Figure 1: monosaccharide
|
Carbohydrates |
Carbohydrates are broken down
into: Monosaccharaides, disaccharides, oligosaccharides and polysaccharides. These
are all essential in giving the animal the appropriate amount of energy (puri,
2005). The structure
always follows a ratio of 1-2-1 of Carbon, hydrogen and oxygen. They have a linear format. In either a chain
or ring form. A lot of saccharides structures are different in orientation of the
hydroxyl group (-OH). This difference has a huge impact on biochemical
properties, organoleptic properties and physical properties (melting point) and
specific rotation. The chain monosaccharide that has a carbonyl group (C=O) on
the rear end of carbon creating an aldehyde group (-CHO) is known as an aldose.
If the carbonyl group is on the inside atom it creates a ketone (known as a
ketose). The ribose ring is part of ribonucleic acid (RNA). deoxyribose is part
of deoxyribonucleic acid (DNA). In a nucleic acid the hydroxyl group is
connected to carbon number 1 and is exchanged with nucleotide bases (Sinnott,
2007).
Function
Carbohydrates are needed in the body in order to give energy. You can get these from a number of sources. Carbohydrates can be metabolized and are one of the main nutrients that are utilized in the animal's body.
Simple carbohydrates are glucose and are converted and used as energy in the animal's body. When this is the case different macronutrients are utilised for other jobs for example, growth and repair of tissues (when macronutrients are converted to protein).
Monosaccharide
Monosaccharaides are carbohydrates. This is the simplest structure of carbohydrates with 1 molecule of sugar. Examples of monosaccharides are galactose, glucose and fructose All monosaccharides follow the formula C6H12O6. They have 3 to 7 carbons and the molecules break down easily. The structure is a white, crystalline structure with a singular ketone (aldehyde) group. They are quick releasing energy.
The carbon skeleton has one carboxyl(C=O) functional group, and one hydroxyl (OH) group on each of the left over carbon atoms.
Carbon is made up of hydrogen and oxygen. This is similar to water. Carbohydrates are polyhydroxyl aldehydes and ketones (organic compound consisting of carboxyl group =C=O bonded to a hydrocarbon groups, created by oxidizing secondary alcohols as they have this in their structure. Aldehyde is an organic compound consisting of the group –CHO and are created by oxidation of alcohols.
Hexose (simple sugars); glucose and fructose have a chemical formula C6H12O6. Have 6 carbons.
They are then separated into two sections (ketoses and aldoses) depending on if they are ketones or aldehydes. They are known as tetrose, triose, hexose, pentose and heptose depending on how many carbon atoms they are made up of (three, four, five, six and seven). Heptose has 7 carbons. Pentoses have 5 carbon sugars with the formula being C5 H10 O5. Isomers which are carbohydrates have different compounds but are made up of the same chemical formula (Cheeke, 2010).
When glucose (dextrose) is in the body it is stored as glycogen in the animal's muscles and liver. Glucose is an aldehyde and fructose is a ketone (Sinnott, 2007). Glucose and fructose have the same chemical formula. (C6 H12 O6). Glucose is further broken down in the cells to produce ATP. Fructose is in a ring and chain form. Fructose is broken down in the liver and the left over parts are kept as fat.
Lactose: glucose, fructose, ribose; milk butter dairy products.
Di Saccharides
Di-saccharides are created when two monosaccharides join together. This is known as a glycosidic linkage (covalent bond). Examples of these are Maltose, sucrose and lactose.
Glucose + fructose=sucrose
Glucose+ Galactose= Lactose
Glucose+ Glucose= Maltose
Lactose: milk, dairy products. Maltose: corn sweet potato and barley.
(Disaccharide, 2015).
All disaccharides have a formula of C12H22O11. Maltose, is created when starch is broken down, it is essential for barley malt. Lactose is present in milk. Very young animals have an enzyme called lactase that aids in digestion of lactose. When a lot of animals get older they struggle to digest lactose. Disaccharides for example, lactose are large molecules, they cannot be absorbed by the small intestine. Before lactose can be absorbed, it needs to be broken down into the smaller monosaccharides. For this to happen, the small intestine creates an enzyme called lactase. The function of lactase is to connect itself to the lactose molecule and hydrolyze it into glucose and galactose. These smaller molecules can easily be absorbed by the intestines and enter the blood stream.
Sugar (sucrose) is a disaccharide and is taken from sugar beet/ cane. Sucrose is the sweetest disaccharide. Sugar has been swapped with corn syrup that comes from corn starch that is broken down polysaccharide (glucose). An isomerase enzyme has been created to change almost half glucose into fructose (Sand, 2010). Fructose major source of energy (corn starch) used in muscles and liver.
