Animal Biology MJ1 Life Processes PDF

COURSE: MJ1 LIFE PROCESSES AND ANIMAL BIOTECHNOLOGY MODULE 1 : LIFE PROCESSES-I Mrunmayi Rane  Syllabus 1.2 Nutrition 1.2.1 Apparatus for nutrition: 1.2.2 Animals without alimentary canal, ex. Amoeba 1.2.3 Animals with incomplete alimentary cana...

COURSE: MJ1 LIFE PROCESSES AND ANIMAL BIOTECHNOLOGY MODULE 1 : LIFE PROCESSES-I Mrunmayi Rane  Syllabus 1.2 Nutrition 1.2.1 Apparatus for nutrition: 1.2.2 Animals without alimentary canal, ex. Amoeba 1.2.3 Animals with incomplete alimentary canal, ex. Hydra, 1.2.4 Animals with complete alimentary canal, ruminants and non ruminants 1.2.5 Brief account of physiology of digestion in vertebrates and symbiotic digestion in ruminants. Mrunmayi Rane  INTRODUCTION TO NUTRITION AND NURTITIONAL APPARATUS Nutrition is the process that involves intake food and converting it into energy and other vital nutrients required for the maintenance of life processes.” Nutritional apparatus refers structures (organs) and mechanisms (processes) involved in the obtaining nutrition. Major macromolecules that supply energy: Carbohydrates, Proteins and Lipids (Fats). Mrunmayi Rane Animals without Alimentary Canal. ex. Amoeba Mrunmayi Rane  Amoeba : Introduction Classification: 1.Domain: Eukaryota ▪ Amoeba is a unicellular organism. 2.Kingdom: Amoebozoa ▪ Microscopic, size around 2 micron to 2 mm in 3.Phylum: Tubulinea diameter. 4.Order: Tubulinida ▪ Simple eukaryotic, asymmetrical organism. ▪ Moves around through Pseudopodia- false feet. 5.Family: Amoebidae ▪ Habitat: Freshwaters such as ponds and rivers, 6.Genus: Amoeba few species are marine. ▪ The typical lifespan of an Amoeba is only 2 days. Mrunmayi Rane  Structure of Amoeba Amoeba’s entire body is transparent and gelatin-like. Body of Amoeba is mainly divided into three basic parts – cytoplasm, plasma membrane and nucleus. The cytoplasm contains cellular organelles like a contractile vacuole, mitochondria, Golgi apparatus and fat globules are enclosed within a cell membrane. The DNA is present in the nucleus, which is covered with a plasmalemma. The cytoplasm is further differentiated into two layers – the outer ectoplasm and the inner endoplasm. Mrunmayi Rane  Nutrition in Amoeba They feed on bacteria, plant cells, algae, protozoa etc. It does not possess a well-defined mouth or anus. The food consumption process occurs via pinocytosis or phagocytosis. It shows Holozoic mode of nutrition. The process of digestion in Amoeba involves ingestion, digestion, absorption, assimilation, and egestion. Mrunmayi Rane  Food of Amoeba Bacteria Algae Protozoans Mrunmayi Rane  Major Organs involved in the process of digestion in Amoeba Being a single-celled organism, Amoeba is reported to have intracellular digestion. The finger-like projections, pseudopodia extend and engulf the food particle. Amoeba digests their food in the food vacuole. The food vacuole is formed due to ingestion and then fused with lysosomes. Amoeba contains membrane-bound organelles such as lysosomes that contain hydrolytic enzymes like proteases, glycolytic enzymes, nucleases, and lipases. Mrunmayi Rane Phagocytosis in Amoeba Mrunmayi Rane  Process of Digestion in Amoeba Nutrition in an Amoeba takes place through a process also known as Phagocytosis, which is a special form of Endocytosis. In this process, the entire Amoeba engulfs the food/bacteria. It shows heterotrophic nutrition. Nutrition involves the following steps: ingestion, digestion, absorption, assimilation and egestion of food. The body surface of the amoeba takes part in the process as they do not have any specialized organs for nutrition. The first step is ingestion which is the process of engulfing food by swallowing inside the body through the process of phagocytosis. As it moves, it encounters food particles in the water. To grab the food, it extends its pseudopodia around it, surrounding and enclosing it within a food vacuole (a small sac inside the amoeba's cell). Mrunmayi Rane  Process of Nutrition in Amoeba The food vacuole then fuses with a lysosome containing digestive enzymes as proteases, nucleases, and lipases that help in break down of the food particles. The next step is digestion, where the mechanical and chemical breakdown of the ingested food takes place with the help of digestive enzymes. After digestion, the nutrients are absorbed. These nutrients are used for the growth and maintenance of cell. The excess food is stored as Glycogen or lipids for future use. Assimilation is the process of oxidation of food to gain the energy required for survival. Lastly, egestion takes place where the undigested food is excreted out of the cell through the same vacuole. Mrunmayi Rane  Useful Links: Amoeba: https://www.youtube.com/watch?v=7pR7TNzJ_pA&t=22s Structure of Amoeba: