MOD 2

• Nutritional requirements of animals

  Relatively extensive and complex compared with the simple requirements of plants
• Nutrients used by animals

  • Carbohydrates
  • Lipids
  • Nucleic acids
  • Proteins
  • Minerals
  • Vitamins
• Carbohydrates


  The basic source of energy for all animals
• Animals obtain their carbohydrates from the external environment, compared with plants which synthesize carbohydrates by photosynthesis
• About one-half to two-thirds of the total calories every animal consumes daily are from carbohydrates
• Glucose


  The carbohydrate most often used as an energy source
• Glucose metabolism


  1. Metabolized during cellular respiration

  2. Part of the energy is used to synthesize adenosine triphosphate (ATP)
• Other useful carbohydrates


  • Maltose
  • Lactose
  • Sucrose
  • Starch
• Lipids


  Used to form cellular and organelle membranes, the sheaths surrounding nerve fibers, and certain hormones
• Fats


  A type of lipid that are extremely useful energy sources
• Nucleic acids


  Used for the construction of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and ATP
• Animals obtain their nucleic acids from plant and animal tissues, especially from cells that contain nuclei
• Nucleic acid digestion


  1. Broken down into nucleotides

  2. Absorbed into the cells
• Proteins


  • Form the framework of the animal body
  • Essential components of the cytoplasm, membranes, and organelles
  • Major components of muscles, ligaments, and tendons
  • Essential substances of enzymes
• Amino acids


  • 20 kinds of amino acids that proteins are composed of
  • Many can be synthesized, many others must be supplied in the diet
• Protein digestion


  1. Broken down into their constituent amino acids

  2. Absorbed into the body
• Minerals required by animals

  • Phosphorus
  • Sulfur
  • Potassium
  • Magnesium
  • Zinc
• Animals usually obtain these minerals when they consume plants
• Vitamins


  Organic compounds essential in trace amounts to the health of animals
• Types of vitamins


  • Water soluble
  • Fat soluble
• Water-soluble vitamins


  Must be consumed frequently
• Fat-soluble vitamins


  Stored in the liver in fat droplets
• Essential vitamins


  • Vitamin A for good vision
  • Vitamin B for substances used in cellular respiration (FAD, NAD, and coenzyme A)
  • Vitamin D to assist calcium absorption in the body
• Animals obtain their nutrients through a broad variety of feeding patterns
• Feeding patterns of aquatic organisms

  • Sponges feed on small particles of food that enter their pores
  • Sea cucumbers wave their tentacles about and trap food on their sticky surfaces
  • Mollusks, such as clams and oysters, feed by filtering materials through a layer of mucus in their gills
  • Certain arthropods feed exclusively on fluids
• Types of feeding


  • Food masses
  • Fluids
• Animals that feed on food masses usually have organs for seizing, chewing, and consuming food
• Types of animals by diet

  • Herbivores (eat only plants)
  • Carnivores (eat only other animals)
  • Omnivores (consume both plants and animals)
• Humans are typified as omnivores
• Nutrition


  The process of obtaining food and using it for growth, metabolism, and repair
• Nutrition in animals is as important as it is for plants
• Photosynthesis


  The process by which plants prepare their own food
• Animals cannot prepare their own food, hence they need to depend on plants or other animals for their food
• Ways animals derive their nutrition

  • Eating plants directly (herbivores)
  • Eating animals which have consumed plants (carnivores)
  • Eating both plants and animals (omnivores)
• All organisms require food for their survival and growth
• Components of food (nutrients)

  • Carbohydrates
  • Fats
  • Minerals
  • Proteins
  • Vitamins
• These components are complex and cannot be used directly, so they are broken down into simpler components by the process of digestion
• Ingestion


  The process of taking in food
• Methods of ingestion


  • Bees and hummingbirds sucking nectar from plants
  • Python swallowing its prey
  • Cattle feeding on grass
• Nutrition in animals depends upon the feeding habits of the animals