Bonding
Disaccharides are made by a condensation reaction of two simple sugar molecules. Condensation is where there is a loss of water in a chemical reaction. There are two OH groups one from each sugar molecule, connect together to let out water and create an oxygen bridge between. One of the OH groups is connected to the anomeric carbon; this is a carbon that has two oxygen bonds. Sucrose- is created by a 6 membered structure of glucose and 5 membered structure of fructose. (1,2 glycosidic bond).
Maltose- comes from the coupling of two molecules of glucose. It is created by the enzyme amylase breaking down starch. Made up of 2 glucose monomers.
Lactose- in milk made up of glucose and galactose have a glycosidic bond.
Function
Carbohydrates are needed in the body in order to give energy. You can get these from a number of sources. Carbohydrates can be metabolized and are one of the main nutrients that are utilized in the animal's body.
Simple carbohydrates are glucose and are converted and used as energy in the animal's body. When this is the case different macronutrients are utilised for other jobs for example, growth and repair of tissues (when macronutrients are converted to protein).
Monosaccharide
Monosaccharaides are carbohydrates. This is the simplest structure of carbohydrates with 1 molecule of sugar. Examples of monosaccharides are galactose, glucose and fructose All monosaccharides follow the formula C6H12O6. They have 3 to 7 carbons and the molecules break down easily. The structure is a white, crystalline structure with a singular ketone (aldehyde) group. They are quick releasing energy.
The carbon skeleton has one carboxyl(C=O) functional group, and one hydroxyl (OH) group on each of the left over carbon atoms.
Carbon is made up of hydrogen and oxygen. This is similar to water. Carbohydrates are polyhydroxyl aldehydes and ketones (organic compound consisting of carboxyl group =C=O bonded to a hydrocarbon groups, created by oxidizing secondary alcohols as they have this in their structure. Aldehyde is an organic compound consisting of the group –CHO and are created by oxidation of alcohols.
Hexose (simple sugars); glucose and fructose have a chemical formula C6H12O6. Have 6 carbons.
They are then separated into two sections (ketoses and aldoses) depending on if they are ketones or aldehydes. They are known as tetrose, triose, hexose, pentose and heptose depending on how many carbon atoms they are made up of (three, four, five, six and seven). Heptose has 7 carbons. Pentoses have 5 carbon sugars with the formula being C5 H10 O5. Isomers which are carbohydrates have different compounds but are made up of the same chemical formula (Cheeke, 2010).
When glucose (dextrose) is in the body it is stored as glycogen in the animal's muscles and liver. Glucose is an aldehyde and fructose is a ketone (Sinnott, 2007). Glucose and fructose have the same chemical formula. (C6 H12 O6). Glucose is further broken down in the cells to produce ATP. Fructose is in a ring and chain form. Fructose is broken down in the liver and the left over parts are kept as fat.
Lactose: glucose, fructose, ribose; milk butter dairy products.
Di Saccharides
Di-saccharides are created when two monosaccharides join together. This is known as a glycosidic linkage (covalent bond). Examples of these are Maltose, sucrose and lactose.
Glucose + fructose=sucrose
Glucose+ Galactose= Lactose
Glucose+ Glucose= Maltose
Lactose: milk, dairy products. Maltose: corn sweet potato and barley.
(Disaccharide, 2015).
All disaccharides have a formula of C12H22O11. Maltose, is created when starch is broken down, it is essential for barley malt. Lactose is present in milk. Very young animals have an enzyme called lactase that aids in digestion of lactose. When a lot of animals get older they struggle to digest lactose. Disaccharides for example, lactose are large molecules, they cannot be absorbed by the small intestine. Before lactose can be absorbed, it needs to be broken down into the smaller monosaccharides. For this to happen, the small intestine creates an enzyme called lactase. The function of lactase is to connect itself to the lactose molecule and hydrolyze it into glucose and galactose. These smaller molecules can easily be absorbed by the intestines and enter the blood stream.
Sugar (sucrose) is a disaccharide and is taken from sugar beet/ cane. Sucrose is the sweetest disaccharide. Sugar has been swapped with corn syrup that comes from corn starch that is broken down polysaccharide (glucose). An isomerase enzyme has been created to change almost half glucose into fructose (Sand, 2010). Fructose major source of energy (corn starch) used in muscles and liver.
