Amino acid metabolism II. The urea cycle Figures: Lehninger-4ed; chapter: 18 Stryer-5ed; chapter: 23.

Slides:



Advertisements
Similar presentations
Protein Turnover and Amino Acid Catabolism
Advertisements

Chapter 5 - Cell Respiration and Metabolism Metabolism - the sum of all the chemical reactions that occur in the body. It is comprised of:  anabolism.
Urea Cycle DR AMINA TARIQ BIOCHEMISTRY. Urea is the major disposal form of amino groups derived from amino acids, and accounts for about 90% of the nitrogen-
Detoxification of ammonia and biosynthesis of urea. The basic features of nitrogen metabolism were elucidated initially in pigeons.
Amino acid oxidation and the production of urea
1 LECTURES CATABOLISM OF PROTEINS AND AMINO ACID NITROGEN DR SAMEER FATANI BIOCHEMISTRY (METABOLISM)
Chapter 17 - Amino Acid Metabolism
Nitrogen Metabolism Copyright  2013 Pearson Canada Inc
Amino Acids Metabolism: Disposal of Nitrogen.
Fate of Ammonia Unit -0 By Dr. Abdulrahman Al-Ajlan.
Amino Acid Catabolism C483 Spring Which of the following is/are true statement(s) about glutamine and alanine? A) They are nitrogen donors in.
1 Metabolism of Amino Acids. Part II Richard D. Howells, PhD Dental Biochemistry Lecture 24.
Dr. Saidunnisa Hans Krebs Associate Professor Department of Biochemistry Ammonia metabolism and Urea Cycle.
METABOIC FATE OF AMINO ACIDS. Intracellular proteases hydrolyze internal peptide bonds, of protein releasing peptides, which are then degraded to free.
Role of Amino Acids Protein monomeric units Energy source Precursors of other biological molecules Protein monomeric units Energy source Precursors of.
Nucleotide Catabolism. Overview of Nucleotide Catabolism Ingested nucleotides are not incorporated into nucleic acids Normal nucleic acid turnover.
How Cells Release Stored Energy
Catabolic Pathways 2 nd Year Physiotherapy By Eman Mokbel Alissa, Ph.D.
Protein Catabolism ?Can you give me some examples of what chemicals you think youve used, or how you think chemistry may have impacted your life?
Digestion of Proteins 25.7 Degradation of Amino Acids 25.8 Urea Cycle Chapter 25 Metabolic Pathways for Lipids and Amino Acids.
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 18 Metabolic.
Protein Metabolism. generation of metabolic energy A mino acids, through their oxidative degradation, make a significant contribution to the generation.
Gluconeogenesis Dr. Tarek A Salem.
Cell Respiration Chapter 5. Cellular Respiration Release of energy in biomolecules (food) and use of that energy to generate ATP ENERGY (food) + ADP +
Pyruvate Oxidation and Krebs Cycle
Amino acid metabolism · Nitrogen balance protein catabolism, synthesis biosynthesis normal N balance: N ingested = N excreted negative N balance: N ingested.
ADP, ATP, and Cellular Respiration
Amino acid degradation Most of absorbed dietary amino acids are catabolized by 2 subsequent steps: I- Removal of α-amino group: α-amino group is removed.
CHAPTER 9 ENERGY METABOLISM. LEARNING OUTCOMES Explain the differences among metabolism, catabolism and anabolism Describe aerobic and anaerobic metabolism.
Overview of Glucose Metabolism
The Urinary System & Excretion Detoxification of the Blood.
Chapter 5 Cell Respiration and Metabolism
Cellular Respiration Purpose: create a form of energy useable by the cell Like Getting an Allowance.
Cellular Respiration Chapter 8.3. Animal Plant Mitochondria.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint.
BIOC/DENT/PHCY 230 LECTURE 5. glu UREA o synthesised mainly in liver o maintains N in a soluble, non-toxic form o transported in blood to kidney for.
BIOC/DENT/PHCY 230 LECTURE 6. Nucleotides o found in DNA and RNA o used for energy (ATP and GTP) o building blocks for coenzymes (NADH)
NS 315 Unit 4: Carbohydrate Metabolism Jeanette Andrade MS,RD,LDN,CDE Kaplan University.
Nitrogen Cycle. Summary of Protein and Amino Acid Metabolism.
22-1 Principles and Applications of Inorganic, Organic, and Biological Chemistry Denniston, Topping, and Caret 4th ed Chapter 22 Copyright © The McGraw-Hill.
17.8 Amino Acid Catabolism Amino acids from degraded proteins or from diet can be used for the biosynthesis of new proteins During starvation proteins.
Amino acid metabolism IV. Biosynthesis of nonessential amino acids Figures: Lehninger-4ed; fejezet: 22 (Stryer-5ed; fejezet: 24)
Amino Acid Degradation and Nitrogen Metabolism
NS 315 Unit 4: Carbohydrate Metabolism Jeanette Andrade MS,RD,LDN,CDE Kaplan University.
The Urea Cycle. TCA cycle HOW UREA CYCLE WORKS?
Biology 105 Chapter 8: How cells make ATP Pgs Chapter 8: How cells make ATP Pgs
LEHNINGER PRINCIPLES OF BIOCHEMISTRY Fifth Edition David L. Nelson and Michael M. Cox © 2008 W. H. Freeman and Company CHAPTER 18 Amino Acid Oxidation.
Stage 3 Digestion Citric Acid Cycle Overview. Warm-up 1.Draw the entry level Rx of Glycolysis. 2.What’s the enzyme named catalyzing it? 3.Name the inhibitor.
Cellular Respiration 2 Structures and functions. Respiration Three step process: Glycolysis (all living cells) Krebs cycle (higher animals) Electron transport.
NS 315 Unit 4: Carbohydrate Metabolism
AMINO ACIDS METABOLISM Course: MEDICIMAL CHEMISTRY 1 Course Code: 301.
LECTURE 10 Introduction to lipid metabolism and oxidation of fatty acids I V. SRIDEVI
1.The Nitrogen Cycle 2.Amino Acid Biosynthesis 3.Urea Cycle 4.Amino Acid Catabolism 5.Molecules Derived from Amino Acid (from Lehninger P )
Enter in the formation of A.A. pool
CELLULAR RESPIRATION Definition
Obtaining Energy from Food
بايو كمستري / د . احمد ثاني اسنان موصل 19 / 4 / 2016
24.7 Urea Cycle The ammonium ion, the end product of amino acid degradation, is toxic if it is allowed to accumulate. The urea cycle converts ammonium.
Amino Acid Metabolism.
Transdeamination (Deamination of L-Glutamic Acid)
RESPIRATION Prof Nirupama Mallick
Cellular Respiration Stages 2-4.
Biochemistry Lecture 14.
1. מעגל האוריאה 1 1.
Chapter 8 Section 3: Cellular Respiration
Nitrogen metabolism Part C:
Bio 178 Lecture 15 Cellular Respiration
Urea cycle and its significance
AL-Ma’moon University College Medical Laberatory techniques Department Clinical biochemistry / Second stage ASS.Lec. Suad Turky Ali (Lec – 1-)
AL-Ma’moon University College Medical Laberatory techniques Department Clinical biochemistry / Second stage ASS.Lec. Suad Turky Ali (Lec – 1-)
Presentation transcript:

