Digestion Function (OCR)

10.1 The Function of Digestion What do you Remember? Draw and/or label the parts of the human digestive system that you can think of. The Digestive System: Overview Gr 10 Key Concepts: (pg. 396-398 ) - animal cells have a number of organelles enclosed by a cell membrane water and m...

10.1 The Function of Digestion What do you Remember? Draw and/or label the parts of the human digestive system that you can think of. The Digestive System: Overview Gr 10 Key Concepts: (pg. 396-398 ) - animal cells have a number of organelles enclosed by a cell membrane water and molecules pass through the cell membrane by means of different processes (osmosis and diffusion) - cellular respiration is the process by which cells generate energy that an organism requires - cell specialization is influenced by the contents of an individual cell's cytoplasm, by environmental factors such as temperature, and by secretions from neighbouring cells - groups of similarly specialized cells form tissues - animals have four major tissue types muscle, epithelial, connective, nervous - human body has 11 organ systems that interact with one another in order to perform the tasks necessary for survival and reproduction - the stomach is the major organ in the body's digestive system - the heart is the major organ in the body's circulatory system - the lungs are the major organs in the body's respiratory system Video: How the Digestive System Works Macromolecules and Living Systems There are three main fluid compartments in the body: The fluid is mostly water, making up more than 60%, but it also contains thousands of different kinds of molecules and ions. Macromolecules and Living Systems Organic compounds - molecules that have carbon as its basic building block Macromolecules - Larger and more complex assemblies of organic molecules - Also called essential nutrients that our body cannot make and must be obtained from food; needed to sustain life 4 Main Groups of Macromolecules Macromolecules are grouped into 4 major categories: carbohydrates, lipids (fats), proteins, nucleic acids Energy released and matter supplied from these macromolecules is used to maintain the body's METABOLISM→ all chemical processes carried out by cells to maintain life. 1. Carbohydrates - Carbohydrates always contain carbon, hydrogen, and oxygen – and almost always in the same proportion: 2 atoms of H, and one atom of O for every atom of C - ie: CH2O - Carbohydrates provide short-term or long-term energy storage. 1. Carbohydrates- 2 Main Types 1. Monosaccharides: mono means one, sacchar means sugar - known as simple sugars carbohydrates (3 to 7 C atoms); most common are: glucose, fructose, galactose - can also be disaccharides or two simple sugars put together examples: sucrose, maltose, lactose 2. Polysaccharides: poly means many more - complex carbohydrates that consist of many linked monosaccharides - commonly called polymers examples: starch, cellulose, glycogen. Interesting Info 2. Lipids (fats) - All lipids are insoluble in water - Basic structure= glycerol molecule (alcohol) with 3 C attached to 3 fatty acid chains - Store 2.25x more energy per gram than other macromolecules; some function as energy storing molecules - Examples: butter, lard, oils 3. Proteins - Proteins are the most structurally complex and functionally diverse macromolecule - Made up of hundreds of amino acids joined together by peptide bonds into one or more chains called polypeptide chains - Folded into specific 3D shapes determined by the sequence of the amino acids→ A protein’s structure determines its function Polypeptide Chain 4. Nucleic Acids - Direct growth and development of all organisms using a chemical code - Contain the organism’s genetic information - Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) Breaking Down Macromolecules - Macromolecules must be broken down into molecules small enough to be absorbed by cells lining the small intestine - The process used is called hydrolysis - During hydrolysis, a water molecule is added to the macromolecule; breaks down bonds within macromolecule - Hydrolysis needs the help of enzymes→ protein molecules secreted by cells lining the digestive tract; act as catalysts to speed up the breakdown of chemical bonds without being used up in the reaction Text pg. 404 The Role of Water in the Body Water makes up about 2/3's of the body's mass and it is essential to the proper functioning of the body's cells and organs! Water functions include: - transport of dissolved nutrients - flushing toxins - lubricating tissues, joints, eyeballs - forming essential body fluids - regulating body temperature - eliminating waste - How Animals Obtain Their Food - Organisms that cannot produce their own food (heterotrophs) must consume other organisms to obtain energy-yielding food - There are 4 types of feeding mechanisms and behaviours that animals use to obtain energy… 1. filter feeding 2. substrate feeding 3. fluid feeding 4. bulk feeding Q: Which mechanisms do humans use? The Four Stages of Food Processing Video: The Digestive Process The Four Stages of Food Processing Pill Camera Swallowed: Live Digestion Digestion and Alimentary Canal To digest food, most animals have an alimentary canal→ a long open tube (digestive tract): mouth at one end and an anus at the other to eliminate waste. More complex animals have teeth in the mouth in order to start the digestion process with mechanical digestion (breaking food into smaller pieces) before the remaining part of the digestive system undergoes the chemical digestion (enzyme breakdown). The Length of the Digestive Tract The length of the digestive tract varies according to feeding habit and metabolic requirements of organisms. Herbivores and omnivores have longer tracts than carnivores because the cellulose walls in plant tissues are more difficult to digest than animal tissues and they need more time to complete digestion. Practice Pg. 403 Table 10.1- Four Major Categories of Macromolecules[ Copy into your notes as a study tool] Pg. 406 #1, 2, 6 Pg. 410 #1-3, 6 Pg. 410 #7-10, 12, 14, 15