Amino Acid Metabolism - the Methionine (SAM) Cycle

The video tutorial explains the SAM cycle, highlighting the formation of S-adenosylmethionine (SAM) from methionine, its role as a methyl donor, and the conversion to S-adenosyl-homocysteine. It discusses the regeneration of methionine, emphasizing the importance of vitamin B12 and folate. The tutorial also covers the consequences of deficiencies in these vitamins, such as elevated homocysteine levels and potential cardiovascular risks.

What is S-adenosylmethionine (SAM) and why is it important in biological reactions?

Describe the process by which methionine is converted to S-adenosylmethionine.

What role do cofactors like N5-methyltetrahydrofolate and cobalamin play in the methionine synthase reaction?

What is the overall impact of methionine synthesis on the SAM cycle?

Explain the consequences of a deficiency in cobalamin (vitamin B12) on methionine and homocysteine levels.

What is the significance of elevated homocysteine levels in relation to cardiovascular diseases?

How does the resupplementation of cobalamin or folate affect the activity of methionine synthase?