme A supply in mitochondria. Coenzyme A is synthesized from pantothenic acid (vitamin B5), not Choline. So, statement D is incorrect.

Analyzing statement E

"Choline supplementation raises serum homocysteine." Choline supplementation can help lower homocysteine levels in the body, as it aids in the conversion of homocysteine to methionine. Elevated homocysteine levels are associated with an increased risk of heart disease and other health problems. So, statement E is incorrect as well. Based on the analysis of each statement, the correct answer is: B. Choline affects DNA methylation, so it is critical during fetal development.