Compare and Contrast Process in Plants and Animals: Nutrient Procurement and Processing Lecture on Plant Nutrition I. Plant Nutrition A. Nutritional requirements of plants B. Routes for absorption of water and minerals across the roots C. Nutritional adaptations by plants Animal Nutrition II. Nutritional requirements of animals A. Food uptake in cells B. Variations in feeding mechanisms and digestive compartments in animals III. The Human Digestive System PLANT NUTRITION • What do you think are the important activities for the maintenance of life. • Enumerate the kinds of nutrients that organisms obtain from food. • Recite the different organs in the animal body that may be involved in digestion What are nutrients? • refers to any substance required for the growth and maintenance of an organism. What are two types of organisms based on the mode of nutrition? autotrophs organisms that obtain energy from sunlight and chemicals to produce their own food. heterotrophs organisms that cannot make their own food and obtain their energy from other organisms. What are nutritional requirements of plants? 1. water 2. carbon dioxide 3. essential nutrients or elements A. examples of macronutrients: C, H, O, N, K, Ca, Mg, P, S B. examples of micronutrients: Cl, Fe, B, Mn, Zn, Co, Mo PHLOEM XYLEM food and nutrients such as sugar and Water and mineral transport from roots amino acids from leaves to storage to aerial parts of the plant. organs and growing parts of plant. • This movement of substances is called translocation. • MovementBidirectional (Moves up or down the plant's stem from "source to sink") Unidirectional (Moves up the plant's stem) routes for the absorption of water and minerals across plant roots: Plasmodesmata (singular, plasmodesma) are small channels that directly connect the cytoplasm of neighboring plant cells to each other, establishing living bridges between cells • symplast route – through plasmodesmata • apoplast route – along cell walls Specialized absorptive structures: root hairs slender extensions of specialized epidermal cells that greatly increase the surface area available for absorption. root nodules localized swellings in roots of certain plants where bacterial cells exist symbiotically with the plant. The bacteria help the plant fix nitrogen and in turn, the bacteria are able to utilize some organic compounds provided by the plant. mycorrhizae (singular, mycorrhiza) a symbiotic interaction between a young root and a fungus. The fungus obtains sugars and nitrogen-containing compounds from root cells while the plant is able to get some scarce minerals that the fungus is better able to absorb • Draw a cross section of the root • On the drawing, use a red ball pen to trace the symplast route, and a blue ball pen to trace the apoplast route for the movement of water from the soil to the xylem. •ANIMAL NUTRITION Ask the learners to locate the table on Nutrition Facts on the package of the food or snack • that they brought in class. • 2. Call one or two learners to read aloud the kinds of nutrients listed in the Nutrition Facts table. • Example: A 100 g foil pack of peanuts may show the following kinds of nutrients: Fat, • Cholesterol, Carbohydrate, Protein, Sodium, Vitamins, Minerals e.g. Iron • 3. Ask the class what we need to eat and why. • Example: what we need to eat – rice, potato, meat, fish, fruits, vegetables, etc. • why we need to eat – to obtain energy for our activities, to grow, to provide our bodies with • materials for making bone and muscles, etc CALORIE • is a unit of energy • indicates the amount of energy contained in food. It • specifically refers to the amount of heat energy required to raise the temperature of 1 kg (2.2lb.) of water by 1oC (1.8oF). • The greater the number of Calories in a quantity of food, the greater energy it contains (Johnson and Raven, 1996). NUTRIOTIONAL REQUIREMENTS 1. Carbohydrates – serve as a major energy source for the cells in the body. These are usually obtained from grains, cereals, breads, fruits, and vegetables. -------- contain 4 Calories per gram. 2. Proteins – can also be used as an energy source but the body mainly uses these as building materials for cell structures and as enzymes, hormones, parts of muscles, and bones. Proteins come from dairy products, poultry, fish, meat, and grains. -------contain 4 Calories per gram. 3. Fats – are used to build cell membranes, steroid hormones, and other cellular structures; also used to insulate nervous tissue, and also serve as an energy source. Fats also contain