Bonding
Disaccharides are made by a condensation reaction of two simple sugar molecules. Condensation is where there is a loss of water in a chemical reaction. There are two OH groups one from each sugar molecule, connect together to let out water and create an oxygen bridge between. One of the OH groups is connected to the anomeric carbon; this is a carbon that has two oxygen bonds. Sucrose- is created by a 6 membered structure of glucose and 5 membered structure of fructose. (1,2 glycosidic bond).
Maltose- comes from the coupling of two molecules of glucose. It is created by the enzyme amylase breaking down starch. Made up of 2 glucose monomers.
Lactose- in milk made up of glucose and galactose have a glycosidic bond.
Figure 2: disaccharide
Oligosaccharides
Oligosaccharides are carbohydrates that consist of three to ten mono-saccharides. These are complex carbohydrates.
Some types of Oligosaccharides are:
Pentose (ribose, arabinoses and xylose)
Arabinoxylans; primary and secondary cell wall of plants. (cereal grains) They are a mixture of xylose and arabinose.
Pentoses have 5 carbon sugars. The formula is C5H10O5. Examples of these are ribose, arabinoses and xylose. They are made up of a number of monosaccharides connected by glycosidic linkage that is hydrolyzed by acid and enzymes. Oligosaccharides are part of fibre.
Other oligosaccharides are sucrose, lactose and maltose.
When there are branched oligosaccharides, the structure is made up of at least one monosaccharide substance connected to two or more other monosaccharide substances. (Kim, 2010). Oligosaccharides are connected together by o-glycosidic bonds by a condensation reaction between anomeric carbon of a monosaccharide and the other. They can make N-glycosidic connections under a particular condition.
Some oligosaccharides occur due to the breakdown of larger polysaccharides e.g. starch and cellulose. The undigested portion serves as food for the intestinal micro flora. Depending on oligosaccharide, different bacterial groups are activated or suppressed. Giving insulin can increase the number of these beneficial bacteria in the colon and decrease the population of harmful bacteria. They are used in a lot of animal feeds to improve gastrointestinal health, energy levels and performance (kim, 2010).
Oligosaccharides are carbohydrates that consist of three to ten mono-saccharides. These are complex carbohydrates.
Some types of Oligosaccharides are:
Pentose (ribose, arabinoses and xylose)
Arabinoxylans; primary and secondary cell wall of plants. (cereal grains) They are a mixture of xylose and arabinose.
Pentoses have 5 carbon sugars. The formula is C5H10O5. Examples of these are ribose, arabinoses and xylose. They are made up of a number of monosaccharides connected by glycosidic linkage that is hydrolyzed by acid and enzymes. Oligosaccharides are part of fibre.
Other oligosaccharides are sucrose, lactose and maltose.
When there are branched oligosaccharides, the structure is made up of at least one monosaccharide substance connected to two or more other monosaccharide substances. (Kim, 2010). Oligosaccharides are connected together by o-glycosidic bonds by a condensation reaction between anomeric carbon of a monosaccharide and the other. They can make N-glycosidic connections under a particular condition.
Some oligosaccharides occur due to the breakdown of larger polysaccharides e.g. starch and cellulose. The undigested portion serves as food for the intestinal micro flora. Depending on oligosaccharide, different bacterial groups are activated or suppressed. Giving insulin can increase the number of these beneficial bacteria in the colon and decrease the population of harmful bacteria. They are used in a lot of animal feeds to improve gastrointestinal health, energy levels and performance (kim, 2010).
Figure 3: oligosaccharide
Polysaccharides
Poly- saccharides are multiple monosaccharaides Fibre, Glycogen, cellulose and starch are poly-saccharides. Polysaccharides are polymeric carbohydrate molecules made up of long chains of monosaccharide units connected together by glycosidic linkages. Molecular structure branched or linear and are difficult to break down.
Starch is made up of two parts: amylopectin and Amylose. Amylose consists of straight glucose chains and amylopectin has glucose chains that are branched. (20-30 residues). Cellulose is created by linking B-glucopyranose rings and glycogen and starch have a-glucopyranose rings.
Fibre has enzymes that mammals cannot digest. They are used as bacteria in the gastrointestinal tract, it is needed for allows for a healthy gut.
Glycogen and cellulose are polymetric carbohydrates created by repetitive units in two categories disaccharides or monosaccharaides. They are linked together by glycosidic bonds. Glycogen has a-(1-4) linkage and has 8-10 residues.
