Protein Metabolism and Urea Cycle

These flashcards summarize key concepts related to protein metabolism, amino acids, and the urea cycle to aid in exam preparation.

What are the two nutritionally non-essential amino acids synthesized from other amino acids or ammonia?

Serine and glycine are examples of nutritionally non-essential amino acids that can be synthesized from precursors.

Which amino acid is known as the 21st genetically encoded amino acid?

Selenocysteine (Sec) is the 21st genetically encoded amino acid.

What are the main categories of amino acids based on their polarity?

Amino acids can be categorized as nonpolar, polar uncharged, and charged.

Name one condition that can arise from amino acid deficiency states.

Kwashiorkor and Marasmus are conditions that can arise from amino acid deficiencies.

What is the role of methionine in the synthesis of cysteine?

Methionine donates sulfur for the synthesis of cysteine.

What is transamination?

Transamination is the major process for removing nitrogen from amino acids, where an amino group is transferred to α-ketoglutarate.

Which two amino acids are the main carriers of nitrogen in the blood?

Alanine and glutamine are the major carriers of nitrogen in the blood.

What is the net reaction of the urea cycle?

The net reaction of the urea cycle is 2 NH3 + CO2 + 3 ATP + H2O → Urea + 2 ADP + 4 Pi + AMP.

In which organ does urea biosynthesis primarily occur?

Urea biosynthesis primarily occurs in the liver.

What activates the first step of the urea cycle?

N-acetyl glutamate acts as an activator for the first step of the urea cycle.