Animal Nutrition

Mouth: Where the food enters. Food has to enter somewhere before they can be digested right? There are other purposes of your mouth that isn’t biology related, and hence we won’t discuss it here. Salivary Glands: These secrete amylase, which breaks down starch into maltose, so the substance can more easily be digested. Esophagus & Stomach: : After the food has been digested, it is now in a round, small mass. It then travels down the esophagus and the stomach by a process called Peristalsis. Gastric juice in the stomach will then start digesting the protein. Small intestines:  After 1-2 hours a resulting thick liquid called chyme is produced. The chyme enters the duodenum, and is mixed with digestive enzymes in the pancreas. Eventually, this is passed down the small intestines. Chyme is absorbed into blood when digested. Water and minerals are reabsorbed into the blood in the colon. Liver: The liver produces bile, which emulsifies (mixture of two or more liquids) fats, to allow absorption. Bile is stored in the gallbladder where it is then released to small intestine via bile duct. Pancreas: Pancreas makes pancreatic juice. This secretes important enzymes for digestion such as amylase, pancreatic lipase, and forms of proteases. Anus: Stored feces are eliminated from the body through the anus, via the process egestion.

Amylase: Salivary glands and the pancreas Protease: Stomach Lipase: Primarily found in pancreas, but also found in mouth and stomach. 13.  State the functions of a typical amylase, a protease, and a lipase, listing the substrate and end products.These are all pancreatic enzymes which serve a specific function.Amylase: Breaking down complex carbohydrates into simple sugars. This is important so the body can use these sugars for energy (particularly respiration) Protease: There are many types of proteases, such as trypsin. However, you don’t really have to know that. In small intestine, protease guide with the breakdown of protein in amino acids Lipase Help digest fats Help with absorption of fat by breaking down triglycerides into fatty acids, which can easily be absorbed.

Absorption: Movement of digested food molecules through the wall of the intestine into the blood

Ingestion: taking substances into the body through the mouthEgestion: passing out of food that has not been digested as faeces through the anusDigestion: breakdown of large, insoluble food molecules into small soluble molecules using mechanical and chemical processes

bile emulsifies the fats into smaller droplets that cumulatively give them a larger surface area enabling more to be absorbed as more is exposed to the lipase. Hard before as lipids are hydrophobic = only lipids at the surface could be absorbed

 When food is in the stomach, it then travels to the small intestines The stomach is acidic, but the digestive enzymes in the small intestines work best in alkaline conditions Here is where bile comes in. Bile is an alkaline substance produce in the liver and then stored in the gallbladder Bile is then secreted in the small intestine, and its function is to “emulsify” fat, the purpose to give a larger surface area for the enzyme lipase to work on

Functions of teeth: Enamel: Covers tooth crown. Enamel is VERY hard (harder than bone), and prevents the tooth from decaying. Dentin: Located under the enamel, this looks quite similar to bone. Not as hard as enamel. Pulp: Found at center of tooth, and contains blood vessels, nerves and soft tissues which delivers nutrients to your tooth. Types of teeth:Incisors: Eight teeth at the front and center of food.Purpose: Cutting Chopping Canine:  You have four canines. Sharpest teethPurpose: Cutting Tearing Premolar :  You have four pre-molars on each side of your mouth.Purpose: Chewing Grinding Molars:  You have eight molars in total. Same function as premolar, just different location (refer to diagram)Purpose: Grinding Mashing

Causes: Tooth decay is caused by a combination of bacteria and food. A stick substance called plaque which contains bacteria is constantly being formed in your teeth. When bacteria feed on the sugars you eat, it forms acids. Over a prolonged period of time, the acids starting destroying the tooth enamel, hence causing tooth decay. Treatment: Brush teeth frequently. Get fillings Schedule regular dentist appointments Eat less sugary foods.

Role of Fat One primary role of fat is to be stored in the body as an ‘energy storage substance’, containing approximately 37.8 Kilojoules per gram of fat. The fat can be broken down to give glycerol and fatty acids. The glycerol can be converted to glucose by the liver and can then be used as a source of energy. Role of the liver in the metabolism of glucose (glucose →glycogen). This process is called Glucoregulation Glucoregulation is the maintenance of glucose inside the body. Hormone insulin is very important for regulation. Can cause some cells to store glucose in the form of glycogen Its absence can cause glycogen to break down into glucose. Glycogen is stored and released inside the liver.

Alimentary canal

Chemical digestion

balanced diet

teeth

liver and fat