certain fat- soluble vitamins that are important for good health. Fats are obtained from oils, margarine, butter, fried foods, meat, and processed snack foods. contain a -------higher amount of energy per gram than carbohydrates or proteins, about 9 Calories per 4. Essential Nutrients ----include substances that animals can only get from the foods they eat because they could not be synthesized inside the body A. Essential amino acids –needed for synthesis of proteins and enzymes • lysine, tryptophan, threonine, methionine, phenylalanine, leucine, isoleucine and valine B. Essential fatty acids – used for making special membrane lipids; an example is linoleic acid in humans C. Vitamins – organic molecules required in small amounts for normal metabolism; • examples include fat-soluble Vitamins A, D, E, K, and water-soluble Vitamins B, B2, B3,B12, C. D. Trace Elements or Minerals – inorganic nutrients needed by the body in minute amounts; these form part of enzymes, body tissues, and body fluids; • examples include: iodine, cobalt, zinc, molybdenum, manganese, selenium. • Carbohydrates, proteins, and fats are energy-rich compounds present in food. The energy in food is stored in in its chemical bonds. As body cells break the chemical bonds, energy is harvested to make ATP. • Essential amino acids, vitamins, and trace elements are important substances for good health. • Essential amino acids serve as building blocks for proteins, while vitamins and trace elements are necessary for many cellular chemical reactions. • Cite examples of the effects of certain essential nutrient deficiencies or extreme excess. (5) • Write in your notebook Food uptakes • I. phagocytosis – engulfment of organic fragments or big particles, eg. Pseudopod formation in Amoeba. • II. pinocytosis – uptake of extracellular fluid by a cell using small vesicles derived from the plasma membrane. FEEDING MECHANISM I. substrate-feeders – animals that live in or on their food source. Examples: earthworms that feed through the soil where they live in; caterpillars that eat through the leaves where they live on. II. filter-feeders – include many aquatic animals which draw in water and strain small organisms and food particles present in the medium. Examples: whales and coelenterates III. fluid-feeders – suck fluids containing nutrients from a living host. Examples: mosquitoes, leeches, head lice, aphids IV. bulk-feeders – eat relatively large chunks of food and have adaptations like jaws, teeth, tentacles, claws, pincers, etc. that help in securing the food and tearing it to pieces. Examples: snakes, cats, man digestive compartments in animals: 1.Food vacuoles in unicellular organisms – these fuse with lysosomes that contain hydrolytic enzymes. Example: food vacuole in a protozoa like Paramecium Gastrovascular cavity or incomplete digestive system – composed of a single through which food is taken in and where wastes are disposed of; it is a saclike body cavity. Examples: in the cnidarian Hydra and in flatworm Planaria 3. Complete digestive system – essentially like a tube with an opening at one end for taking in food (mouth) and an opening at the other end where unabsorbed waste materials are eliminated (anus). In between the mouth and anus, are specialized organs that carry out transport, processing, and absorption of digested nutrients. accessory organs for digestion in a complete digestive system: accessory organs for digestion in a complete digestive system: I. liver – secretes bile for emulsifying fats II. gallbladder – stores bile produced by the liver III. pancreas – secretes enzymes that break down all major food molecules; secretes buffers against HCl from the stomach; secretes the hormone insulin for control of glucose metabolism Drawing Activity or Laboratory Work • 1. Draw a Paramecium as seen from a visual aid. Label thefood vacuole. • 2. Observe and draw a Hydra or Planaria as seen from a visual aid. Label the gastrovascular cavity. • 3. Draw from a visual aid the complete digestive system of an invertebrate such as a cockroach or grasshopper. Label the parts such as: salivary glands, esophagus, crop, gizzard, gastric caeca, mesenteron, Malpighian tubules, small intestine (ileum), large intestine (colon), rectum,and anus. • 4. Draw the picture of a dissected toad. Label the following organs: mouth or buccal cavity, tongue, pharynx, esophagus, stomach, small intestine, large intestine (colon), cloaca, anus. Also find the accessory organs: liver, gallbladder, pancreas. Draw and label all the parts.
