When is maltose produced

It has to be further broken down into its saccharide constituents before it can be taken up by the enterocytes, into the bloodstream, and finally, to the cells of other tissues, such as liver, kidney, muscles, brain, adipose, etc. Maltose is digested and broken down into its monosaccharide units through hydrolysis with the help of the enzyme, maltase.

The bond that joins the two glucose units is broken, converting maltose to two glucose units. The free glucose molecules can now be absorbed by the enterocytes intestinal cells , released into the bloodstream, and then taken up by other cells. Maltose intolerance is one of the metabolic disorders associated with maltose. During digestion, the enzyme maltase is released from the gut lining to catalyze the breakdown of maltose into glucose constituents.

Low maltase enzyme activity results in the undigested maltose. When the body fails to digest maltose, it draws water from the body into the intestine. This leads to diarrhea. In the colon, the gut flora metabolizes the undigested maltose. This, in turn, causes bloating and pain. Maltose intolerance is extremely rare in humans. It is typically associated with the lack of sucrase-isomaltase enzymes. Dietary disaccharides are consumed and digested so as to obtain simple sugars that are readily absorbed and metabolized.

Maltose is one of the main sources of glucose. Glucose is a crucial nutrient since it is used chiefly in energy metabolism.

Maltose forms starch. Starch and maltose are structurally similar in a sense that they are made up of glucose units. However, starch is a polymer of glucose whereas maltose is a disaccharide of glucose.

Nevertheless, maltose usually comes from the digestion or hydrolysis of starch. In particular, two glucose units i. This is what occurs, for instance, in germinating seeds. Maltose is commercially used as a sweetener, a nutrient in infant feeding, and in bacteriological culture media. It is also used in pastries. It makes bread dough to rise when carbon dioxide is produced and released during the conversion of starch into maltose by reacting the starch with enzyme s. As a sweetener, it has less sweetness than other typical sugars.

However, maltose consumption is not advisable to diabetics because of its high glycemic index. Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats.

If you want an overview of the different carbohydrates and fats the body needs, read this tutorial Read More. The body is comprised of different elements with hydrogen, oxygen, carbon, and nitrogen as the major four. This tutorial will help you understand the chemical composition of the body.

This will come in handy when considering the various interactions between cells and structures. Digestive Enzymes. Skip to content Main Navigation Search. Dictionary Articles Tutorials Biology Forum. Table of Contents. A Balanced Diet — Carbohydrates and Fat Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats. Chemical Composition of the Body The body is comprised of different elements with hydrogen, oxygen, carbon, and nitrogen as the major four.

Related Articles The large molecules found in intact food cannot pass through the cell membranes. Food needs to be broken into smaller particles so that animals can harness the nutrients and organic molecules.

The first step in this process is ingestion. Ingestion is the process of taking in food through the mouth. In vertebrates, the teeth, saliva, and tongue play important roles in mastication preparing the food into bolus. While the food is being mechanically broken down, the enzymes in saliva begin to chemically process the food as well.

The combined action of these processes modifies the food from large particles to a soft mass that can be swallowed and can travel the length of the esophagus. Digestion is the mechanical and chemical break down of food into small organic fragments. It is important to break down macromolecules into smaller fragments that are of suitable size for absorption across the digestive epithelium. Large, complex molecules of proteins, polysaccharides, and lipids must be reduced to simpler particles such as simple sugar before they can be absorbed by the digestive epithelial cells.

Different organs play specific roles in the digestive process. The animal diet needs carbohydrates, protein, and fat, as well as vitamins and inorganic components for nutritional balance. How each of these components is digested is discussed in the following sections. The digestion of carbohydrates begins in the mouth. The salivary enzyme amylase begins the breakdown of food starches into maltose, a disaccharide. As the bolus of food travels through the esophagus to the stomach, no significant digestion of carbohydrates takes place.

The esophagus produces no digestive enzymes but does produce mucous for lubrication. The acidic environment in the stomach stops the action of the amylase enzyme. The next step of carbohydrate digestion takes place in the duodenum. Recall that the chyme from the stomach enters the duodenum and mixes with the digestive secretion from the pancreas, liver, and gallbladder. Pancreatic juices also contain amylase, which continues the breakdown of starch and glycogen into maltose, a disaccharide.

The disaccharides are broken down into monosaccharides by enzymes called maltases , sucrases , and lactases , which are also present in the brush border of the small intestinal wall.

Maltase breaks down maltose into glucose. Other disaccharides, such as sucrose and lactose are broken down by sucrase and lactase, respectively. The monosaccharides glucose thus produced are absorbed and then can be used in metabolic pathways to harness energy. The monosaccharides are transported across the intestinal epithelium into the bloodstream to be transported to the different cells in the body. The steps in carbohydrate digestion are summarized in Figure 1 and Table 1.

Figure 1. Digestion of carbohydrates is performed by several enzymes. Starch and glycogen are broken down into glucose by amylase and maltase. Sucrose table sugar and lactose milk sugar are broken down by sucrase and lactase, respectively.

A large part of protein digestion takes place in the stomach. The enzyme pepsin plays an important role in the digestion of proteins by breaking down the intact protein to peptides, which are short chains of four to nine amino acids. In the duodenum, other enzymes— trypsin , elastase , and chymotrypsin —act on the peptides reducing them to smaller peptides. Trypsin elastase, carboxypeptidase, and chymotrypsin are produced by the pancreas and released into the duodenum where they act on the chyme.

Further breakdown of peptides to single amino acids is aided by enzymes called peptidases those that break down peptides. Specifically, carboxypeptidase , dipeptidase , and aminopeptidase play important roles in reducing the peptides to free amino acids.

The amino acids are absorbed into the bloodstream through the small intestines. The steps in protein digestion are summarized in Figure 2 and Table 2.

Figure 2. Protein digestion is a multistep process that begins in the stomach and continues through the intestines. Lipid digestion begins in the stomach with the aid of lingual lipase and gastric lipase.

However, the bulk of lipid digestion occurs in the small intestine due to pancreatic lipase. When chyme enters the duodenum, the hormonal responses trigger the release of bile, which is produced in the liver and stored in the gallbladder. Bile aids in the digestion of lipids, primarily triglycerides by emulsification.

Emulsification is a process in which large lipid globules are broken down into several small lipid globules. These small globules are more widely distributed in the chyme rather than forming large aggregates. Lipids are hydrophobic substances: in the presence of water, they will aggregate to form globules to minimize exposure to water. Bile contains bile salts, which are amphipathic, meaning they contain hydrophobic and hydrophilic parts.

Thus, the bile salts hydrophilic side can interface with water on one side and the hydrophobic side interfaces with lipids on the other.

By doing so, bile salts emulsify large lipid globules into small lipid globules. Why is emulsification important for digestion of lipids?

Pancreatic juices contain enzymes called lipases enzymes that break down lipids. If the lipid in the chyme aggregates into large globules, very little surface area of the lipids is available for the lipases to act on, leaving lipid digestion incomplete. By forming an emulsion, bile salts increase the available surface area of the lipids many fold. The pancreatic lipases can then act on the lipids more efficiently and digest them, as detailed in Figure 3.