### process | digestion:

Acid digestion
* Most acid digestion takes places.
* is another wet oxidation technology.

Anaerobic digestion
* Most anaerobic digestion produces gases
  - natural gases
  - renewable natural gases
* is another biological process that utilizes microbes
  - method for forming gases from biomass
  - used to stabilize the sludge which is removed from the wastewater
* occurs in manure in the absence of oxygen.
* offers excellent odor control.
  - methane that can be burned to release energy
* stabilizes sewage sludge and destroys harmful bacteria.
* tends to be slow.

Carbohydrate digestion
* begins in the mouth due to the action of salivary amylase
  - mouth, and is broken down with the enzymes in saliva
* is under the control of the enzymes maltase, lactase, sucrase.

### process | digestion:

Chemical digestion
* Most chemical digestion begins in mouths.
* Most chemical digestion occurs in intestines
  - small intestines
* Most chemical digestion takes place in the stomach
  - uses enzymes
* are strong acids that dissolve food to form chyme.
* begins in the mouth and continues in the stomach
  - stomach, a large, hollow, pouchlike muscular organ
* breaks complex chemicals into simple ones.
* follows a number of steps.
* involves a. the molars.
* is accomplished by enzymes
  - carried out by secretions from the liver and pancreas
  - completed in the small intestine
  - speeded up the physical digestion of the food into smaller pieces
  - the physical breakdown of chunks of food into smaller pieces
  - when chemical reactions break down food
* refers to enzymatic breakdown of macromolecules into smaller molecules.
* starts with saliva and continues into the intestines.
* takes place in separate compartments protected by a thick secretion of mucus

Extracellular digestion
* Most extracellular digestion involves enzymes
  - takes places
* Some extracellular digestion occurs in cavities.
* begins in the pharynx with the secretion of hydrolytic enzymes
  - pharynx, with further digestion in the stomodaeum
* is much more common, and is typical of mammals, including humans.
* means that a. proteolytic enzymes are secreted into the gut.
* takes place within the central cavity of the sac-like body
  - digestive cavity

Fat digestion
* can only occur at the surface of fat globules.
* is aided by enzymes called lipases , also produced by the pancreas
  - inhibited with aging
* occurs by pancreatic lipase in small intestine.

Further digestion
* Most further digestion occurs in intestines.
* is carried on by bacteria in the soil of the absorption field.
* takes place in the lower part of the small intestine

Good digestion
* is the key to good health.
* means happiness and virtue.

Human digestion
* breaks down food physically and chemically in a multistep process.
* differs even further from the digestive systems of ruminants.

Incomplete digestion
* creates an environment where disease can begin and thrive.
* well-known cause of false results.

### process | digestion:

Mechanical digestion
* Most mechanical digestion begins in mouths
  - occurs in stomachs
* Some mechanical digestion occurs in mouths.
* breaks down food through chewing and churning.
* is simply the physical breaking apart of a substance into smaller particles
  - the physical breakdown of large pieces of food into smaller pieces
* occurs as three strong layers of muscle contract to produce a churning motion
  - mainly in the small intestine
* starts in the mouth and continues in to the stomach
  - into the stomach
* takes place when food is chewed, mixed, and churned.

Optimal digestion
* leads to elimination.
* occurs at degrees.

Physical digestion
* Most physical digestion occurs in the mouth.
* breaks large pieces into smaller ones.