Cellulose is the most common structural polysaccharide. This is a linear polymer of glucose substances, where the structure is similar to amylose. It has a rigid structure. A lot of animals cannot digest cellulose as they do not have an enzyme that can have B-linkages between glucose molecules. Cellulose in the diet is used as fibre (roughage) (Benkeblia, 2014). When all monosaccharaides in polysaccharides are the same the polysaccharide is known as a homopolysaccharide. More than one monosaccharide known as heteropolysacchaide.
Chitin is an improved polysaccharide that consists of Nitrogen and comes from glucose and creates the external skeleton in a number of animals (biodegradable).
Pectin is a heteropolysacchaide (makes primary cell walls of plants). Pectin sources: oats, dried beans, nuts, barley, carrots. Starch: vegetables. Cellulose: fruit and vegetables. Pectins are gelling agents.
Poly- saccharides are multiple monosaccharaides Fibre, Glycogen, cellulose and starch are poly-saccharides. Polysaccharides are polymeric carbohydrate molecules made up of long chains of monosaccharide units connected together by glycosidic linkages. Molecular structure branched or linear and are difficult to break down.
Starch is made up of two parts: amylopectin and Amylose. Amylose consists of straight glucose chains and amylopectin has glucose chains that are branched. (20-30 residues). Cellulose is created by linking B-glucopyranose rings and glycogen and starch have a-glucopyranose rings.
Fibre has enzymes that mammals cannot digest. They are used as bacteria in the gastrointestinal tract, it is needed for allows for a healthy gut.
Glycogen and cellulose are polymetric carbohydrates created by repetitive units in two categories disaccharides or monosaccharaides. They are linked together by glycosidic bonds. Glycogen has a-(1-4) linkage and has 8-10 residues.
Cellulose is the most common structural polysaccharide. This is a linear polymer of glucose substances, where the structure is similar to amylose. It has a rigid structure. A lot of animals cannot digest cellulose as they do not have an enzyme that can have B-linkages between glucose molecules. Cellulose in the diet is used as fibre (roughage) (Benkeblia, 2014). When all monosaccharaides in polysaccharides are the same the polysaccharide is known as a homopolysaccharide. More than one monosaccharide known as heteropolysacchaide.
Chitin is an improved polysaccharide that consists of Nitrogen and comes from glucose and creates the external skeleton in a number of animals (biodegradable).
Pectin is a heteropolysacchaide (makes primary cell walls of plants). Pectin sources: oats, dried beans, nuts, barley, carrots. Starch: vegetables. Cellulose: fruit and vegetables. Pectins are gelling agents.
Figure 4: polysaccharide
Digestibility
Monosaccharaides can only be absorbed from the gastrointestinal tract with the exception of new-borns which are able to absorb bigger molecules. For absorption to happen tri, poly and disaccharides have to be hydrolysed by digestive enzymes by the host. The higher section of the small intestine jejunum and duodenum is where the greatest absorption of monosaccharides occurs (Gislason, 2011). Enzymes that breakdown carbohydrates hydrolyse the majority of complex carbohydrates to monosaccharides (Apart from when they have glucose e.g. cellulose).
Tract digestibility for dogs values are 97-99 percent. Mono, di and oligosaccharides (sugars) non-fibre carbohydrates. They are quickly fermented by the rumen, yielding microbial cells, organic acids, gas, and microbial glycogen. Compared to starch, fermentation of sugars appears to yield more or less microbial protein to the animal depending upon the relative rate microbial protein production Vs. rate of passage from the rumen and other limiting factors.
Cows
In cows the majority of ingested carbohydrates (starches) go straight into the small intestine prior to being broken down. Monosaccharides and disaccharides are connected by rumen microorganisms and used as an energy supply. Amylase breakdown of starches occurs in the small intestine.
Lions
In lions sucrase activity does not change between young and adults even when carbohydrates are included in the diet. Maltose activity is higher than sucrase.Lactase activity is highest in young. There are two types of lactase in lion intestinal mucosa, the pH of one is 4 or lower. This type of lactase is lysosome enzyme that does not involve lactose digestion. There is no lactase or sucrase in pancreatic tissue of lions. However, intestinal mucosa (lining of the intestinal tract), sucrase, maltase and isomaltase enzyme activities get higher from the duodenum to the jejunum and ileum. There are very low amounts of maltase activities in the small intestine mucosa of a lion (Pond, 2004).
Lions can digest very easily single units of sugar and cooked starch. Lactose can be digested to a certain amount. The indigestible polysaccharides are gathered as roughage and dietary fibre. Too much fibre can cause decreased absorption of minerals and not enough will cause diabetes and diarrhoea. Glucose can be constructed from protein if there is enough in the diet.
