Biochemicals
Protein metabolism and related compounds are crucial for life, and imbalances can lead to many diseases. This overview ties together protein biochemistry with human health, covering metabolic pathways, disease, and molecular properties
Biochemical Theory and Metabolic Pathways
- Proteins as Building Blocks: Essential for structure, enzymes, transport, immunity
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Key Metabolic Pathways
- Protein Synthesis: Amino acids are linked to make proteins
- Protein Degradation: Proteins are broken down into amino acids
- Amino Acid Metabolism: Amino acids can be recycled or used for other molecules
- Transamination: Transfer of amino groups
- Deamination: Removal of amino groups (produces ammonia)
- Urea Cycle: Conversion of toxic ammonia to urea for excretion
- Creatine Metabolism: Production and use of creatine for muscle energy
- Other Nitrogen-Containing Molecules: Nucleotides, hormones, neurotransmitters
Normal and Abnormal States
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Normal States
- Nitrogen Balance: Intake = excretion
- Normal Protein Turnover: Balanced synthesis and breakdown
- Adequate Levels: Normal Amino acid levels
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Abnormal States
- Protein-Energy Malnutrition (PEM): Marasmus (calorie deficiency) and Kwashiorkor (protein deficiency)
- Amino Acid Disorders: Genetic defects (e.g., PKU)
- Urea Cycle Disorders: Elevated ammonia
- Hyperammonemia: Elevated ammonia in blood
- Proteinuria: Excess protein in urine
- Hypoproteinemia: Low protein in blood
Physical and Chemical Properties
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Proteins
- Complex 3D structure (primary, secondary, tertiary, quaternary)
- Amphoteric (can act as acid or base)
- Subject to denaturation
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Amino Acids
- Building blocks of proteins
- Amphoteric
- Linked by peptide bonds
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Urea
- End product of nitrogen metabolism
- Water-soluble
- Excreted in urine
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Uric Acid
- End product of purine metabolism
- Sparingly soluble
- Can form crystals (gout)
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Creatinine
- Waste product from muscle creatine
- Water-soluble
- Excreted by kidneys
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Ammonia
- Toxic breakdown product of amino acids
- Converted to urea in liver
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Tumor Markers (CEA, PSA, AFP, CA 125)
- Proteins or glycoproteins
- Associated with cancer
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Cardiac Markers (Troponin, CK-MB, Myoglobin)
- Proteins released during heart damage