https://www.youtube.com/watch?v=0uafEyrE-20 Nutrition in Amoeba: https://www.youtube.com/watch?v=mv6Ehv06mXY Mrunmayi Rane Animals with Incomplete Alimentary Canal. ex. Hydra Mrunmayi Rane  Hydra : Introduction Hydra belongs to phylum Cnidaria & class Hydrozoa. Habitat: Freshwater. Little polyps with a body length of 1 to 20 mm. Tentacles above the body might number up to ten or twelve. It has capacity to regenerate. Basic structure includes a mouth, a peduncle, and a basal disc. Each tentacle, or cnida (plural: cnidae), is clothed with highly specialized stinging cells called cnidocytes. Cnidocytes contain specialized structures called nematocysts, which look like miniature light bulbs with a coiled thread inside. Mrunmayi Rane Structure of Hydra Mrunmayi Rane  Nutrition in Hydra Food Hydra is exclusively carnivorous. small aquatic animals such as insect larvae, crustaceans (e.g. Cyclops, Daphnia), and annelid worms. It may swallow prey larger than itself, such as young fish and tadpoles. Digestion is completed by following 4 steps. Mrunmayi Rane  Process of Digestion in Hydra 1. Ingestion Coelenterates/Cnidarians use nematocysts (stinging cells) for capturing animals. As the food comes in contact with nematocysts, it injects the poison in the prey’s body. Then paralyzed prey is brought towards the mucus-lined mouth, which opens widely to swallow it. The mucous secretion helps in swallowing. The contraction of the hypostome (mouth) and body wall (peristaltic movements) force the food down into the coelenteron (gastrovascular cavity) where the digestion takes place. Mrunmayi Rane  Process of Digestion in Hydra 2. Digestion The gastrovascular cavity acts as an enteron “intestine” where is both extracellular and intracellular digestion occurs. The single opening of this gastrovascular cavity is the mouth serving as both ingestion and egestion. This type of digestive system is known as the Incomplete digestive system. Mrunmayi Rane Digestion in Hydra Mrunmayi Rane  Process of Digestion in Hydra a. Extracellular digestion By the action of digestive juices secreted by the gland cells of the gastrodermis, the prey is killed. Churning movements caused by the expansion and contraction of the body wall mix up the digestive juices with food which is broken into smaller particles. The digestive enzymes now act upon the disintegrated food. A proteolytic enzyme like trypsin partly digests proteins into peptides. This type of digestion, occurring in the cavity, outside the gastrodermal cells, is called extracellular digestion which is purely proteolytic. Mrunmayi Rane  Process of Digestion in Hydra b. Intracellular digestion The smaller fragments of food are engulfed by nutritive-muscle cells by means of pseudopodia and digested within vacuoles. This is intracellular digestion. Studies have revealed that food vacuoles undergo both acidic and as well as alkaline phases, and digestion of protein is completed by other proteolytic enzymes. Digestion in Hydra combines both intracellular digestion of lower (Protozoa and Porifera), and extracellular digestion of vertebrates. Retention of intracellular digestion is probably due to its aquatic mode of life, as the digestive juices get diluted in the gastrovascular cavity. Mrunmayi Rane  Process of Digestion in Hydra 3. Absorption Once the digestion is completed, the nutrients are absorbed by endodermal cells and distributed by diffusion from cells to cells. The gastrovascular cavity serves for both digestion and circulation. Hydra can digest proteins, fats, and some carbohydrates but not starch. The reserve food materials, chiefly glycogen and fats, are stored in some of the gastrodermal cells. Mrunmayi Rane  Process of Digestion in Hydra 4. Egestion The indigestible residues, like the exoskeleton of crustacea, are egested through the mouth due to muscular contraction of the body. The mouth thus functions as the anus as well. Mrunmayi Rane  Useful Links https://www.sciencesource.com/2401242-hydra-digestive-tract- stock-video-rights-managed.html Feeding behaviour in Hydra : https://www.youtube.com/watch?v=yhb45dmLD1k https://www.youtube.com/watch?v=pdjzCWo-pTY Mrunmayi Rane Animals with Complete Alimentary Canal. ex. Ruminants Mrunmayi Rane  Nutrition in Ruminants Introduction: Ruminants are mammals of the suborder Ruminantia and order Artiodactyla. Which includes animals like Giraffes, Deer, Cattle, Anteopes, Sheep, and Goats. Most ruminants have a four-chambered stomach. Mrunmayi Rane Mrunmayi Rane  Ruminant Digestive Tract The ruminant digestive tract consists of the following organs: Mouth Oesophagus A four-compartment stomach, which includes The rumen The reticulum (“honeycomb”) The omasum The abomasum (“true stomach”) Small intestine Large intestine Rectum Anus Mrunmayi Rane Mrunmayi Rane Ruminant Digestive Tract Mrunmayi Rane  “Honeycomb” interior lining of the reticulum Interior lining of the rumen Mrunmayi Rane Interior lining of the omasum Interior lining of the abomasum, the “true stomach Mrunmayi Rane  Components of the Ruminant Digestive System 1. Mouth The digestive process begins here. Ruminants chew and grind down plant matter, mixing it with enzyme-filled saliva before swallowing. 