Lions have a small colon and their cecum does not work to its full potential since they cannot use these as well as other animals can. The digestibility of fibre of cellulose was 8.9 percent (Kim, 2010).
Starch is digested by a chicken by pancreatic alpha-amylase in the small intestine. Intestinal villi have enterocytes that show microvilli with a fibrous glycocalyx at the surface.
Chewing breaks food into small molecules that mix with saliva let out by the salivary glands in the mouth. Along with mucin and buffers, saliva consists of the enzyme salivary amylase, which works on the starch in food and breaks it down to maltose. Salivary amylase carries on for the short period that the carbohydrates are in the mouth, after this the mixture of the slightly digested carbohydrates transports down the esophagus into the stomach. Due to the inhibition of salivary amylase activity by the acidic gastric juices, digestion of carbohydrates does not occur in the stomach.
Gastric juices and slightly digested food goes into the small intestine, the pancreas lets out pancreatic juices, which consist of the enzyme pancreatic amylase. This enzyme works on the left over polysaccharides and breaks them into disaccharide units of maltose. In the last step of complex carbohydrate digestion, the enzyme maltase that is in the lining of the small intestine breaks maltose into two units of glucose. Glucose is then absorbed and goes into the bloodstream (Kim, 2010).
Digestibility
Monosaccharaides can only be absorbed from the gastrointestinal tract with the exception of new-borns which are able to absorb bigger molecules. For absorption to happen tri, poly and disaccharides have to be hydrolysed by digestive enzymes by the host. The higher section of the small intestine jejunum and duodenum is where the greatest absorption of monosaccharides occurs (Gislason, 2011). Enzymes that breakdown carbohydrates hydrolyse the majority of complex carbohydrates to monosaccharides (Apart from when they have glucose e.g. cellulose).
Tract digestibility for dogs values are 97-99 percent. Mono, di and oligosaccharides (sugars) non-fibre carbohydrates. They are quickly fermented by the rumen, yielding microbial cells, organic acids, gas, and microbial glycogen. Compared to starch, fermentation of sugars appears to yield more or less microbial protein to the animal depending upon the relative rate microbial protein production Vs. rate of passage from the rumen and other limiting factors.
Cows
In cows the majority of ingested carbohydrates (starches) go straight into the small intestine prior to being broken down. Monosaccharides and disaccharides are connected by rumen microorganisms and used as an energy supply. Amylase breakdown of starches occurs in the small intestine.
Lions
In lions sucrase activity does not change between young and adults even when carbohydrates are included in the diet. Maltose activity is higher than sucrase.Lactase activity is highest in young. There are two types of lactase in lion intestinal mucosa, the pH of one is 4 or lower. This type of lactase is lysosome enzyme that does not involve lactose digestion. There is no lactase or sucrase in pancreatic tissue of lions. However, intestinal mucosa (lining of the intestinal tract), sucrase, maltase and isomaltase enzyme activities get higher from the duodenum to the jejunum and ileum. There are very low amounts of maltase activities in the small intestine mucosa of a lion (Pond, 2004).
Lions can digest very easily single units of sugar and cooked starch. Lactose can be digested to a certain amount. The indigestible polysaccharides are gathered as roughage and dietary fibre. Too much fibre can cause decreased absorption of minerals and not enough will cause diabetes and diarrhoea. Glucose can be constructed from protein if there is enough in the diet.
Lions have a small colon and their cecum does not work to its full potential since they cannot use these as well as other animals can. The digestibility of fibre of cellulose was 8.9 percent (Kim, 2010).
Starch is digested by a chicken by pancreatic alpha-amylase in the small intestine. Intestinal villi have enterocytes that show microvilli with a fibrous glycocalyx at the surface.
Chewing breaks food into small molecules that mix with saliva let out by the salivary glands in the mouth. Along with mucin and buffers, saliva consists of the enzyme salivary amylase, which works on the starch in food and breaks it down to maltose. Salivary amylase carries on for the short period that the carbohydrates are in the mouth, after this the mixture of the slightly digested carbohydrates transports down the esophagus into the stomach. Due to the inhibition of salivary amylase activity by the acidic gastric juices, digestion of carbohydrates does not occur in the stomach.
Gastric juices and slightly digested food goes into the small intestine, the pancreas lets out pancreatic juices, which consist of the enzyme pancreatic amylase. This enzyme works on the left over polysaccharides and breaks them into disaccharide units of maltose. In the last step of complex carbohydrate digestion, the enzyme maltase that is in the lining of the small intestine breaks maltose into two units of glucose. Glucose is then absorbed and goes into the bloodstream (Kim, 2010).