Chemistry behind Digestion of Food

What happens after You eat?

All humans depend heavily on food for their survival. The meal is mechanically broken down into smaller bits after intake, and then through the action of enzymes, it is chemically digested. Chewing is merely a portion of the digestive process. Digestion enzymes break down food as it moves from your mouth into your digestive system, transforming it into more easily absorbed nutrients. Chemical digestion is the term for this disintegration. Your body wouldn't be able to take in nutrients from the food you eat without it.

As you now know, mechanical digestion is a fairly easy process. Food is physically broken down but its chemical composition is unaffected. Contrarily, chemical digestion is a sophisticated process that breaks down food into its chemical constituents, which are then absorbed to provide the body's cells with nutrition. 

What does chemical digestion serve?

Large amounts of food must be broken down during digestion into micronutrients that can be absorbed by cells. Peristalsis and chewing both aids in this but do not sufficiently reduce particle size. Chemical digestion can help with it. Different nutrients, including proteins, lipids, nucleic acids, and carbohydrates are examples of large food molecules that need to be broken down into smaller subunits in order to be absorbed by the lining of the alimentary canal.

Monosaccharides are formed when polysaccharides, or carbohydrate sugars, are broken down.

Amino acids are formed through protein breakdown.

Fatty acids and monoglycerides are the byproducts of fat breakdown.

Nucleotides are formed from nucleic acids.

Your body wouldn't be able to absorb nutrients without chemical digestion, which would result in vitamin shortages and malnutrition. Certain digestive enzymes are deficient in some persons. For instance, individuals with lactose intolerance typically produce insufficient amounts of lactase, the enzyme needed to digest the lactose protein found in milk. 

What Places Experience Chemical Digestion?

Your digestive system undergoes chemical digestion. Some foods start to break down chemically while they are still in your mouth. Saliva has the chemical capacity to break down some big molecules, such as carbohydrates, but it struggles to digest proteins. Your small intestine is where the process is finished after continuing in your stomach. Your stomach is where proteins begin to be chemically digested. In the stomach, the digestion of fats and carbohydrates continues (lipids are the chemical components of fat). All of the food you've eaten is starting to break down as gastric acids are released from your stomach. Some medications, like aspirin and some types of alcohol, can also be absorbed into the stomach. Your small intestine handles the bulk of chemical digestion. Your stomach stores the broken-down food in an acidic liquid called chyme. The small intestine receives chyme one dose at a time.

How are carbs metabolized?

Carbohydrates start to break down as soon as food enters your mouth. As you chew food, the saliva produced by your salivary glands moistens the meal. The amylase enzyme, which is released by saliva, starts the breakdown of the sugars in the carbohydrates you're ingesting. After the meal has been chewed into tiny pieces, you then swallow it. Your esophagus carries the carbohydrates to your stomach. The food is referred to as chyme at this point. Before the chyme moves on to the next stage of digestion, your stomach produces acid to destroy the bacteria there. The duodenum, the first segment of the small intestine, receives the chyme after leaving the stomach. The pancreas releases pancreatic amylase as a result. The chyme is converted into dextrin and maltose by this enzyme. From there, lactase, sucrase, and maltase production in the small intestine wall starts. The sugars are subsequently broken down by these enzymes into monosaccharides, or single sugars. These sugars are the ones that the small intestine finally absorbs. After being absorbed, they are further digested by the liver and then stored as glycogen. The bloodstream carries other glucose throughout the body. The pancreas releases the hormone insulin, which enables the body to use glucose as fuel.

How are proteins metabolized?

Proteins are polymers made up of long chains of amino acids connected by peptide bonds. They are broken down into their basic amino acids during digestion. Typically, you eat between 15 and 20 percent of your total calories as protein.

Proteins are first broken down into smaller polypeptides by pepsin in the stomach, where HCl denatures the proteins. These smaller polypeptides are then transported to the small intestine to complete the process of protein digestion. Pancreatic enzymes, such as trypsin, chymotrypsin, and carboxypeptidase, which each act on particular bonds in amino acid sequences, continue chemical digestion in the small intestine. The brush border's cells also release enzymes like aminopeptidase and dipeptidase, which further disassemble peptide chains.

How are lipids metabolized?

A balanced diet keeps lipid intake to no more than 35% of total calories. Triglycerides, which are composed of a glycerol molecule coupled to three fatty acid chains, are the most prevalent dietary lipids. Additionally, very few levels of phospholipids and dietary cholesterol are eaten. Lingual lipase, gastric lipase, and pancreatic lipase are the three lipases that break down lipids. But since the pancreas is the only organ that produces any significant amounts of lipase, almost all lipid digestion takes place in the small intestine. Each triglyceride is broken down by pancreatic lipase into two free fatty acids and a monoglyceride. Both short-chain (less than 10 to 12 carbons) and long-chain fatty acids are present in the fatty acids.

How are nucleic acids metabolized?

The majority of the foods you eat include the nucleic acids DNA and RNA. They are broken down by two different forms of pancreatic nuclease: deoxyribonuclease, which breaks down DNA, and ribonuclease, which breaks down RNA. Two intestinal brush border enzymes (nucleosidase and phosphatase) further break down the nucleotides created by this digestion into pentoses, phosphates, and nitrogenous bases that can be absorbed through the alimentary canal wall.

The meal enters the big intestine after your body has completed digesting it and absorbing its nutrients. The fecal matter is generated by this organ drawing water out of the digestive juices. The only components of your food left at this phase are those that your body was unable to digest or absorb. One food item that endures during the entire digestive process is fiber. Before they are naturally sent to your anus by contractions, feces can stay in your large intestine for one to two days.