2. Oesophagus After the plant material is chewed, the oesophagus begins waves of muscle contractions to move the food down towards the stomach. It moves in two directions (bidirectional), which allows the partially-chewed plant matter ('cud') to be regurgitated if the animal needs to grind the feed up more. Mrunmayi Rane  Components of the Ruminant Digestive System 3. Stomach Ruminant animals' stomachs have four sections: the rumen, reticulum, omasum, and abomasum. Each compartment has a particular job to do, including the storage of chewed food, absorption of nutrients and vitamins, the breakdown of proteins, and aiding in the start of digestion and the dissolution of materials into more manageable pieces. Mrunmayi Rane  Components of the Ruminant Digestive System a. Rumen It is the first part of the stomach and is connected to the oesophagus. It stores chewed grass and other vegetation and creates balls of cud. It also absorbs nutrients and assists with fermentation and the creation of rumen bacteria and rumen microbes needed to break down and digest proteins. The rumen and reticulum make up the majority of the stomach. b. Reticulum Frequently called the 'honeycomb,' this part of the stomach is attached to the rumen with thin tissue. Its function is to trap food material too large to digest. Mrunmayi Rane  Components of the Ruminant Digestive System c. Omasum This compartment of the stomach is lined with folds of tissue that are visually similar to a book. These 'leaves' of tissue absorb water and nutrients from feed that has been chewed twice over. d. Abomasum The abomasum, often called the 'true stomach,' is the last part of the ruminant stomach. It is the only part of the stomach lined with glands, which produce hydrochloric acid and digestive enzymes to further help the breakdown of plant material and feed. Each part of the ruminant stomach is a vital part of maintaining healthy digestion. Anything affecting one section's functionality can have a cascading effect on the digestive system and overall animal health. Mrunmayi Rane  Components of the Ruminant Digestive System 4. Small Intestine Comprising of three main sections — the duodenum, jejunum and ileum — the small intestine carries out most of the actual digestive process. The stomach connects to the duodenum, where the animal's gallbladder and pancreas secrete substances to help digest the food matter. The jejunum is lined with villi (finger-like structures) that increase intestinal surface area and helps to further absorb nutrients. Finally, the ileum functions to absorb vitamin B12, bile salts, and any nutrients that passed through the jejunum. A valve located at the end of the ileum prevents materials from flowing back. Mrunmayi Rane  Components of the Ruminant Digestive System 5. Large Intestine The large intestine is shorter in length but larger in diameter than the small intestine and is the last step in the digestive process. It carries out the function of absorbing remaining water and making use of bacteria and microbes to finish digestion and produce vitamins for the animal's growth and health. Finally, the large intestine pushes undigested and unabsorbed food in the form of waste to the next part i.e. rectum where the waste is stored for a temporary period and then thrown out of the body through anus. Mrunmayi Rane Physiology of Symbiotic Digestion in Ruminants Mrunmayi Rane  Need of four-chambered stomach Ruminants are unable to digest grasses, foliage, and other plant material directly, because their bodies do not produce enzymes capable of breaking down cellulose. Therefore they later regurgitate food material, called cud, and chew it again to further break down its cellulose content, which is difficult to digest. The chewed cud goes directly to the other chambers of the stomach (the reticulum, omasum, and abomasum), where it is further digested with the aid of various essential microorganisms that live in the stomach. Mrunmayi Rane  Need of four-chambered stomach These microorganisms secret the enzyme: cellulase required for the break down the cellulose in plant materials. Presence of microorganisms in the ruminant gut is an example of symbiotic relationship between the microbes and ruminants. Where microbes are benefitted with food and shelter and ruminants get the essential enzyme for the breakdown of cellulosic material. Mrunmayi