3. Physiology
        3.9. Metabolism and Nutrition
            3.9.1. Metabolism
3.9.1.3. Protein metabolism

Protein metabolism

Structures

Primary structure - amino acid sequence

Secondary structure - protein twisting and folding
* e.g. alpha-helix, beta-sheet

Tertiary structure - arrangement of chains and sheets into layers, crystals, fibres

Quaternary structure - Arrangement of subunits

 

Tidbits
Amino acids

Essential amino acids

Ketogenic amino acids

Glucogenic amino acids

 

Uric acid

... is formed from

  1. breakdown of purine
  2. by direct synthesis from 5-phosphoribosyl pyrophophate (5-PRPP) and glutamine

98% of filtered uric acid is reabsorbed

Active secretion by tubules

About 1g/24h is excreted
* 80% of is by active secretion

Gout

... is due to increased blood uric acid level causing urate deposit in joints and other tissues.

Primary gout

Secondary gout

Colchicine - doesn't affect uric acid metabolism but relieves gout attacks by inhibiting the phagocytosis of uric acid crystals by leukocytes

Allopurinol - inhibits xanthine oxidase (which otherwise converts xanthine into uric acid).

 

 

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