Plant and Animal Nutrition

Cards (70)

  • nutrient - refers to any substance required for the growth and maintenance of an organism
  • two types of organisms based on the mode of nutrition:
    1. autotrophs
    2. heterotrophs
  • 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 organism
  • macronutrients - are those nutrients needed by all plants in relatively large amounts
  • macronutrients:
    1. nitrogen
    2. phosphorus
    3. potassium
    4. sulphur
    5. magnesium
    6. calcium
  • nitrogen - usually absorbed in the form of nitrate
  • nitrogen - needed for proper leaf growth and development
  • nitrogen - deficiency may produce yellowing of older leaves
  • nitrogen - excess produces hypertrophy of foliage and suppresses fruit production
  • potassium - important for maintaining the membrane potential of plant cells(turgidity)
  • potassium - deficiency produces general symptoms of poor health, which can include localized chlorosis(low chlorophyll)
  • phosphorus - essential for the production of such vital compounds as the nucleic acids and ATP
  • phosphorus - needed for flowering, fruiting, and root development
  • phosphorus - deficiency results in small dark green leaves over the entire plant
  • sulfur - essential component of protein because of its occurrence in the amino acids cysteine and methionine
  • sulfur - Deficiency produces chlorosis in new leaves and buds
  • sulfur - cannot be absorbed in elemental form but must be present as sulfate
  • calcium - important component of the middle lamella of cell walls
  • calcium - deficiency results in abnormal growth and cell division
  • magnesium - required for the action of many enzymes and is needed also in the synthesis of chlorophyll
  • magnesium - deficiency, therefore, produces mottled chlorosis
  • iron - needed in several of the electron transport substances of the cell (ferredoxin, cytochromes)
  • iron - can occur in soils with high or low pH
  • micronutrients - vitamins and minerals that are needed in small amounts
  • micronutrients:
    1. boron
    2. copper
    3. iron
    4. chloride
    5. manganese
    6. molybdenum
    7. zinc
  • boron - deficiency results in abnormally dark foliage, growth abnormalities, and malformations
  • zinc- required for the production of amino acid tryptophan
  • zinc - indirectly required for the production of auxins
  • zinc - Deficiency produces small leaves and stunted stems owing to short internodes.
  • zinc - poisonous to plants
  • manganese - required as a cofactor for enzymes in oxidative metabolism and in photosynthetic oxygen production.
  • manganese - Its deficiency produces a mottled, characteristic form of chlorotic leaf yellowing.
  • chlorine - required for ionic balance and maintenance of cellular membrane potentials
  • chlorine - its deficiency results in very small leaves and slow growth. Leaves become wilted, chlorotic, or even necrotic and may eventually become bronze-colored.
  • molybdenum - needed as part of the denitrifying and nitrogen-fixing enzymes of microorganisms
  • copper - component of some enzymes and cytochromes.
  • copper - deficiency results in a lowered rate of protein synthesis and sometimes in chlorosis
  • specialized absorptive structures:
    1. root hairs
    2. root nodules
    3. mycorrhizae
  • root hairs – slender extensions of specialized epidermal cells that greatly increase the surface area available for absorption.