It is hard to overemphasize the necessity of nutrients. In our community of cells, many billions of cells are repaired and replaced every hour. In an analogy that our cells are like a community of underwater houses, repairing or replacing this number cells would be the equivalent of rebuilding all of the houses and buildings that exist on earth each and every day. On the molecular scale, the need for supplies to keep up this kind of construction project is enormous and the demand for the fuel necessary to keep it running is also enormous. It is amazing that our bodies are able to handle it all and keep it coordinated. How do these nutrients get into the cells that need them? How are they apportioned? What happens if there is a shortage or an overabundance of one important nutrient or another? How are the nutrients placed and assembled into the instruments and structures that are needed after they arrive and are admitted into the cells? All of these questions are answered through study of the nutrient pathways. Arguably, these pathways are a bit more complex than oxygen pathways; there are several kinds of nutrients and each have different pathways. But surprisingly, the whole picture is not quite as complex as you might think.

Below is a list of some of the most important macronutrient and micronutrient molecules utilized by our body and their basic categories. We will unravel these briefly so they are not so daunting to understand and we will take a closer look at a few of them later on:

Sugars (Polysaccharides):

Fructose, Galactose, Glucose, Lactose, Maltose, Sucrose | Source: Grains, berries, fruits, Milk | Function: Immediate source of fuel for the cells

Amino Acids:

Alanine , Arginine, Aspartic acid (aspartate), Asparagine, Cystine, Glutamic acid (glutamate), Glutamine, Glycine, Histidine, Isoleucine (branched chain), Leucine (branched chain), Lysine, Methionine, Phenylalanine, Proline, Serine, Threonine, Tryptophan, Tyrosine, Valine (branched chain) | Source: All foods  | Function: Basic building blocks for proteins and structures in the cell, the “lego” blocks of the cell.

Saturated Fatty Acids:

Butyric acid (C4), Caproic acid (C6), Caprylic acid (C8), Capric acid (C10), Lauric acid (C12), Myristic acid (C14), Pentadecanoic acid (C15), Palmitic acid (C16), Margaric acid (C17), Stearic acid (C18), Arachidic acid (C20), Behenic acid (C22), Lignoceric acid (C24), Cerotic acid (C26) | Source: Vegetable oils, nut oils, bean oils, seed oils, margarines | Function: Fuel storage often packaged into glycerides, Free Fatty Acids are the primary source of fuel for cells.

Mono Unsaturated Fats:

Myristol, Pentadecenoic, Palmitoyl, Heptadecenoic, Oleic acid, Eicosen, Erucic acid, Nervonic acid | Source: Leafy vegetable oils | Function: Light sources of energy and serve as supplies and messengers in cells.

Polyunsaturated Fatty Acids:

Linoleic acid (LA, essential Omega 6), α-Linolenic acid (ALA, essential Omega 3), Stearidonic acid (SDA), Arachidonic, acid (ETA), Timnodonic acid (EPA), Clupanodonic acid (DPA), Cervonic acid (DHA) | Source: Fish oils, olive oils, grain oils | Function: Materials for cell structures and instruments, can also serve as fuel if needed.

Minerals:

Calcium, Chloride, Magnesium, Phosphorus, Potassium, Sodium, Iron, Sulphur, Boron, Cobalt, Chromium, Copper, Fluoride, Iodine, Manganese, Molybdenum, Selenium, Zinc | Source: Fresh water, grasses, lettuces, greens | Function: Form important components of the instruments played in the cell.

Organic Acids:

Acetic acid, Citric acid, Lactic acid, Malic acid, Choline, Taurine | Source: citrus, milk, beans | Function: Intermediate players produced by instruments.

Vitamins:

Vitamin A (retinol), C (Ascorbic acid), D, E (tocopherol), K, B1 (thiamin), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 group (Pyridoxine, Pyridoxal, Pyridoxamine), B7 (biotin), B8 (ergadenylic acid), B9 (folic acid), B12 (cyanocobalamin), Choline | Source: Various foods | Function: Basic supplies needed by cellular instruments and players, including genetic processes.

Carotenoids:

Alpha carotene, Beta carotene, Cryptoxanthin, Lutein, Lycopene, Zeaxanthin | Source: Carrots, squashes, bell peppers, tomatoes | Function: Colorful antioxidants that protect plants and animals from sunlight radiation.

Flavonoids:

Epicatechin, Hesperidin, Naringin, Oligomeric proanthocyanidins, Quercetin, Rutin, Tangeritin | Source: Nuts, apples, fruits, olives | Function: Antioxidants and raw materials used by animals and plants.

Not all of the nutrients on this list are exclusively provided by our diet. Many of these can also be assembled inside our cells from other types of nutrients and supplies; specialized molecular machines can build many important nutrients from the other molecular supplies that originate from our diet.  There are even molecular machines in our fluids and cells that can convert some of the nutrients on this list from one type to another (for example, sugars can be converted into fatty acids, and fatty acids can be converted into sugars). Some of these nutrients on this list, however, are classified as “essential” nutrients, meaning that they cannot be made inside our cells and must be exclusively provided by our diet.

If you are getting the feeling that you can think of cells as little molecular manufacturing facilities that have the capacity to build and remodel molecules from the nutrients and supplies around them, you are getting the right idea. Keep in mind that all of this manufacturing and remodeling of molecules requires supplies and energy; the fuels that supply this energy also come from the nutrients provided by our diet.