BIOL 103 Lecture Notes - Gastrovascular Cavity, Intestinal Gland, Hydrolase
Document Summary
Nutrition & digestion chapter 39 (lecture material & textbook) Autotroph: self-nutrition; harvest energy and store it (plants) Heterotroph: get complex nutrients from environment; eat other organisms for energy (higher trophic level) (animals) Essential nutrients include: essential amino acids, essential fatty acids, minerals, and vitamins. Easily obtained by carnivores, as meat contains all 20 amino acids. Polyunsaturated fats are found mainly in plants (herbivores/omnivores); also obtained from fish or tissue of birds and mammals. Very small amounts required every day; some minerals are secreted from bone (calcium) and other mineral storage areas into the blood. Two types: fat soluble (already stored in body) and water soluble (must be ingested regularly ex. Consists of enzymes to break down lipids, proteins, and nucleic acids by hydrolyzing the bonds: these enzymes consist of polysaccharidases, lipases, proteases, and nucleases. Digestion is only needed to convert polymers into smaller units so that they may be absorbed across membranes.
