Objectives:

1. When more amino acids are ingested than are needed to replace protein and other nitrogenous compounds, what is their fate?
2. When muscle protein is catabolized in muscle during a fast, what are the fates of the amino acids?
3. What is another name for transamination reactions?
4. Be able to write a reaction for AST, ALT, or any other transamination reaction. What is the approximate Keq for these reactions?
5. What are the cofactors for ALT and AST. Are the coenzymes prosthetic groups? What vitamin are the cofactors derived from?
6. Around pH = 7.3, which is the most prevalent form, ammonia or ammonium ion? Use the pKa = 9.3 and the Henderson Hasselbalch Equation to prove it.
7. What are the major sources of free ammonium ion in the liver, muscle and other tissues?
8. Be able to write the glutamate dehydrogenase reaction. Is this reaction readily reversible?
9. Glutamate is important in the synthesis of nonessential amino acids. How does glutamate acquire the amino groups for this purpose?
10. Glutamate is important in the synthesis of urea. How does glutamate acquire the amino groups for this purpose? What does glutamate do with the amino groups?
11.When excess NH4+ is produced in most cells of the body, it can be combined with glutamate and transported to the liver where it is released as free NH4+. Name the two enzymes and the intermediate in this process.
12. Know the substrates, products, and five enzymes of the urea cycle. Which compartments are involved? What tissues are involved?
13. How is the urea cycle regulated?
14. How is the production of urea during a fast related to the need for blood glucose and the catabolism of muscle protein? How does the production of ketone bodies fit in?

15. Name 3 ways to treat argininosuccinate lyase deficiency and explain their rationale.
16. Concerning Percy Veere who has hepatitis A: What liver function tests were ordered? Why was the serum concentration of each substance increased?
17. Concerning Percy Veere who has hepatitis A: Name the enzymes and intermediates in the conversion of ammonium ion and a-ketoglutarate to glutamine in the brain.
18. Concerning Percy Veere who has hepatitis A: Why would a low protein diet, antibiotics, enemas and lactulose lower his blood ammonium ion level?

Keywords:

N-acetylglutamate, alanine, alanine aminotransferase, alanine transaminase, alkaline phosphatase, α-keto acid, α-ketoglutarate, ALT, ammonia, ammonium ion, AMP, arginase, arginine, argininosuccinate lyase, argininosuccinate, argininosuccinate synthetase, asparagine, asparaginase, aspartate, aspartate aminotransferase, aspartate transaminase. AST, ATP, benzoic acid, bicarbonate, carbamoyl phosphate, carbamoyl phosphate synthetase I, carbohydrate, citrulline, fat, fumarate, gluconeogenesis, glucose, glutamate, glutaminase, glutamine, glutamine synthetase, gut, ketone bodies, kidney, mitochondria, NAD(P)+, NAD(P)H, NH4 +, nitrogen, nonessential amino acids, ornithine, ornithine transcarbamoylase, PPi, protein, pyridoxine (B6), total bilirubin, transamination, urea, urea cycle, urease.

Assignments:

Understand the meaning of the key words in the context of Chapter 38.

Examine Questions (Q:) and Answers (A:) in Chapter 38.

Work Review Questions 1, 2, 3, and 5 at the end of the Chapter 38 but not Questions 4.

Work the Practice Questions for Chapter 38 Objectives

Other Help:

No Other Help for Chapter 38