Chapter 33: Animal Nutrition

* Nutrition: food is taken in, taken apart, and taken up * Herbivores (plants or algae) vs. Carnivores (other animals) vs. Omnivores (All) * Most animals are opportunistic feeders – eat outside their standard diet when their usual foods aren’t available * Animals must eat * But, to survive and reproduce balance their consumption, storage, and use of food

33.1: AN ANIMAL’S DIET MUST SUPPLY CHEMICAL ENERGY, ORGANIC MOLECULES, AND ESSENIAL NUTRIENTS * Diet must satisfy 3 nutritional needs: * Chemical energy for cellular processes * Organic building blocks for macromolecules * Essential nutrients * Activities of animals depends on sources of chemical energy that is used to produce ATP * To meet the continuous requirement for ATP, animals ingest and digest nutrients * Carbohydrates, proteins, lipids for cellular respiration and energy storage
Essential Nutrients * Essential nutrients are preassembled organic molecules and minerals * Obtained from an animal’s diet * Include essential fatty acids and amino acids, vitamins, minerals * Key function: serve as substrates, coenzymes, and cofactors in biosynthetic reactions * Essential Fatty Acids and Amino Acids * Animals convert fatty acids to a variety of cellular components * Membrane phospholipids, signaling molecules, storage fats * Essential fatty acids – animals can’t synthesize (but plants can) * Contain one or more double bonds * Example: linoleic acids, seeds, grains * Essential amino acids – obtained from food in prefabricated form * Animals use a set of 20 amino acids to synthesize proteins * Animals can produce about half (as long as diet includes sulfur & organic nitrogen) * Many animals