protein Metabolism كامل
Page 1: Biochemistry Overview
Focus on proteins and metabolism.
Page 2: Scientific Committee Trabal 42
Participants included Abtahal Tam, Faris Wadi, and others.
Page 3: Protein Digestion
Proteins are denatured by gastric HCl producing primary structure via:
Gastric HCl: Provides acidic environment (pH 1-2.5), denatures proteins.
Pepsinogen: Inactive form, activates to pepsin (proteolytic enzyme).
Rennin: Active in infants.
Intestinal Proteolytic Enzymes:
Pancreatic secretions include bicarbonate, trypsinogen (activated to trypsin), and others for final digestion.
Page 4: Classification of Proteolytic Enzymes
Endopeptidases: Pepsin, Trypsin.
Exopeptidases: Carboxypeptidase, Aminopeptidase.
Enzymatic breakdown leads to free amino acid absorption.
Page 5: Absorption of Proteins
Types of transport systems:
Sodium amino acid carrier system.
Gamma glutamine system.
Amino acids transport concentration gradients toward the blood.
Major roles in liver for plasma proteins and hormones.
Page 6: Hormones and Functions
Oxytocin: Uterine contraction and milk secretion (9 amino acids).
Insulin: Lowers blood sugar, facilitates glucose usage.
Neurotransmitters: GABA (from glutamic acid) and others.
Page 7: Transamination & Deamination
Transamination: Involves ALT and AST enzymes, critical for amino acid metabolism.
Deamination: Free ammonia removal; important for amino acid recycling and urea cycle initiation.
Page 8: Enzyme Significance
Elevated AST/ALT may indicate liver diseases or myocardial infarction (heart attack).
Page 9: Ammonia and Urea Cycle
Normal ammonia levels < 0.01 mg; excess causes toxicity (hepatic coma).
Urea is excreted and produced chiefly in liver.
Page 10: Dietary Proteins
Main nitrogen source; amino acids utilized for protein synthesis and energy metabolism.
Page 11: Proteolytic Enzymes Overview
Enzymatic role in protein digestion begins in the stomach and is essential for nutrient absorption.
Page 12: Gastric HCl Function
Aids in protein denaturation and creates favorable conditions for enzymatic action.
Page 13: Pepsin Activation
Pepsinogen is converted to active pepsin, critical for protein digestion in acidic environments.
Page 14: Pancreatic Enzymes
Bicarbonate is vital for neutralizing gastric acid for optimal enzyme activity in the duodenum.
Page 15: Enzyme Specificity
Trypsin: Activates several other digestive enzymes from zymogens.
Chymotrypsin: Complements trypsin's function.
Page 16: Intestinal Enzymatic Action
Intestinal enzymes finalize protein digestion into absorbable amino acids.
Page 17: Amino Acid Absorption Transport Mechanisms
Two main transport systems are involved in amino acid absorption through the intestine.
Page 18-22: Ammonia Sources and Detoxification
Ammonia from deamination and bacterial activity needs detoxification; converted into urea for excretion.
Page 23: NF urea Cycle
The cycle occurs primarily in the liver and involves removal of toxic ammonia.
Page 24-25: Urea Regulation
Factors regulating urea cycle activity include liver capacity and ammonia levels.
Page 26-30: Amino Acid Metabolism Overview
Synthesis of essential compounds and metabolism pathways for aliphatic amino acids.
Page 31-39: Metabolism of Sulfur-Containing Amino Acids
Synthesized from serine; key roles in protein structure and metabolism.
Page 40-41: Metabolism of Aromatic Amino Acids
Disorders associated with aromatic amino acids focus on phenylalanine and tyrosine.
Page 42-48: Catecholamines and Thyroid Hormones
Functions and hormones provided by adrenal and thyroid glands, effects on metabolism.
Page 49-50: Uric Acid and Purine Metabolism
Conversion processes and significance in human health, with emphasis on gout and related conditions.
Page 51-56: Review Questions & Key Concepts
A summary of essential terminology, metabolic pathways, and clinical relevance of amino acids.
Page 57-58: Acknowledgments
A note of thanks for assistance in compiling the content.