Amino Acid Synthesis

Question 1

What three intermediate molecule pathways are used to synthesize amino acids?

Answer 1

1. 3-phosphoglycerate -> Phophoenolpyruvate -> Pyruvate
2. alpha-ketoglutarate and OAA f/m TCA
3. Ribose-5-phosphate and erythrose-5-phosphate f/m pentose phosphate pathway

Question 2

What are the three transamination reactions?

Answer 2

A. Pyruvate/Alanine exchange (SGPT)
B. OAA/Aspartate exchange (SGOT)
C. Alpha-ketoglutarate/Glutamate exchange by glutarate dehydrogenase

Question 3

What are the different fates of synthesized Aspartate?

Answer 3

• Used for protein synthesis
• Glutamine donates -NH3 to convert to Asparagine
• In some organisms, modifed to become lysine, methionine, and threonine

Question 4

How is glutamine synthesis regulated?

Answer 4

• Glutamate is converted to glutamine by Glutamate Synthetase
• Uses ATP created by breakdown of UTP;
• Adenylylation deactivated glutamien synthetase
• Phophates from deadenylylation are used to generated UTP f/m UMP

Question 5

What are fates of glutamate in amino acid synthesis?

Answer 5

• Glutamine formed to transport free NH4+ to Liver
• Proline formed by reduction and cyclization
• reduction + transamination -> Ornithine –> Arginine

Question 6

What are the amino acid derivatives of 3-phosphoglycerate?

Answer 6

• Serine
• Glycine (uses Vitamin B)
• Serine –> Cysteine

Question 7

What amino acids are synthesized using the Pentose Phosphate Pathway?

Answer 7

Aromatic Amino Acids:

• Histidine
• Tryptophan
• Phe
• Tyrosine

** E4P + PEP –> Chorismate

Question 8

What is the common derivative of branched amino acids like Val, Leu, and Ile?

Answer 8

Pyruvate

Question 9

What two amino acids are central to construction of most AA derivatives?

Answer 9

• Glycine and Serine

Question 10

What AA plays an important role in construction of Heme?

Answer 10

Glycine

Question 11

What body chemicals are derived from Glutamate?

Answer 11

• Glutathione (antioxidant)
• Polynesia (stabilize DNA)
• GABA (nt)

Question 12

What are some important Arginine-derived Molecules?

Answer 12

• NO (free radical)

- Creatinine phosphate

Question 13

What is the most important derivative of Methionine?

Answer 13

SAM - Primary methyl donor in most of the body

Question 14

What important body chemicals are derived from Histidine?

Answer 14

• Histamine

Question 15

What body chemicals are derivatives of tryptophan?

Answer 15

• Serotonin

- Melatonin

Question 16

What body chemicals are derived from Tyrosine?

Answer 16

Catecholamines:

• Epinephrine/Norep
• Dopamine