Rane  Symbiotic Digestion in Ruminants The digestion process in ruminants begins by chewing and swallowing its food. Ruminants do not completely chew the food they eat, but just consume or gulp as much they can and then swallow the food. This is an adaptation by which these animals have evolved to spend as little time as possible feeding so that they are not hunted down by any predators while they are eating. The process of digestion begins with the first two chambers of the stomach, the rumen and reticulum by softening the ingested matter. Mrunmayi Rane  Symbiotic Digestion in Ruminants The rumen is the fermentation vat. As It contains a large number of microbes. It is the largest part of the stomach. Its internal surface is covered with projections called papillae, which provide a greater surface area for absorption as well as supporting the mechanical movement of food around the rumen. As it contains a large number of microbes. These microbes produce the cellulase enzyme required to digest in the plant material i.e. cellulose. This releases the sugars and nutrients within the plant cells by breaking the cell wall of plant. Mrunmayi Rane  Symbiotic Digestion in Ruminants The reticulum is next compartment after the rumen. Its main role is to act as a filter, trapping larger feed particles that require further digestion. These larger food particles are regurgitated and rechewed – a process called rumination – with more saliva. They are then swallowed into the rumen again. Small food particles go straight into the omasum. Mrunmayi Rane  Symbiotic Digestion in Ruminants The omasum is made up of lots of folds of tissue, almost like a leaf. This creates a large surface area to absorb water. It also acts as a filtration system and only allows fine particles and small amounts of fluid into the abomasum. The abomasum is also referred to as the true stomach. It has a low pH – an acidic environment that kills the bacteria that pass from the rumen and also provides acidic medium for functioning of stomach enzymes. The abomasum is where the digestion of proteins begins. Mrunmayi Rane  Symbiotic Digestion in Ruminants The small intestine is about 40 m long. pH in small intestine is basic/ alkaline due to secretions from the liver. Pancreatic enzymes require basic medium for proper functioning. It is provided by the bile secretions of liver. The surface of small intestine is covered with fine villi (finger- like projections). Once the digestion process is completed, these increased surface area, allows maximum absorption of nutrients. Mrunmayi Rane  Symbiotic Digestion in Ruminants The large intestine is the final part of the digestive tract. It is made up of the caecum and the colon. The main function of the large intestine is to absorb water and minerals. It also stores the waste products in rectum. Faeces are expelled through the anus. Mrunmayi Rane Animals with Complete Alimentary Canal. ex. Non-Ruminant (Human). Mrunmayi Rane  Digestive System in Man The process of digestion involves breaking down complex molecules into simpler molecules that can be readily absorbed by the body. Digestive system comprises : the alimentary canal and associated digestive glands. The processes of digestion include six activities: ingestion, propulsion, mechanical or physical digestion, chemical digestion (enzymatic digestion), absorption, and defecation. Mrunmayi Rane Human Alimentary Canal Mrunmayi Rane Mrunmayi Rane Flow chart of Human Alimentary Canal Mrunmayi Rane Human Alimentary Canal: Structure and Function 1. Mouth and Oesophagus Digestion begins in the mouth. The food is ground up by the teeth and moistened with saliva to make it easy to swallow. Saliva has an enzyme, called Salivary Amylase which starts breaking down starch into maltose. Once swallowed, muscular contractions of the Oesophagus massage the ball of food down into the stomach. It is a simple tube like structure. Also known as Food pipe. Mrunmayi Rane Human Alimentary Canal: Structure and Function 2. Stomach The stomach stores swallowed food, then mixes it with digestive juice which contains hydrochloric acid and pepsinogen (active form is pepsin). Then it slowly empties its contents, called chyme (semi- digested food), into the small intestine. The muscle of the upper part of the stomach relaxes to accept large volumes of swallowed material from the oesophagus. The muscle of the lower part of the stomach mixes the food with digestive juice. Mrunmayi Rane Human Alimentary Canal: Structure and Function 3. Small intestine Once in the duodenum, the food is mixed with more digestive enzymes from the pancreas and bile from the liver. Food is then squeezed into the lower parts of the small intestine, called the jejunum and the ileum. Nutrients are absorbed from the ileum, which