The purpose of digestion is to take the nutrients in the food you eat and make them available in a favorable form so they can be absorbed into the blood and transferred by the blood and the lymph system wherever they need to go to sustain life, rebuild cells, make new cells, and repair any damage that has been done.
Food starts the whole digestive process in the mouth. We actually begin the process by chewing the food, which adds saliva to it. The body operates in a water medium. Saliva can be 99% water. However, there are some enzymes involved as well – mainly ptyalin. This is called salivary or alpha-amylase, and it is a starch-splitting enzyme. Enzymes are primarily proteins in nature, and they have a specific job in digestion.
They grab onto food and tear it apart so it may be further digested. The enzymes themselves are not normally destroyed in this process. They are just there to aid and enhance. The food we eat contains proteins, fats, carbohydrates, and some minerals. The residue or roughage left over is necessary for the bulk of the gastrointestinal tract, as you will learn as this journey continues.
Keep in mind that when you eat a steak, that steak is composed of protein.
This protein is “steak protein,” and it was compiled and arranged in a particular network combination of amino acids that were good for the steak. When you eat it, your body has to begin to break it down all the way to its raw material and then reassemble it for your specific body. You will rebuild the amino acids to become a part of you.
And you are unique.
In the mouth, starch is acted upon, with only 10-15% of that starch being digested there with the salivary amylase. The ultimate end product of starch is sugar glucose, which is the fuel your cells use. For example, the starch in a potato must be broken down into glucose so your body can use it for fuel.
If you eat starch like a potato and chew it in your mouth, only 10-20% of it will be digested there before you continue the process by swallowing. Once you have taken the starch into your mouth, the ptyalin has been secreted to digest that starch in a certain concentration. That’s why it’s so important not to drink water (or anything) while eating. If you take in water at this time, you are diluting the concentration and, therefore, passing from normal digestion to one of indigestion (or incomplete digestion).
Once you swallow the potato, it goes into the stomach and on to the next phase in the journey of digestion. Watch for Anatomy of Digestion Part 2 – the Stomach next week!