Animals: Structure & Function Unit 4 Animals: Structure & Function

Learning Goal To learn more about the different macromolecules found in food sources and how they are broken down To investigate the roles of minerals and vitamins in the body To learn more about the 4 stages of food processing

Section 10.1 Function of Digestion

Introduction What I already Know about the Digestive System What I want to know more about What I learned about the Digestive System

Distribution of body fluids Living on a planet that is made up of mostly water, it is no surprise that WE are also made up of mostly water

Distribution of body fluids As you can see, based on the different compartments of fluid in the body, we are made up of 60% water And a few other things

Distribution of body fluids Water in the body is divided into 3 compartments: Cytoplasm inside the cells The fluid between the cells called interstitial fluid And fluid in the blood

Distribution of body fluids These compartments are also made up of 1000s of different kinds of molecules and ions, like: water, phosphates, hydrogen ions, and sodium ions These are inorganic (non-living) matter

Distribution of body fluids Other molecules, called organic molecules, are made up of hydrocarbons (hydrogen & carbons), and other atoms like oxygen, sulfur, and nitrogen Larger, more complex organic molecules, called macromolecules, are make up the nutrients we know as lipids, carbohydrates, proteins, & nucleic acids These nutrients are the raw materials that our bodies need to provide energy, to regulate cellular activities, and to build and repair tissues

Macromolecules Defined as: very large molecule made up of smaller molecules that are linked together Energy can be released from these macromolecules inside the body through our metabolism and cellular pathways These 4 macromolecules are ESSENTIAL to our existence, thus called essential nutrients

Macromolecules – pg. 403 Macromolecule Main Function Examples Carbohydrates Provide materials to build cell membranes Provide quick ENERGY for cells Lipids Store energy to be used later Cushion / insulate organs Make up cell membranes Proteins Provide structure in blood cells, tissues, and muscles Make enzymes that help speed up reactions in cells Provide immunity against infections Transport ions in cells Nucleic Acids Contain all human genetic information Direct how an organism grows Coordinate the production of proteins

Carbohydrates Carb’s are made up of three elements: 1. Carbon 2. Hydrogen 3. Oxygen These molecules usually provide quick energy to the body (made by photosynthesis, broken down by respiration) Important role in: Energy Metabolism Storage Cell structures

Carbohydrates There are 2 main types of carbohydrates : Simple Sugars: Monosaccharides Complex Sugars: Polysaccharides “Mono” = one “Saccharide” = Sugar Are carbohydrates made up of small rings of carbon, hydrogen, and oxygen Include: glucose, fructose, galactose “Poly” = many Are carbohydrates made up of large rings of carbon, hydrogen, and oxygen Include: glycogen, starch, and cellulose

Lipids Lipids are hydrophobic (water hating) molecules made up of Carbon, Hydrogen, and Oxygen They contain fewer polar O-H bonds than and more non polar C-H bonds than carbs Thus, they are insoluble in water but soluble in other nonpolar substances This is why water and oil do NOT mix This is an important property of cell membranes and help control what things can come in and out of our cells

Lipids Tri = Three They contain 3 Fatty Acids & 1 Glycerol Molecule The basic structure of a lipid is a molecule of glycerol attached to fatty acid chains, in the form of a Triglyceride Tri = Three They contain 3 Fatty Acids & 1 Glycerol Molecule

Lipids Lipids store LOTS of energy in the body, but are mainly found in the form of phospholipids within our cell membranes

Proteins Are made up of smaller sub-units (like Lego) of molecules called Amino Acids Most proteins are made up of 100s of amino acids joined together by a peptide bond into larger chains called polypeptides Proteins help build and repair muscles and cell membranes

Nucleic Acids Are responsible for directing the growth and development of all organic organisms using a special chemical code that is found in our genes The information is stored in our DNA, which helps us to not only control what happens in the body, but also make proteins using RNA The 2 types of Nucleic Acid are DNA – deoxyribonucleic acid RNA – ribonucleic acid

Braking down Macromolecules In order to use the nutrients of carbohydrates, lipids, and proteins taken in from food These Large Macromolecules have to be chemically broken down into smaller molecules in order to enter cells within the digestive system This is done through a reaction that adds water to the bonds in large macromolecules, called Hydrolysis Where the adding of H2O brakes large chains into smaller pieces

Braking down Macromolecules Sometimes the breakdown of a large macromolecule needs more help than just water In this case, they would use ENZYMES to help speed up how fast these molecules are broken down Read pg. 404 and give examples of enzymes used in the digestive tract / where they are found: Macromolecule Type of Enzyme Used / Where Carbohydrate Lipid Protein Nucleic Acid

Braking down Macromolecules

Roles of Vitamins & Minerals In addition to macromolecules, we need certain amounts of vitamins and minerals in our bodies in order to function Vitamins and Minerals are both organic and inorganic substances that help chemical reactions to take place in our body (like a neuron firing or our hearts beating) They also assist tissue development, growth, and immunity over time

Role of Water in the Body You already know that we are made up of lots of water, thus – it is has IMPORTANT roles in the body: Transporting dissolved nutrients into cells of the small intestine (SI) Flushing out toxins from cells Lubricating tissues and joints Forming essential body fluids (blood / mucus) Regulate body temperature (sweating if too hot) Eliminating waste through urinary system / sweat

How Animals get their Food Animals are heterotrophs – which means they cannot make their own food, and need to eat something from their environment in order to live Regardless of their size, shape, and food preferences, ALL ANIMALS get their food through 1 of 4 ways via a Feeding Mechanism

Use pg. 407 to complete the table Feeding Mechanism Description Example Filter Feeders Substrate Feeders Fluid Feeders Bulk Feeders

4 stages of Food Processing When an animal initially get food, it is not in a form that the body can use So it must DIGEST it in order to get the most nutrition out of it, where The digestive system breaks down food into useful substances that can be absorbed into the circulatory system through microvilli that line the small intestine of the digestive tract All of this takes place in 4 important steps

4 stages of Food Processing 4. Elimination The REMOVAL of undigested food that was not needed was solid waste from the body 3. Absorption The TRANSPORT of products from digestive phase into the circulatory system, which then send nutrients to the rest of the body – where needed 2. Digestion The BREAKDOWN of food mechanically and chemically processes into molecules small enough for cells in the body to take in and use properly 1. Ingestion The taking IN or EATING of food

Digestion & the Alimentary Canal To digest their food, most animals have a digestive tract that consists of a long open tube This tube is called the alimentary canal where it has a mouth at one end to take in food, and a anus at the other end to eliminate waste As food moves through this tube, different organs of the digestive system process the food in different ways

Digestion & the Alimentary Canal

Alimentary Canal Example – Earth Worm: Food enters the mouth and passes into The Pharynx (throat) and into The Esophagus, who channels the food into The Crop (stomach 1), where food is softened & stored The muscular Gizzard (stomach 2) churns & grinds food And then the food is further digested into the intestine

Digestion & the Alimentary Canal In more complex animals, food enters the mouth and is physically broken apart into smaller pieces by teeth Food is then broken down further as it moves along the digestive tract by the muscular contractions of the tube itself This process of PHYSICALLY breaking down food into smaller pieces = Mechanical Digestion

Digestion & the Alimentary Canal At the same time, many fluid-releasing glands in the mouth and further along the digestive tract add LIQUID and ENZYMES that help break down macromolecules (carbs, protein, lipids) into smaller molecules The adding of Enzymes / Liquids from glands to help digestion = CHEMICAL DIGESTIONS

Digestion & the Alimentary Canal

Human Digestive Tract