Digestive System Flashcards
(19 cards)
Define: Digestion
Digestion is the mechanical process of breaking down foods into smaller components
What is the difference between mechanical and chemical digestion?
Chemical: Splits food into smaller chemical units by breaking bonds.
Mechanical: Is the physical fragmenting of food into smaller pieces.
The churning of food in the stomach is an example of what kind of digestion?
An example of extra cellular mechanical digestion, the activity physically mixes food but does not break any chemical bonds.
What is the alimentary canal?
Also known as the digestive tract, is the tube which food enters the body and exists as waste.
Contains: Mouth, pharynx, oesophagus, stomach, small intestine, large intestine and anus.
Define absorption:
Is the process by which the molecules are taken up from the digestive tract, into the cells.
Absorption of nutrient occurs in the small intestine.
Absorption of water occurs in the large intestine.
Why is mastication a useful precursor to the later chemical digestion of food?
Mastication,or chewing, provides an increase in the surface are for digestion. The action of digestive enzymes, and thus digestion, is able to proceed more rapidly when the surface area-to- volume ratio of the ingested food particles increase.
Name the four stages of the digestive system.
Ingestion(eating)
Digestion(breaking down)
Absorption
Egestion( removal from the body)
Define soluble :
Able to dissolve in solvent. For example, sugar is soluble in water because it dissolves to form sugar solution.
Why is bacteria in the digestive system important?
Can digest some substances that humans cannot digest, such as certain carbohydrates.
Reduce the chance of harmful bacteria multiplying and causing disease.
Produce some vitamins that human need, such as vitamins B and K.
What two sets of muscles in the gut wall are involved?
Circular muscles: which reduce the diameter of the gut when they contract.
Longitudinal muscles: which reduce the length of the gut when they contract.
How is food moved through the digestive system?
By a process call peristalsis.
Is a wave-like muscular contractions in the smooth wall of the gut which moves food through the alimentary canal.
Define catalyst:
A catalyst changes the rate of a chemical reaction without being changed by the reaction itself
Define assimilation:
Assimilation is the movement of digested food molecules into the cells of the body where they are used.
For example:
Glucose is used in respiration to provide energy.
Amino acids are used to build new proteins.
What does the stomach produce?
How is it useful?
The stomach produces hydrochloric acid. It kills harmful microorganism that might have been swallowed along with the food. The enzymes in the stomach work best in acidic conditions.
What is bile?
After it has been in the stomach, food travels to the small intestine. The enzymes in the small intestine work best in aconditions
What does the stomach produce?
How is it useful?
The stomach produces hydrochloric acid. It kills harmful microorganism that might have been swallowed along with the food. The enzymes in the stomach work best in acidic conditions.
What is bile?
After it has been in the stomach, food travels to the small intestine. The enzymes in the small intestine work best in aconditions
What does the stomach produce?
How is it useful?
The stomach produces hydrochloric acid. It kills harmful microorganism that might have been swallowed along with the food. The enzymes in the stomach work best in acidic conditions.
What is bile?
After it has been in the stomach, food travels to the small intestine. The enzymes in the small intestine work best in aconditions
