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Molecular Function

Classification based on what chemicals actually do

Different molecules play different roles in human beings

Gives different information about body function than organic molecular composition.

Molecular Function

Molecular Function

Here is a list of 20 common biologically functional types of molecules found in the human body, along with their approximate percentage by weight where possible:

  1. Water (H2O) - 60-75% of total body weight

  2. Proteins - 16-20% of total body weight Examples: enzymes, structural proteins, transport proteins

  3. Lipids - 10-15% of total body weight Examples: triglycerides, phospholipids, cholesterol

  4. Carbohydrates - 1-2% of total body weight Examples: glucose, glycogen, cellulose

  5. Nucleic acids - 1-2% of total body weight Examples: DNA, RNA

  6. Ions Examples: sodium (Na+), potassium (K+), calcium (Ca2+)

  7. Vitamins Examples: vitamin A, vitamin C, vitamin D

  8. Minerals Examples: iron, zinc, magnesium

  9. Hormones Examples: insulin, cortisol, estrogen

  10. Neurotransmitters Examples: dopamine, serotonin, acetylcholine

  11. Cofactors and coenzymes Examples: NAD+, FAD, coenzyme Q10

  12. Antioxidants Examples: glutathione, vitamin E, superoxide dismutase

  13. Enzymes Examples: amylase, protease, lipase

  14. Immunoglobulins (antibodies) Examples: IgA, IgG, IgM

  15. Cytokines Examples: interleukin-1, tumor necrosis factor, interferons

  16. Growth factors Examples: epidermal growth factor, insulin-like growth factor, nerve growth factor

  17. Extracellular matrix proteins Examples: collagen, elastin, fibronectin

  18. Peptide hormones Examples: oxytocin, vasopressin, growth hormone-releasing hormone

  19. Gaseous signaling molecules Examples: nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S)

  20. Metabolites Examples: pyruvate, lactate, citrate

Please note that the percentages provided are approximate values and can vary depending on factors such as age, sex, and overall health. Some categories may overlap, as certain molecules have multiple functions or belong to more than one category.

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