Diet & Digestion Flashcards
(34 cards)
What happens in the mouth and salivary glands?
Mechanical digestion - teeth chew food to break it into smaller pieces and increase the surface area to volume ratio.
Chemical digestion - amylase enzymes in saliva start digesting starch into maltose.
What is the oesophagus?
It is the tube that connects the mouth to the stomach.
What happens in the stomach?
Food is mechanically digested by churning actions while protease enzymes start to chemically digest proteins.
Hydrochloric acid is present to kill bacteria in food and provide optimum pH for protease enzymes to work.
What is the first section of the small intestine called?
Duodenum
What happens in the duodenum?
Where digestion of the food exiting the stomach is completed by enzymes that are present in the duodenum lining and secreted by the pancreas.
What is the ph of the small intestine?
Slightly alkaline - around pH 8/9
What is the second section of the small intestine called?
The ileum
What happens in the ileum?
Where the absorption of water and digested food molecules takes place.
How is the ileum adapted for absorption?
It is long and lined with villi to increase the surface area over which absorption can take place
What happens in the oesophagus?
Wave like contractions (peristalsis) takes place to push the food bolus down without relying on gravity.
What happens in the large intestine?
Water is absorbed from the remaining material in the colon to produce faeces.
Where is faeces stored?
Faeces are stored in the rictus and exit the body via the anus.
What digestive enzymes are produced in the pancreas?
Amylase
Protease
Lipase
What happens in the pancreas?
Secretes enzymes into the duodenum for digestion
What happens in the liver?
Amino acids that are not used to make proteins are broken down here (desalination) - producing urea.
Bile is produced to emulsify fats (break large droplets into smaller droplets)
What is ingestion?
The taking in of substances, e.g. food and drink, into the body through the mouth.
What is mechanical digestion?
The breakdown of food into smaller pieces without chemical change to the food molecules.
What is chemical digestion?
Th breakdown of large, insoluble molecules into small, soluble molecules.
What is assimilation?
The movement of small molecules into the cells of the body where they are used, becoming part of the cells.
What is absorbtion?
The movement of small food molecules and ions through the wall of the intestine into the blood.
What is peristalsis?
The waves of contractions of circular muscles that push the bolus down the oesophagus.
Amylase breaks starch into…
Maltose
Where is amylase made?
Salivary glands
Pancreas
Small intestine