Amino acid metabolism II. The urea cycle Figures: Lehninger-4ed; chapter: 18 Stryer-5ed; chapter: 23

Overview of amino acid catabolism in mammals

Excretory forms of nitrogen

In ureotelic organisms, the NH 3 deposited in the mitochondria of hepatocytes is converted to urea in the urea cycle. This pathway was discovered by Hans Krebs (citric acid cycle) and Kurt Henseleit. Urea production occurs almost exclusively in the liver and is the fate of most of NH 3 channeled there. Urea → bloodstream → kidneys → urine

Possible sources of ammonia ● Amino acid degradation in every organ, especially in the liver and muscles ● Ammonia secretion (5-10% of whole N turnover) in kidney tubules from glutamine (Chinese Restaurant) ● Nucleotide (pyrimidine) degradation ● Intestinal bacteria produce it from amino acids and urea Ammonia is very toxic → cerebral edema, increased cranial pressure (depletion of ATP in brain cells?)

Links between the urea cycle and citric acid cycle

The energetic cost of urea synthesis 2NH HCO 3 ¯ + 3ATP + H 2 O → urea + 2ADP + 4Pi + AMP + 2H + ● requires 4 high-energy phosphate groups ● NADH is produced in the malate dehydrogenase reaction (urea cycle ↔ citric acid cycle) ● NADH = 2.5 ATP (mitochondrial respiration)  The overall energetic cost of urea synthesis is reduced!

Regulation of the urea cycle