is lined with millions of finger-like projections called villi. Each villus is connected to a mesh of capillaries. This is how nutrients pass into the bloodstream. Mrunmayi Rane Human Alimentary Canal: Structure and Function 4. Large intestine The large intestine absorbs water and any remaining nutrients and minerals. It then changes the waste from liquid into stool. The rectum stores stool until it pushes stool out of the body during a bowel movement. It is then passed out of the body through the anus. Mrunmayi Rane  Associated Digestive Glands 1.Salivary glands Saliva produced by the salivary glands moistens food so it moves more easily through the esophagus into the stomach. Saliva also contains an enzyme named as Salivary Amylase that begins to break down the starch from food into maltose. Mrunmayi Rane  Associated Digestive Glands 2. Glands in the stomach lining Stomach secretes conc. HCl. Which kills harmful pathogens that enters through food. It also provides acidic medium for the functioning of stomach enzyme called Pepsin that digests proteins. Mrunmayi Rane  Associated Digestive Glands 3. Liver The liver has a number of different roles in the body, including: a. breaking down fats (emulsification of fats), using bile stored in the gall bladder. b. processing proteins and carbohydrates. c. filtering and processing impurities, drugs and toxins. d. generation of glucose for short-term energy needs from other compounds like lactate and amino acids. Mrunmayi Rane  Associated Digestive Glands 4. Pancreas It secretes juices called pancreatic enzymes to break down food. These enzymes are emptied into the upper part of small intestine called the duodenum. The pancreatic lipolytic enzymes are lipase, phospholipase, and esterase, which digest fats. The glycolytic (carbohydrate digesting) enzymes are lactase and amylase, which breaks down starch into maltose, maltotriose, and dextrins. Enzymes such as trypsin, chymotrypsin which are proteolytic enzymes. Pancreatic enzymes require alkaline/basic pH for their functioning which is provided by bile. Mrunmayi Rane  Physiology of Digestion in Vertebrates (Human) The processes of digestion include six activities: ingestion, propulsion, mechanical or physical digestion, chemical digestion, absorption, and defecation. Mrunmayi Rane 1. Ingestion: ▪ The entry of food into the alimentary canal through the mouth is called ingestion. 2. Propulsion: ▪ Propulsion refers to the movement of food through the digestive tract. ▪ It includes both the voluntary process of swallowing and the involuntary process of peristalsis. Mrunmayi Rane 3. Mechanical Digestion: It is a purely physical process, it makes the food smaller to increase both surface area and mobility. It includes mastication, or chewing, as well as tongue movements that help break food into smaller bits and mix food with saliva. 4. Chemical digestion: ▪ Chemical digestion of food by enzymes present in secretions produced by glands and accessory organs of the digestive system. Mrunmayi Rane 5. Absorption: In this process, the nutrients are absorbed from the lumen of the alimentary canal into the bloodstream through the epithelial cells that make up the mucosa. 6. Elimination: Food substances that have been eaten but cannot be digested and absorbed are excreted by the bowel as feces. Mrunmayi Rane  Physiology Of Digestion in Human 1. In the Oral Cavity: After ingestion, the food is chewed and mixed with saliva, which contains enzymes that begin breaking down the carbohydrates plus some lipids via lingual lipase. Saliva contains the enzyme salivary amylase that begins the breakdown of complex sugars as starch, reducing them to the disaccharide maltose. Chewing by the teeth increases the surface area of the food and allows an appropriately sized bolus to be produced. Food leaves the mouth when the tongue and pharyngeal muscles propel it into the oesophagus. Mrunmayi Rane 2. Pharynx and Oesophagus: The presence of the bolus in the pharynx stimulates a wave of peristalsis which propels the bolus through the esophagus to the stomach. The walls of the esophagus are lubricated by mucus which assists the passage of the bolus during the peristaltic contraction of the muscular wall. The cardiac sphincter guarding the entrance to the stomach relaxes to allow the descending bolus to pass into the stomach. Mrunmayi Rane 3. In the Stomach: When a meal has been eaten the food accumulates in the stomach in layers, the last part of the meal remaining in the fundus for some time. Numerous gastric glands are situated below the surface in the mucous membrane of the stomach. They consist of specialized cells that secrete gastric juice into the stomach. Gastric juice has an acidic pH (around 1.5 to 3.5) and consists of water, mineral salts, mucus