Threonine, Serine, Glycine Catabolism to Pyruvate

The video explores the catabolic pathways of threonine, glycine, and serine, focusing on their degradation to pyruvate and the implications for glucogenic and ketogenic processes. It explains the role of enzymes like threonine dehydrogenase and the glycine cleavage system, highlighting the production of acetyl CoA and NADH. The video also discusses the liver's role in these processes and the importance of gluconeogenesis and ketone body biosynthesis.

What are the two types of products that result from amino acid catabolism?

• Essential and non-essential

• Hydrophilic and hydrophobic

• Anabolic and catabolic

• Glucogenic and ketogenic

Which enzyme initiates the catabolism of threonine?

• Glycine cleavage enzyme

• Citrate synthase

• Serine dehydratase

• Threonine dehydrogenase

What is the primary product of threonine catabolism that is considered ketogenic?

• Glucose

• Pyruvate

• Acetyl CoA

• Oxaloacetate

What is the role of the glycine cleavage system in amino acid catabolism?

• To oxidize NADH

• To convert serine to pyruvate

• To degrade glycine and produce N5 N10 methylene tetrahydrofolate

• To synthesize glucose

Which subunit of the glycine cleavage system is responsible for forming a Schiff base linkage?

• T subunit

• L subunit

• P subunit

• H subunit

What is the final product of serine catabolism?

• Acetyl CoA

• Glucose

• Pyruvate

• Citrate

During the catabolism of serine, which compound is released as a byproduct?

• NADH

• Water

• Ammonia

• Carbon dioxide

Which enzyme is involved in the dehydration of serine?

• Citrate synthase

• Glycine cleavage enzyme

• Serine dehydratase

• Threonine dehydrogenase

What is the fate of ammonia produced during amino acid catabolism?

• It is excreted as urea

• It is stored in the liver

• It is converted to glucose

• It is used in ketone body synthesis

Which amino acids are considered glucogenic based on their degradation to pyruvate?

• Glycine and serine

• Threonine and alanine

• Leucine and lysine

• Tryptophan and cysteine