secreted by goblet cells, hydrochloric acid secreted by parietal cells, intrinsic factor, and inactive enzyme precursors: pepsinogens secreted by chief cells in the glands. The hydrochloric acid present in the juice acidifies the food and stops the action of salivary amylase, kills ingested microbes. Mrunmayi Rane  Further, pepsinogens are activated to pepsins by hydrochloric acid and by pepsins already present in the stomach. They begin the digestion of proteins, breaking them into polypeptides. Gastric muscle contraction consists of a churning movement that breaks down the bolus and mixes it with gastric juice and peristaltic waves that propel the stomach contents towards the pylorus. When the stomach is active the pyloric sphincter closes. Strong peristaltic contraction of the pyloric stomach forces gastric contents, after they are sufficiently liquefied, through the pylorus into the duodenum. Mrunmayi Rane 4. In the Small Intestine: When acidic chyme (partially digested food) passes into the small intestine it is mixed with pancreatic juice, bile, and intestinal juice. When a meal has been eaten the hormone CCK is secreted by the duodenum during the intestinal phase of secretion of gastric juice. This stimulates the contraction of the gall bladder and relaxation of the hepatopancreatic sphincter, enabling the bile and pancreatic juice to pass into the duodenum together. Mrunmayi Rane a. Digestion by Pancreatic Juice Pancreatic juice works in alkaline medium. When acidic stomach contents enter the duodenum they are mixed with pancreatic juice and bile and the pH is raised to between 6 and 8. This is the pH at which the pancreatic enzymes, amylase, and lipase, act most effectively. Digestion of proteins. Trypsinogen and chymotrypsinogen are inactive enzyme precursors activated by enterokinase, an enzyme in the microvilli, which converts them into the active proteolytic enzymes trypsin and chymotrypsin. These enzymes convert polypeptides to tripeptides, dipeptides, and amino acids. Digestion of carbohydrates. Pancreatic amylase converts all digestible polysaccharides (starches) not acted upon by salivary amylase to disaccharides. Digestion of fats. Lipase converts fats into fatty acids and glycerol. To aid the action of lipase, bile salts emulsify Mrunmayi fats. Rane b. Digestion by Bile Juice: Bile, secreted by the liver has a pH of 8 and between 500 and 1000 ml are secreted daily. It consists of water, mineral salts, mucus, bile salts, bile pigments (mainly bilirubin), and cholesterol. The bile salts, sodium taurocholate, and sodium glycocholate emulsify fats in the small intestine. The breakdown of fat globules in the duodenum into tiny droplets, which provides a larger surface area on which the enzyme pancreatic lipase can act to digest the fats into fatty acids and glycerol is called bile emulsification. Fatty acids are insoluble in water, which makes them very difficult to absorb through the intestinal wall. Bile salts also make fatty acids soluble, enabling both these and fat-soluble vitamins (e.g. vitamin K) to be readily absorbed. Mrunmayi Rane c. Digestion by Intestinal juice: Alkaline intestinal juice (pH 7.8 to 8.0) assists in raising the pH of the intestinal contents to between 6.5 and 7.5. Enterokinase activates pancreatic peptidases such as trypsin which convert some polypeptides to amino acids and some to smaller peptides. The final stage of breakdown to amino acids of all peptides occurs inside the enterocytes. Lipase completes the digestion of emulsified fats to fatty acids and glycerol partly in the intestine and partly in the enterocytes. Sucrase, maltase, and lactase complete the digestion of carbohydrates by converting disaccharides such as sucrose, maltose, and lactose to monosaccharides inside the enterocytes. Mrunmayi Rane  Thus, in the small intestine the digestion of all the nutrients is completed: carbohydrates are broken down to monosaccharides. proteins are broken down to amino acids. fats are broken down into fatty acids and glycerol. Mrunmayi Rane 5. In the Large Intestines: The large intestines are joined to the end of the small intestine at the cecum, via the ileocecal valve. In the large intestine absorption of water continues until the familiar semisolid consistency of feces is achieved. Mineral salts, vitamins, and some drugs are also absorbed into the blood capillaries from the large intestine. The large intestine descend to the rectum and ends at the anal canal. After the absorption of useful materials, the remaining waste material is stored as feces before being removed by defecation through the anus. Mrunmayi Rane  Quick Summary Major Processes involved the Digestion Mrunmayi Rane  Useful Link Digestion in Human https://www.youtube.com/watch?v=zSXgoYdHotw&t=2s Mrunmayi Rane